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[[File:Jet.jpg|thumb|right|Flow visualization of a turbulent jet, made by [[Planar laser-induced fluorescence|laser-induced fluorescence]].  The jet exhibits a wide range of length scales, an important characteristic of turbulent flows.]]
[[File:Los Angeles attack sub 2.jpg|thumb|right|Laminar and turbulent water flow over the hull of a submarine]]
[[File:Airplane vortex edit.jpg|thumb|right|Turbulence in the [[Wingtip vortices|tip vortex]] from an [[airplane]] wing]]
 
In [[fluid dynamics]], '''turbulence''' or '''turbulent flow''' is a flow regime characterized by [[Chaos theory|chaotic]] property changes.  This includes low [[momentum diffusion]], high momentum [[convection]], and rapid variation of [[pressure]] and [[velocity]] in space and time.
 
Flow in which the [[kinetic energy]] dies out due to the action of fluid molecular [[viscosity]] is called [[laminar flow]]. While there is no theorem relating the non-dimensional [[Reynolds number]] (Re) to turbulence, flows at Reynolds numbers larger than 5000 are typically (but not necessarily) turbulent, while those at low Reynolds numbers usually remain laminar. In [[Hagen-Poiseuille equation|Poiseuille flow]], for example, turbulence can first be sustained if the Reynolds number is larger than a critical value of about 2040;<ref name=Recrit>{{cite journal|last=Avila|first=K.|coauthors=D. Moxey, A. de Lozar, M. Avila, D. Barkley, B. Hof|title=The Onset of Turbulence in Pipe Flow|journal=Science|date=July 2011|volume=333|issue=6039|pages=192–196|doi=10.1126/science.1203223|url=http://www.sciencemag.org/content/333/6039/192|bibcode = 2011Sci...333..192A }}</ref> moreover, the turbulence is generally interspersed with laminar flow until a larger Reynolds number of about 4000.
 
In turbulent flow, unsteady vortices appear on many scales and interact with each other. [[Drag (physics)|Drag]] due to [[boundary layer]] skin friction increases. The structure and location of boundary layer separation often changes, sometimes resulting in a reduction of overall drag. Although [[laminar-turbulent transition]] is not governed by Reynolds number, the same transition occurs if the size of the object is gradually increased, or the [[viscosity]] of the fluid is decreased, or if the [[density]] of the fluid is increased. [[Nobel Laureate]] [[Richard Feynman]] described turbulence as "the most important unsolved problem of classical physics."<ref>{{cite news| url=http://www.usatoday.com/tech/science/columnist/vergano/2006-09-10-turbulence_x.htm | work=USA Today | title=Turbulence theory gets a bit choppy | date=September 10, 2006}}</ref> 
 
==Features==
Turbulence is characterized by the following features:
 
* Irregularity: Turbulent flows are always highly irregular. This is why turbulence problems are normally treated statistically rather than deterministically. Turbulent flow is chaotic. However, not all chaotic flows are turbulent.
* Diffusivity: The readily available supply of energy in turbulent flows tends to accelerate the homogenization (mixing) of fluid mixtures.  The characteristic which is responsible for the enhanced mixing and increased rates of mass, momentum and energy transports in a flow is called "diffusivity".
* [[Rotationality]]: Turbulent flows have non-zero vorticity and are characterized by a strong three-dimensional vortex generation mechanism known as [[vortex stretching]]. In fluid dynamics, they are essentially vortices subjected to stretching associated with a corresponding increase of the component of vorticity in the stretching direction—due to the conservation of angular momentum. On the other hand, vortex stretching is the core mechanism on which the turbulence energy cascade relies to establish the structure function. In general, the stretching mechanism implies thinning of the vortices in the direction perpendicular to the stretching direction due to volume conservation of fluid elements. As a result, the radial length scale of the vortices decreases and the larger flow structures break down into smaller structures. The process continues until the small scale structures are small enough that their kinetic energy can be transformed by the fluid's molecular viscosity into heat. This is why turbulence is always rotational and three dimensional. For example, atmospheric cyclones are rotational but their substantially two-dimensional shapes do not allow vortex generation and so are not turbulent. On the other hand, oceanic flows are dispersive but essentially non rotational and therefore are not turbulent.
* [[Dissipation]]: To sustain turbulent flow, a persistent source of energy supply is required because turbulence dissipates rapidly as the kinetic energy is converted into internal energy by viscous shear stress.
Turbulent diffusion is usually described by a turbulent [[diffusion coefficient]]. This turbulent diffusion coefficient is defined in a phenomenological sense, by analogy with the molecular diffusivities, but it does not have a true physical meaning, being dependent on the flow conditions, and not a property of the fluid itself. In addition, the turbulent diffusivity concept assumes a constitutive relation between a turbulent [[flux]] and the gradient of a mean variable similar to the relation between flux and gradient that exists for molecular transport. In the best case, this assumption is only an approximation. Nevertheless, the turbulent diffusivity is the simplest approach for quantitative analysis of turbulent flows, and many models have been postulated to calculate it. For instance, in large bodies of water like oceans this coefficient can be found using [[Lewis Fry Richardson|Richardson]]'s four-third power law and is governed by the [[random walk]] principle.  In rivers and large ocean currents, the diffusion coefficient is given by variations of Elder's formula.
 
Turbulence causes the formation of [[Eddy (fluid dynamics)|eddies]] of many different length scales. Most of the kinetic energy of the turbulent motion is contained in the large-scale structures. The energy "cascades" from these large-scale structures to smaller scale structures by an inertial and essentially [[Inviscid flow|inviscid]] mechanism.  This process continues, creating smaller and smaller structures which produces a hierarchy of eddies.  Eventually this process creates structures that are small enough that molecular diffusion becomes important and viscous dissipation of energy finally takes place.  The scale at which this happens is the [[Kolmogorov microscales|Kolmogorov length scale]].
 
Via this [[energy cascade]], turbulent flow can be realized as a superposition of a spectrum of velocity fluctuations and eddies upon a [[mean flow]]. The eddies are loosely defined as coherent patterns of velocity, vorticity and pressure. Turbulent flows may be viewed as made of an entire hierarchy of eddies over a wide range of length scales and the hierarchy can be described by the energy spectrum that measures the energy in velocity fluctuations for each length scale ([[wavenumber]]). The scales in the energy cascade are generally uncontrollable and highly non-symmetric. Nevertheless, based on these length scales these eddies can be divided into three categories.
# [[Integral length scales]]: Largest scales in the energy spectrum. These eddies obtain energy from the mean flow and also from each other. Thus, these are the energy production eddies which contain most of the energy. They have the large velocity fluctuation and are low in frequency. Integral scales are highly [[anisotropic]] and are defined in terms of the normalized two-point velocity correlations. The maximum length of these scales is constrained by the characteristic length of the apparatus. For example, the largest integral length scale of pipe flow is equal to the pipe diameter. In the case of atmospheric turbulence, this length can reach up to the order of several hundreds kilometers.
# [[Kolmogorov microscales|Kolmogorov length scales]]: Smallest scales in the spectrum that form the viscous sub-layer range. In this range, the energy input from nonlinear interactions and the energy drain from viscous dissipation are in exact balance. The small scales have high frequency, causing turbulence to be locally [[isotropic]] and homogeneous.
# [[Taylor microscale]]s: The intermediate scales between the largest and the smallest scales which make the inertial subrange. Taylor micro-scales are not dissipative scale but pass down the energy from the largest to the smallest without dissipation. Some literatures do not consider Taylor micro-scales as a characteristic length scale and consider the energy cascade to contain only the largest and smallest scales; while the latter accommodate both the inertial sub-range and the viscous-sub layer. Nevertheless, Taylor micro-scales are often used in describing the term “turbulence” more conveniently as these Taylor micro-scales play a dominant role in energy and momentum transfer in the wavenumber space.
 
Although it is possible to find some particular solutions of the [[Navier-Stokes equations]] governing fluid motion, all such solutions are unstable to finite perturbations at large Reynolds numbers. Sensitive dependence on the initial and boundary conditions makes fluid flow irregular both in time and in space so that a statistical description is needed. [[Russia]]n mathematician [[Andrey Kolmogorov]] proposed the first statistical theory of turbulence, based on the aforementioned notion of the energy cascade (an idea originally introduced by [[Lewis Fry Richardson|Richardson]]) and the concept of self-similarity.  As a result, the [[Kolmogorov microscales]] were named after him. It is now known that the self-similarity is broken so the statistical description is presently modified.<ref>[http://www.weizmann.ac.il/home/fnfal/papers/PhysToday.pdf weizmann.ac.il]</ref> Still, a complete description of turbulence remains one of the [[unsolved problems in physics]].
 
According to an apocryphal story, [[Werner Heisenberg]] was asked what he would ask [[God]], given the opportunity. His reply was: "When I meet God, I am going to ask him two questions: Why [[Theory of relativity|relativity]]? And why turbulence? I really believe he will have an answer for the first."<ref>{{cite book|last=MARSHAK|first=ALEX|title=3D radiative transfer in cloudy atmospheres; pg.76|url=http://books.google.com/books?id=wzg6wnpHyCUC|year=2005|publisher=[[Springer Science+Business Media|Springer]]|isbn=978-3-540-23958-1}}</ref> A similar witticism has been attributed to [[Horace Lamb]] (who had published a noted text book on [[Hydrodynamics]])—his choice being [[quantum electrodynamics]] (instead of relativity) and turbulence. Lamb was quoted as saying in a speech to the [[British Association for the Advancement of Science]], "I am an old man now, and when I die and go to heaven there are two matters on which I hope for enlightenment. One is quantum electrodynamics, and the other is the turbulent motion of fluids. And about the former I am rather optimistic."<ref>{{cite journal|last=Mullin|first=Tom|date=11 November 1989|title=Turbulent times for fluids|journal=[[New Scientist]]|accessdate=1 November 2010}}</ref><ref>{{cite book|last=Davidson|first=P. A.|title=Turbulence: An Introduction for Scientists and Engineers|url=http://books.google.com/?id=rkOmKzujZB4C&pg=PA24&dq=%22when+I+die+and+go+to+Heaven+there+are+two+matters+on+which+I+hope+for+enlightenment%22#v=onepage&q=%22when%20I%20die%20and%20go%20to%20Heaven%20there%20are%20two%20matters%20on%20which%20I%20hope%20for%20enlightenment%22&f=false|year=2004|publisher=[[Oxford University Press]]|isbn=978-0-19-852949-1}}</ref>
 
A more detailed presentation of turbulence with emphasis on high-Reynolds number flow, intended for a general readership of physicists and applied mathematicians, is found in the Scholarpedia articles by R. Benzi and U. Frisch<ref>[http://www.scholarpedia.org/article/Turbulence scholarpedia.org]; R. Benzi and [[Uriel Frisch|U. Frisch]], Scholarpedia, "Turbulence".</ref> and by G. Falkovich.<ref>[http://www.scholarpedia.org/article/Cascade_and_scaling scholarpedia.org]; G. Falkovich, Scholarpedia, "Cascade and scaling".</ref>
 
== Examples of turbulence ==
 
* Smoke rising from a [[cigarette]] is turbulent flow. For the first few centimeters, the flow is certainly [[Laminar flow|laminar]]. Then smoke becomes turbulent as its [[Reynolds number]] increases, as its velocity and characteristic length are both increasing.
* Flow over a [[golf ball]]. (This can be best understood by considering the golf ball to be stationary, with air flowing over it.) If the golf ball were smooth, the boundary layer flow over the front of the sphere would be laminar at typical conditions. However, the boundary layer would separate early, as the pressure gradient switched from favorable (pressure decreasing in the flow direction) to unfavorable (pressure increasing in the flow direction), creating a large region of low pressure behind the ball that creates high [[form drag]].  To prevent this from happening, the surface is dimpled to perturb the boundary layer and promote transition to turbulence. This results in higher skin friction, but moves the point of boundary layer separation further along, resulting in lower form drag and lower overall drag.
* The mixing of warm and cold air in the atmosphere by wind, which causes [[clear-air turbulence]] experienced during airplane flight, as well as poor [[astronomical seeing]] (the blurring of images seen through the atmosphere.)
* Most of the terrestrial [[atmospheric circulation]]
* The oceanic and atmospheric [[mixed layer]]s and intense oceanic currents.
* The flow conditions in many industrial equipment (such as pipes, ducts, precipitators, gas [[scrubber]]s, [[dynamic scraped surface heat exchanger]]s, etc.) and machines (for instance, [[internal combustion engine]]s and [[gas turbine]]s).
* The external flow over all kind of vehicles such as cars, airplanes, ships and submarines.
* The motions of matter in stellar atmospheres.
* A jet exhausting from a nozzle into a quiescent fluid. As the flow emerges into this external fluid, shear layers originating at the lips of the nozzle are created. These layers separate the fast moving jet from the external fluid, and at a certain critical [[Reynolds number]] they become unstable and break down to turbulence.
{{unsolved|physics|Is it possible to make a theoretical model to describe the behavior of a turbulent flow — in particular, its internal structures?}}
* Race cars unable to follow each other through fast corners due to turbulence created by the leading car causing [[understeer]].
* In windy conditions, trucks that are on the motorway are buffetted by their wake.
* Bridge supports (piers) in water. In the late summer and fall, when river flow is slow, water flows smoothly around the support legs. In the spring, when the flow is faster, a higher Reynolds Number is associated with the flow.  The flow may start off laminar but is quickly separated from the leg and becomes turbulent.
* In many geophysical flows (rivers, atmospheric boundary layer), the flow turbulence is dominated by the coherent structure activities and associated turbulent events. A turbulent event is a series of turbulent fluctuations that contain more energy than the average flow turbulence.<ref name="Narasimha">{{cite journal|author=Narasimha R, Rudra Kumar S, Prabhu A, Kailas SV |title= Turbulent flux events in a nearly neutral atmospheric boundary layer|journal=Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences|volume=365|issue=1852|pages=841–858 |publisher=Phil Trans R Soc Ser A, Vol. 365, pp. 841–858 |year=2007 |isbn= | doi=10.1098/rsta.2006.1949|bibcode = 2007RSPTA.365..841N }}</ref><ref name="Trevethan_Chanson">{{cite journal|author=Trevethan M, [[Hubert Chanson|Chanson H]] |title= Turbulence and Turbulent Flux Events in a Small Estuary|journal=Environmental Fluid Mechanics|volume=10|issue=3|pages=345–368 |publisher=Environmental Fluid Mechanics, Vol. 10, pp. 345-368 |year=2010 |isbn= | doi=10.1007/s10652-009-9134-7 |url=http://espace.library.uq.edu.au/view/UQ:205133}}</ref> The turbulent events are associated with coherent flow structures such as eddies and turbulent bursting, and they play a critical role in terms of sediment scour, accretion and transport in rivers as well as contaminant mixing and dispersion in rivers and estuaries, and in the atmosphere.
* In the medical field of [[cardiology]], a stethoscope is used to detect [[heart sounds]] and [[bruits]], which are due to turbulent blood flow.  In normal individuals, heart sounds are a product of turbulent flow as heart valves close.  However, in some conditions turbulent flow can be audible due to other reasons, some of them pathological. For example, in advanced [[atherosclerosis]], bruits (and therefore turbulent flow) can be heard in some vessels that have been narrowed by the disease process.
 
==Heat and momentum transfer==
 
When flow is turbulent, particles exhibit additional transverse motion which enhances the rate of energy and momentum exchange between them thus increasing the [[heat transfer coefficient|heat transfer]] and the [[friction]] coefficient.
 
Assume for a two-dimensional turbulent flow that one was able to locate a specific point in the fluid and measure the actual velocity <math>v=\left( {{v}_{x}},{{v}_{y}} \right)</math> of every particle that passed through that point at any given time. Then one would find the actual velocity fluctuating about a mean value:
 
<math>{{v}_{x}}=\underbrace{\overline{{{v}_{x}}}}_{\begin{smallmatrix}
\text{mean} \\
\text{value}
\end{smallmatrix}}+\underbrace{{{{{v}'}}_{x}}}_{\text{fluctuation}}\text{  }\text{,  }{{v}_{y}}=\overline{{{v}_{y}}}+{{{v}'}_{y}}</math>
 
and similarly for temperature <math>\left( T=\overline{T}+{T}' \right)</math> and pressure <math>\left( P=\overline{P}+{P}' \right)</math>, where the primed quantities denote fluctuations superposed to the mean.
This decomposition of a flow variable into a mean value and a turbulent fluctuation was originally proposed by Osborne Reynolds in 1895, and is considered to be the beginning of the systematic mathematical analysis of turbulent flow, as a sub-field of fluid dynamics. While the mean values are taken as predictable variables determined by dynamics laws, the turbulent fluctuations are regarded as stochastic variables.
 
The heat flux and momentum transfer (represented by the shear stress <math>\tau </math>) in the direction normal to the flow for a given time are
 
<math>\begin{align}
  & q=\underbrace{{{{{v}'}}_{y}}\rho {{c}_{P}}{T}'}_{\text{experimental value}}=-{{k}_{\text{turb}}}\frac{\partial \overline{T}}{\partial y} \\
& \tau =\underbrace{-\rho \overline{{{{{v}'}}_{y}}{{{{v}'}}_{x}}}}_{\text{experimental value}}={{\mu }_{\text{turb}}}\frac{\partial \overline{{{v}_{x}}}}{\partial y} \\
\end{align}</math>
 
where <math>{{c}_{P}}</math> is the [[heat capacity]] at constant pressure, <math>\rho </math> is the density of the fluid, <math>{{\mu }_{\text{turb}}}</math> is the coefficient of turbulent [[viscosity]] and <math>{{k}_{\text{turb}}}</math> is the turbulent [[thermal conductivity]].
 
<ref>H. Tennekes and J. L. Lumley, "A First Course in Turbulence", The MIT Press, (1972).</ref>
 
==Kolmogorov's theory of 1941{{anchor|Kolmogorov's theory}}==
 
Richardson's notion of turbulence was that a turbulent flow is composed by "eddies" of different sizes. The sizes define a characteristic length scale for the eddies, which are also characterized by velocity scales and time scales (turnover time) dependent on the length scale. The large eddies are unstable and eventually break up originating smaller eddies, and the kinetic energy of the initial large eddy is divided into the smaller eddies that stemmed from it. These smaller eddies undergo the same process, giving rise to even smaller eddies which inherit the energy of their predecessor eddy,  and so on. In this way, the energy is passed down from the large scales of the motion to smaller scales until reaching a sufficiently small length scale such that the viscosity of the fluid can effectively dissipate the kinetic energy into internal energy.
 
In his original theory of 1941, [[Kolmogorov]] postulated that for very high [[Reynolds number]]s, the small scale turbulent motions are statistically isotropic (i.e. no preferential spatial direction could be discerned). In general, the large scales of a flow are not isotropic, since they are determined by the particular geometrical features of the boundaries (the size characterizing the large scales will be denoted as ''L''). Kolmogorov's idea was that in the Richardson's energy cascade this geometrical and directional information is lost, while the scale is reduced, so that the statistics of the small scales has a universal character: they are the same for all turbulent flows when the Reynolds number is sufficiently high.
 
Thus, Kolmogorov introduced a second hypothesis: for very high Reynolds numbers the statistics of small scales are universally and uniquely determined by the viscosity (<math>\nu</math>) and the rate of energy dissipation (<math>\varepsilon</math>). With only these two parameters, the unique length that can be formed by dimensional analysis is
 
:<math>\eta = \left(\frac{\nu^3}{\varepsilon}\right)^{1/4}</math>.
 
This is today known as the Kolmogorov length scale (see [[Kolmogorov microscales]]).
 
A turbulent flow is characterized by a hierarchy of scales through which the energy cascade takes place. Dissipation of kinetic energy takes place at scales of the order of Kolmogorov length <math>\eta</math>, while the input of energy into the cascade comes from the decay of the large scales, of order ''L''. These two scales at the extremes of the cascade can differ by several orders of magnitude at high Reynolds numbers. In between there is a range of scales (each one with its own characteristic length ''r'') that has formed at the expense of the energy of the large ones. These scales are very large compared with the Kolmogorov length, but still very small compared with the large scale of the flow (i.e. <math>\eta \ll r \ll L</math>). Since eddies in this range are much larger than the dissipative eddies that exist at Kolmogorov scales, kinetic energy is essentially not dissipated in this range, and it is merely transferred to smaller scales until viscous effects become important as the order of the Kolmogorov scale is approached. Within this range inertial effects are still much larger than viscous effects, and it is possible to assume that viscosity does not play a role in their internal dynamics (for this reason this range is called "inertial range").
 
Hence, a third hypothesis of Kolmogorov was that at very high Reynolds number the statistics of scales in the range <math>\eta \ll r \ll L</math> are universally and uniquely determined by the scale ''r'' and the rate of energy dissipation <math>\varepsilon</math>.
 
The way in which the kinetic energy is distributed over the multiplicity of scales is a fundamental characterization of a turbulent flow. For homogeneous turbulence (i.e., statistically invariant under translations of the reference frame) this is usually done by means of the ''energy spectrum function'' <math>E(k)</math>, where ''k'' is the modulus of the wavevector corresponding to some harmonics in a Fourier representation of the flow velocity field '''u'''('''x'''):
 
:<math>\mathbf{u}(\mathbf{x}) = \iiint_{\mathbb{R}^3} \widehat{\mathbf{u}}(\mathbf{k})e^{i \mathbf{k \cdot x}} \mathrm{d}^3\mathbf{k}</math>,
 
where '''û'''('''k''') is the Fourier transform of the velocity field. Thus, ''E''(''k'')d''k'' represents the contribution to the kinetic energy from all the Fourier modes with ''k'' < |'''k'''| < ''k'' + d''k'', and therefore,
 
:<math>\frac{1}{2}\langle u_i u_i \rangle = \int_{0}^{\infty}E(k)\mathrm{d}k</math>,
 
where <math>1/2\langle u_i u_i \rangle</math> is the mean turbulent kinetic energy of the flow. The wavenumber ''k'' corresponding to length scale ''r'' is <math>k=2\pi/r</math>. Therefore, by dimensional analysis, the only possible form for the energy spectrum function according with the third Kolmogorov's hypothesis is
 
:<math>E(k) = C \varepsilon^{2/3} k^{-5/3} </math>,
 
where ''C'' would be a universal constant. This is one of the most famous results of Kolmogorov 1941 theory, and considerable experimental evidence has accumulated that supports it.<ref>[[Uriel Frisch|U. Frisch]]. ''Turbulence: The Legacy of A. N. Kolmogorov''. Cambridge University Press, 1995.[http://www.cambridge.org/catalogue/catalogue.asp?isbn=9780521457132]</ref>
 
In spite of this success, Kolmogorov theory is at present under revision. This theory implicitly assumes that the turbulence is statistically self-similar at different scales. This essentially means that the statistics are scale-invariant in the inertial range. A usual way of studying turbulent velocity fields is by means of velocity increments:
 
:<math>\delta \mathbf{u}(r) = \mathbf{u}(\mathbf{x} + \mathbf{r}) - \mathbf{u}(\mathbf{x})</math>;
 
that is, the difference in velocity between points separated by a vector '''r''' (since the turbulence is assumed isotropic, the velocity increment depends only on the modulus of '''r''').
Velocity increments are useful because they emphasize the effects of scales of the order of the separation ''r'' when statistics are computed.  The statistical scale-invariance implies that the scaling of velocity increments should occur with a unique scaling exponent <math>\beta</math>, so that when ''r'' is scaled by a factor <math>\lambda</math>,
 
:<math>\delta \mathbf{u}(\lambda r)</math>
 
should have the same statistical distribution as
 
:<math>\lambda^{\beta}\delta \mathbf{u}(r)</math>,
 
with <math>\beta</math> independent of the scale ''r''. From this fact, and other results of Kolmogorov 1941 theory, it follows that the statistical moments of the velocity increments (known as ''structure functions'' in turbulence) should scale as
 
:<math>\langle [\delta \mathbf{u}(r)]^n  \rangle = C_n \varepsilon^{n/3} r^{n/3}</math>,
 
where the brackets denote the statistical average, and the <math>C_n</math> would be universal constants.
 
There is considerable evidence that turbulent flows deviate from this behavior. The scaling exponents deviate from the ''n''/3 value predicted by the theory, becoming a non-linear function of the order ''n'' of the structure function. The universality of the constants have also been questioned. For low orders the discrepancy with the Kolmogorov ''n''/3 value is very small, which explain the success of Kolmogorov theory in regards to low order statistical moments. In particular, it can be shown that
when the energy spectrum follows a power law
 
:<math>E(k) \propto k^{-p}</math>,
 
with <math>1 < p < 3</math>, the second order structure function has also a power law, with the form
 
:<math>\langle [\delta \mathbf{u}(r)]^2  \rangle \propto r^{p-1} </math>,
 
Since the experimental values obtained for the second order structure function only deviate slightly from the 2/3 value predicted by Kolmogorov theory, the value for ''p'' is very near to 5/3 (differences are about 2%<ref>J. Mathieu and J. Scott ''An Introduction to Turbulent Flow''. Cambridge University Press, 2000.</ref>). Thus the "Kolmogorov -5/3 spectrum" is generally observed in turbulence. However, for high order structure functions the difference with the Kolmogorov scaling is significant, and the breakdown of the statistical self-similarity is clear. This behavior, and the lack of universality of the <math>C_n</math> constants, are related with the phenomenon of intermittency in turbulence. This is an important area of research in this field, and a major goal of the modern theory of turbulence is to understand what is really universal in the inertial range.
 
== See also ==
{{div col|cols=3}}
* [[Astronomical seeing]]
* [[Atmospheric dispersion modeling]]
* [[Chaos theory]]
* [[Clear-air turbulence]]
* [[Constructal theory]]
* [[Downdraft]]s
* [[Eddy covariance]]
* [[Fluid dynamics]]
** [[Darcy–Weisbach equation]]
** [[Eddy (fluid dynamics)|Eddy]]
** [[Navier-Stokes equations]]
** [[Large eddy simulation]]
** [[Poiseuille's law]]
** [[Lagrangian coherent structure]]
** [[Turbulence kinetic energy]]
* [[Mesocyclone]]s
* [[Navier-Stokes existence and smoothness]]
* [[Reynolds Number]]
* [[Swing bowling]]
* [[Taylor microscale]]
* [[Turbulence modeling]]
* [[Velocimetry]]
* [[Vortex]]
* [[Vortex generator]]
*[[Wake turbulence]]
*[[Wave turbulence]]
*[[Wingtip vortices]]
*[[Wind tunnel]]
*[[Different Types of Boundary Conditions in Fluid Dynamics]]
{{div col end}}
 
==References and notes==
{{reflist}}
 
==Further reading==
===General===
* [http://www.weizmann.ac.il/complex/falkovich/gregory-falkovich G Falkovich ]  and K.R. Sreenivasan. ''Lessons from hydrodynamic turbulence'', ''[[Physics Today]]'', vol. 59, no. 4, pages 43–49 (April 2006).[http://www.phy.olemiss.edu/~jgladden/phys510/spring06/turbulence.pdf]
* [[Uriel Frisch|U. Frisch]]. ''Turbulence: The Legacy of A. N. Kolmogorov''. Cambridge University Press, 1995.[http://www.cambridge.org/catalogue/catalogue.asp?isbn=9780521457132]
* P. A. Davidson. ''Turbulence - An Introduction for Scientists and Engineers''. Oxford University Press, 2004.
* J. Cardy, G. Falkovich and K. Gawedzki (2008) Non-equilibrium statistical mechanics and turbulence. Cambridge University Press [http://www.cambridge.org/gb/knowledge/isbn/item1164939/?site_locale=en_GB]
* P. A. Durbin and B. A. Pettersson Reif. ''Statistical Theory and Modeling for Turbulent Flows''. Johns Wiley & Sons, 2001.
* T. Bohr, M.H. Jensen, G. Paladin and A.Vulpiani. ''Dynamical Systems Approach to Turbulence'', Cambridge University Press, 1998.[http://www.cambridge.org/catalogue/catalogue.asp?isbn=9780521475143]
* J. M. McDonough (2007).  ''Introductory Lectures on Turbulence - Physics, Mathematics, and Modeling''[http://www.engr.uky.edu/~acfd/lctr-notes634.pdf]
 
===Original scientific research papers and classic monographs===
*{{cite journal
|last=Kolmogorov
|first=Andrey Nikolaevich
|authorlink=Andrey Nikolaevich Kolmogorov
|year=1941
|title=The local structure of turbulence in incompressible viscous fluid for very large Reynolds numbers
|journal=[[Proceedings of the USSR Academy of Sciences]]
|volume=30
|pages=299–303}} {{ru icon}}, translated into English by V. Levin: {{cite journal
|last=Kolmogorov
|first=Andrey Nikolaevich
|date=July 8, 1991
|title=The local structure of turbulence in incompressible viscous fluid for very large Reynolds numbers
|journal=[[Proceedings of the Royal Society A]]
|volume=434
|issue=1991
|pages=9–13
|url=http://www.csee.wvu.edu/~xinl/library/papers/physics/Kolmogorov_on_turbulence.pdf
|doi=10.1098/rspa.1991.0075
|bibcode = 1991RSPSA.434....9K }}
*{{cite journal
|last=Kolmogorov
|first=Andrey Nikolaevich
|authorlink=Andrey Nikolaevich Kolmogorov
|year=1941
|title=Dissipation of Energy in the Locally Isotropic Turbulence
|journal=[[Proceedings of the USSR Academy of Sciences]]
|volume=32
|pages=16–18}} {{ru icon}}, translated into English by {{cite journal
|last=Kolmogorov
|first=Andrey Nikolaevich
|date=July 8, 1991
|title=The local structure of turbulence in incompressible viscous fluid for very large Reynolds numbers
|journal=[[Proceedings of the Royal Society A]]
|volume=434
|issue=1980
|pages=15–17
|url=http://www.math.nyu.edu/caos_teaching/geophysical_turbulence/reading/Kolmogorov41.pdf
|doi=10.1098/rspa.1991.0076
|bibcode = 1991RSPSA.434...15K }}
* G. K. Batchelor, ''The theory of homogeneous turbulence''. Cambridge University Press, 1953.
 
== External links ==
* [http://www.stanford.edu/group/ctr/ Center for Turbulence Research], [[Stanford University]]
* [http://turb.seas.ucla.edu/~jkim/sciam/turbulence.html Scientific American article]
* [http://www.turbulenceforecast.com Air Turbulence Forecast]
* [http://cfd.cineca.it/ international CFD database iCFDdatabase]
* {{youtube|NplrDarMDF8|Turbulent flow in a pipe}}
*[http://www.weizmann.ac.il/complex/falkovich/fluid-mechanics Fluid Mechanics website with movies, Q&A, etc]
*[http://turbulence.pha.jhu.edu Johns Hopkins public database with direct numerical simulation data]
 
[[Category:Concepts in physics]]
[[Category:Aerodynamics]]
[[Category:Chaos theory]]
[[Category:Turbulence| ]]
[[Category:Transport phenomena]]
[[Category:Fluid dynamics]]

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Flow visualization of a turbulent jet, made by laser-induced fluorescence. The jet exhibits a wide range of length scales, an important characteristic of turbulent flows.
Laminar and turbulent water flow over the hull of a submarine
Turbulence in the tip vortex from an airplane wing

In fluid dynamics, turbulence or turbulent flow is a flow regime characterized by chaotic property changes. This includes low momentum diffusion, high momentum convection, and rapid variation of pressure and velocity in space and time.

Flow in which the kinetic energy dies out due to the action of fluid molecular viscosity is called laminar flow. While there is no theorem relating the non-dimensional Reynolds number (Re) to turbulence, flows at Reynolds numbers larger than 5000 are typically (but not necessarily) turbulent, while those at low Reynolds numbers usually remain laminar. In Poiseuille flow, for example, turbulence can first be sustained if the Reynolds number is larger than a critical value of about 2040;[1] moreover, the turbulence is generally interspersed with laminar flow until a larger Reynolds number of about 4000.

In turbulent flow, unsteady vortices appear on many scales and interact with each other. Drag due to boundary layer skin friction increases. The structure and location of boundary layer separation often changes, sometimes resulting in a reduction of overall drag. Although laminar-turbulent transition is not governed by Reynolds number, the same transition occurs if the size of the object is gradually increased, or the viscosity of the fluid is decreased, or if the density of the fluid is increased. Nobel Laureate Richard Feynman described turbulence as "the most important unsolved problem of classical physics."[2]

Features

Turbulence is characterized by the following features:

  • Irregularity: Turbulent flows are always highly irregular. This is why turbulence problems are normally treated statistically rather than deterministically. Turbulent flow is chaotic. However, not all chaotic flows are turbulent.
  • Diffusivity: The readily available supply of energy in turbulent flows tends to accelerate the homogenization (mixing) of fluid mixtures. The characteristic which is responsible for the enhanced mixing and increased rates of mass, momentum and energy transports in a flow is called "diffusivity".
  • Rotationality: Turbulent flows have non-zero vorticity and are characterized by a strong three-dimensional vortex generation mechanism known as vortex stretching. In fluid dynamics, they are essentially vortices subjected to stretching associated with a corresponding increase of the component of vorticity in the stretching direction—due to the conservation of angular momentum. On the other hand, vortex stretching is the core mechanism on which the turbulence energy cascade relies to establish the structure function. In general, the stretching mechanism implies thinning of the vortices in the direction perpendicular to the stretching direction due to volume conservation of fluid elements. As a result, the radial length scale of the vortices decreases and the larger flow structures break down into smaller structures. The process continues until the small scale structures are small enough that their kinetic energy can be transformed by the fluid's molecular viscosity into heat. This is why turbulence is always rotational and three dimensional. For example, atmospheric cyclones are rotational but their substantially two-dimensional shapes do not allow vortex generation and so are not turbulent. On the other hand, oceanic flows are dispersive but essentially non rotational and therefore are not turbulent.
  • Dissipation: To sustain turbulent flow, a persistent source of energy supply is required because turbulence dissipates rapidly as the kinetic energy is converted into internal energy by viscous shear stress.

Turbulent diffusion is usually described by a turbulent diffusion coefficient. This turbulent diffusion coefficient is defined in a phenomenological sense, by analogy with the molecular diffusivities, but it does not have a true physical meaning, being dependent on the flow conditions, and not a property of the fluid itself. In addition, the turbulent diffusivity concept assumes a constitutive relation between a turbulent flux and the gradient of a mean variable similar to the relation between flux and gradient that exists for molecular transport. In the best case, this assumption is only an approximation. Nevertheless, the turbulent diffusivity is the simplest approach for quantitative analysis of turbulent flows, and many models have been postulated to calculate it. For instance, in large bodies of water like oceans this coefficient can be found using Richardson's four-third power law and is governed by the random walk principle. In rivers and large ocean currents, the diffusion coefficient is given by variations of Elder's formula.

Turbulence causes the formation of eddies of many different length scales. Most of the kinetic energy of the turbulent motion is contained in the large-scale structures. The energy "cascades" from these large-scale structures to smaller scale structures by an inertial and essentially inviscid mechanism. This process continues, creating smaller and smaller structures which produces a hierarchy of eddies. Eventually this process creates structures that are small enough that molecular diffusion becomes important and viscous dissipation of energy finally takes place. The scale at which this happens is the Kolmogorov length scale.

Via this energy cascade, turbulent flow can be realized as a superposition of a spectrum of velocity fluctuations and eddies upon a mean flow. The eddies are loosely defined as coherent patterns of velocity, vorticity and pressure. Turbulent flows may be viewed as made of an entire hierarchy of eddies over a wide range of length scales and the hierarchy can be described by the energy spectrum that measures the energy in velocity fluctuations for each length scale (wavenumber). The scales in the energy cascade are generally uncontrollable and highly non-symmetric. Nevertheless, based on these length scales these eddies can be divided into three categories.

  1. Integral length scales: Largest scales in the energy spectrum. These eddies obtain energy from the mean flow and also from each other. Thus, these are the energy production eddies which contain most of the energy. They have the large velocity fluctuation and are low in frequency. Integral scales are highly anisotropic and are defined in terms of the normalized two-point velocity correlations. The maximum length of these scales is constrained by the characteristic length of the apparatus. For example, the largest integral length scale of pipe flow is equal to the pipe diameter. In the case of atmospheric turbulence, this length can reach up to the order of several hundreds kilometers.
  2. Kolmogorov length scales: Smallest scales in the spectrum that form the viscous sub-layer range. In this range, the energy input from nonlinear interactions and the energy drain from viscous dissipation are in exact balance. The small scales have high frequency, causing turbulence to be locally isotropic and homogeneous.
  3. Taylor microscales: The intermediate scales between the largest and the smallest scales which make the inertial subrange. Taylor micro-scales are not dissipative scale but pass down the energy from the largest to the smallest without dissipation. Some literatures do not consider Taylor micro-scales as a characteristic length scale and consider the energy cascade to contain only the largest and smallest scales; while the latter accommodate both the inertial sub-range and the viscous-sub layer. Nevertheless, Taylor micro-scales are often used in describing the term “turbulence” more conveniently as these Taylor micro-scales play a dominant role in energy and momentum transfer in the wavenumber space.

Although it is possible to find some particular solutions of the Navier-Stokes equations governing fluid motion, all such solutions are unstable to finite perturbations at large Reynolds numbers. Sensitive dependence on the initial and boundary conditions makes fluid flow irregular both in time and in space so that a statistical description is needed. Russian mathematician Andrey Kolmogorov proposed the first statistical theory of turbulence, based on the aforementioned notion of the energy cascade (an idea originally introduced by Richardson) and the concept of self-similarity. As a result, the Kolmogorov microscales were named after him. It is now known that the self-similarity is broken so the statistical description is presently modified.[3] Still, a complete description of turbulence remains one of the unsolved problems in physics.

According to an apocryphal story, Werner Heisenberg was asked what he would ask God, given the opportunity. His reply was: "When I meet God, I am going to ask him two questions: Why relativity? And why turbulence? I really believe he will have an answer for the first."[4] A similar witticism has been attributed to Horace Lamb (who had published a noted text book on Hydrodynamics)—his choice being quantum electrodynamics (instead of relativity) and turbulence. Lamb was quoted as saying in a speech to the British Association for the Advancement of Science, "I am an old man now, and when I die and go to heaven there are two matters on which I hope for enlightenment. One is quantum electrodynamics, and the other is the turbulent motion of fluids. And about the former I am rather optimistic."[5][6]

A more detailed presentation of turbulence with emphasis on high-Reynolds number flow, intended for a general readership of physicists and applied mathematicians, is found in the Scholarpedia articles by R. Benzi and U. Frisch[7] and by G. Falkovich.[8]

Examples of turbulence

  • Smoke rising from a cigarette is turbulent flow. For the first few centimeters, the flow is certainly laminar. Then smoke becomes turbulent as its Reynolds number increases, as its velocity and characteristic length are both increasing.
  • Flow over a golf ball. (This can be best understood by considering the golf ball to be stationary, with air flowing over it.) If the golf ball were smooth, the boundary layer flow over the front of the sphere would be laminar at typical conditions. However, the boundary layer would separate early, as the pressure gradient switched from favorable (pressure decreasing in the flow direction) to unfavorable (pressure increasing in the flow direction), creating a large region of low pressure behind the ball that creates high form drag. To prevent this from happening, the surface is dimpled to perturb the boundary layer and promote transition to turbulence. This results in higher skin friction, but moves the point of boundary layer separation further along, resulting in lower form drag and lower overall drag.
  • The mixing of warm and cold air in the atmosphere by wind, which causes clear-air turbulence experienced during airplane flight, as well as poor astronomical seeing (the blurring of images seen through the atmosphere.)
  • Most of the terrestrial atmospheric circulation
  • The oceanic and atmospheric mixed layers and intense oceanic currents.
  • The flow conditions in many industrial equipment (such as pipes, ducts, precipitators, gas scrubbers, dynamic scraped surface heat exchangers, etc.) and machines (for instance, internal combustion engines and gas turbines).
  • The external flow over all kind of vehicles such as cars, airplanes, ships and submarines.
  • The motions of matter in stellar atmospheres.
  • A jet exhausting from a nozzle into a quiescent fluid. As the flow emerges into this external fluid, shear layers originating at the lips of the nozzle are created. These layers separate the fast moving jet from the external fluid, and at a certain critical Reynolds number they become unstable and break down to turbulence.

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  • Race cars unable to follow each other through fast corners due to turbulence created by the leading car causing understeer.
  • In windy conditions, trucks that are on the motorway are buffetted by their wake.
  • Bridge supports (piers) in water. In the late summer and fall, when river flow is slow, water flows smoothly around the support legs. In the spring, when the flow is faster, a higher Reynolds Number is associated with the flow. The flow may start off laminar but is quickly separated from the leg and becomes turbulent.
  • In many geophysical flows (rivers, atmospheric boundary layer), the flow turbulence is dominated by the coherent structure activities and associated turbulent events. A turbulent event is a series of turbulent fluctuations that contain more energy than the average flow turbulence.[9][10] The turbulent events are associated with coherent flow structures such as eddies and turbulent bursting, and they play a critical role in terms of sediment scour, accretion and transport in rivers as well as contaminant mixing and dispersion in rivers and estuaries, and in the atmosphere.
  • In the medical field of cardiology, a stethoscope is used to detect heart sounds and bruits, which are due to turbulent blood flow. In normal individuals, heart sounds are a product of turbulent flow as heart valves close. However, in some conditions turbulent flow can be audible due to other reasons, some of them pathological. For example, in advanced atherosclerosis, bruits (and therefore turbulent flow) can be heard in some vessels that have been narrowed by the disease process.

Heat and momentum transfer

When flow is turbulent, particles exhibit additional transverse motion which enhances the rate of energy and momentum exchange between them thus increasing the heat transfer and the friction coefficient.

Assume for a two-dimensional turbulent flow that one was able to locate a specific point in the fluid and measure the actual velocity of every particle that passed through that point at any given time. Then one would find the actual velocity fluctuating about a mean value:

and similarly for temperature and pressure , where the primed quantities denote fluctuations superposed to the mean. This decomposition of a flow variable into a mean value and a turbulent fluctuation was originally proposed by Osborne Reynolds in 1895, and is considered to be the beginning of the systematic mathematical analysis of turbulent flow, as a sub-field of fluid dynamics. While the mean values are taken as predictable variables determined by dynamics laws, the turbulent fluctuations are regarded as stochastic variables.

The heat flux and momentum transfer (represented by the shear stress ) in the direction normal to the flow for a given time are

where is the heat capacity at constant pressure, is the density of the fluid, is the coefficient of turbulent viscosity and is the turbulent thermal conductivity.

[11]

Kolmogorov's theory of 1941<Kolmogorov's theory>...</Kolmogorov's theory>

Richardson's notion of turbulence was that a turbulent flow is composed by "eddies" of different sizes. The sizes define a characteristic length scale for the eddies, which are also characterized by velocity scales and time scales (turnover time) dependent on the length scale. The large eddies are unstable and eventually break up originating smaller eddies, and the kinetic energy of the initial large eddy is divided into the smaller eddies that stemmed from it. These smaller eddies undergo the same process, giving rise to even smaller eddies which inherit the energy of their predecessor eddy, and so on. In this way, the energy is passed down from the large scales of the motion to smaller scales until reaching a sufficiently small length scale such that the viscosity of the fluid can effectively dissipate the kinetic energy into internal energy.

In his original theory of 1941, Kolmogorov postulated that for very high Reynolds numbers, the small scale turbulent motions are statistically isotropic (i.e. no preferential spatial direction could be discerned). In general, the large scales of a flow are not isotropic, since they are determined by the particular geometrical features of the boundaries (the size characterizing the large scales will be denoted as L). Kolmogorov's idea was that in the Richardson's energy cascade this geometrical and directional information is lost, while the scale is reduced, so that the statistics of the small scales has a universal character: they are the same for all turbulent flows when the Reynolds number is sufficiently high.

Thus, Kolmogorov introduced a second hypothesis: for very high Reynolds numbers the statistics of small scales are universally and uniquely determined by the viscosity () and the rate of energy dissipation (). With only these two parameters, the unique length that can be formed by dimensional analysis is

.

This is today known as the Kolmogorov length scale (see Kolmogorov microscales).

A turbulent flow is characterized by a hierarchy of scales through which the energy cascade takes place. Dissipation of kinetic energy takes place at scales of the order of Kolmogorov length , while the input of energy into the cascade comes from the decay of the large scales, of order L. These two scales at the extremes of the cascade can differ by several orders of magnitude at high Reynolds numbers. In between there is a range of scales (each one with its own characteristic length r) that has formed at the expense of the energy of the large ones. These scales are very large compared with the Kolmogorov length, but still very small compared with the large scale of the flow (i.e. ). Since eddies in this range are much larger than the dissipative eddies that exist at Kolmogorov scales, kinetic energy is essentially not dissipated in this range, and it is merely transferred to smaller scales until viscous effects become important as the order of the Kolmogorov scale is approached. Within this range inertial effects are still much larger than viscous effects, and it is possible to assume that viscosity does not play a role in their internal dynamics (for this reason this range is called "inertial range").

Hence, a third hypothesis of Kolmogorov was that at very high Reynolds number the statistics of scales in the range are universally and uniquely determined by the scale r and the rate of energy dissipation .

The way in which the kinetic energy is distributed over the multiplicity of scales is a fundamental characterization of a turbulent flow. For homogeneous turbulence (i.e., statistically invariant under translations of the reference frame) this is usually done by means of the energy spectrum function , where k is the modulus of the wavevector corresponding to some harmonics in a Fourier representation of the flow velocity field u(x):

,

where û(k) is the Fourier transform of the velocity field. Thus, E(k)dk represents the contribution to the kinetic energy from all the Fourier modes with k < |k| < k + dk, and therefore,

,

where is the mean turbulent kinetic energy of the flow. The wavenumber k corresponding to length scale r is . Therefore, by dimensional analysis, the only possible form for the energy spectrum function according with the third Kolmogorov's hypothesis is

,

where C would be a universal constant. This is one of the most famous results of Kolmogorov 1941 theory, and considerable experimental evidence has accumulated that supports it.[12]

In spite of this success, Kolmogorov theory is at present under revision. This theory implicitly assumes that the turbulence is statistically self-similar at different scales. This essentially means that the statistics are scale-invariant in the inertial range. A usual way of studying turbulent velocity fields is by means of velocity increments:

;

that is, the difference in velocity between points separated by a vector r (since the turbulence is assumed isotropic, the velocity increment depends only on the modulus of r). Velocity increments are useful because they emphasize the effects of scales of the order of the separation r when statistics are computed. The statistical scale-invariance implies that the scaling of velocity increments should occur with a unique scaling exponent , so that when r is scaled by a factor ,

should have the same statistical distribution as

,

with independent of the scale r. From this fact, and other results of Kolmogorov 1941 theory, it follows that the statistical moments of the velocity increments (known as structure functions in turbulence) should scale as

,

where the brackets denote the statistical average, and the would be universal constants.

There is considerable evidence that turbulent flows deviate from this behavior. The scaling exponents deviate from the n/3 value predicted by the theory, becoming a non-linear function of the order n of the structure function. The universality of the constants have also been questioned. For low orders the discrepancy with the Kolmogorov n/3 value is very small, which explain the success of Kolmogorov theory in regards to low order statistical moments. In particular, it can be shown that when the energy spectrum follows a power law

,

with , the second order structure function has also a power law, with the form

,

Since the experimental values obtained for the second order structure function only deviate slightly from the 2/3 value predicted by Kolmogorov theory, the value for p is very near to 5/3 (differences are about 2%[13]). Thus the "Kolmogorov -5/3 spectrum" is generally observed in turbulence. However, for high order structure functions the difference with the Kolmogorov scaling is significant, and the breakdown of the statistical self-similarity is clear. This behavior, and the lack of universality of the constants, are related with the phenomenon of intermittency in turbulence. This is an important area of research in this field, and a major goal of the modern theory of turbulence is to understand what is really universal in the inertial range.

See also

Organisational Psychologist Alfonzo Lester from Timmins, enjoys pinochle, property developers in new launch singapore property and textiles. Gets motivation through travel and just spent 7 days at Alejandro de Humboldt National Park.

42 year-old Environmental Consultant Merle Eure from Hudson, really loves snowboarding, property developers in new launch ec singapore and cosplay. Maintains a trip blog and has lots to write about after visiting Chhatrapati Shivaji Terminus (formerly Victoria Terminus).

References and notes

43 year old Petroleum Engineer Harry from Deep River, usually spends time with hobbies and interests like renting movies, property developers in singapore new condominium and vehicle racing. Constantly enjoys going to destinations like Camino Real de Tierra Adentro.

Further reading

General

  • G Falkovich and K.R. Sreenivasan. Lessons from hydrodynamic turbulence, Physics Today, vol. 59, no. 4, pages 43–49 (April 2006).[1]
  • U. Frisch. Turbulence: The Legacy of A. N. Kolmogorov. Cambridge University Press, 1995.[2]
  • P. A. Davidson. Turbulence - An Introduction for Scientists and Engineers. Oxford University Press, 2004.
  • J. Cardy, G. Falkovich and K. Gawedzki (2008) Non-equilibrium statistical mechanics and turbulence. Cambridge University Press [3]
  • P. A. Durbin and B. A. Pettersson Reif. Statistical Theory and Modeling for Turbulent Flows. Johns Wiley & Sons, 2001.
  • T. Bohr, M.H. Jensen, G. Paladin and A.Vulpiani. Dynamical Systems Approach to Turbulence, Cambridge University Press, 1998.[4]
  • J. M. McDonough (2007). Introductory Lectures on Turbulence - Physics, Mathematics, and Modeling[5]

Original scientific research papers and classic monographs

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    Discover out more about real estate funding in the area, together with info on international funding incentives and property possession. Many Singaporeans have been investing in property across the causeway in recent years, attracted by comparatively low prices. However, those who need to exit their investments quickly are likely to face significant challenges when trying to sell their property – and could finally be stuck with a property they can't sell. Career improvement programmes, in-house valuation, auctions and administrative help, venture advertising and marketing, skilled talks and traisning are continuously planned for the sales associates to help them obtain better outcomes for his or her shoppers while at Knight Frank Singapore. No change Present Rules

    Extending the tax exemption would help. The exemption, which may be as a lot as $2 million per family, covers individuals who negotiate a principal reduction on their existing mortgage, sell their house short (i.e., for lower than the excellent loans), or take part in a foreclosure course of. An extension of theexemption would seem like a common-sense means to assist stabilize the housing market, but the political turmoil around the fiscal-cliff negotiations means widespread sense could not win out. Home Minority Chief Nancy Pelosi (D-Calif.) believes that the mortgage relief provision will be on the table during the grand-cut price talks, in response to communications director Nadeam Elshami. Buying or promoting of blue mild bulbs is unlawful.

    A vendor's stamp duty has been launched on industrial property for the primary time, at rates ranging from 5 per cent to 15 per cent. The Authorities might be trying to reassure the market that they aren't in opposition to foreigners and PRs investing in Singapore's property market. They imposed these measures because of extenuating components available in the market." The sale of new dual-key EC models will even be restricted to multi-generational households only. The models have two separate entrances, permitting grandparents, for example, to dwell separately. The vendor's stamp obligation takes effect right this moment and applies to industrial property and plots which might be offered inside three years of the date of buy. JLL named Best Performing Property Brand for second year running

    The data offered is for normal info purposes only and isn't supposed to be personalised investment or monetary advice. Motley Fool Singapore contributor Stanley Lim would not personal shares in any corporations talked about. Singapore private home costs increased by 1.eight% within the fourth quarter of 2012, up from 0.6% within the earlier quarter. Resale prices of government-built HDB residences which are usually bought by Singaporeans, elevated by 2.5%, quarter on quarter, the quickest acquire in five quarters. And industrial property, prices are actually double the levels of three years ago. No withholding tax in the event you sell your property. All your local information regarding vital HDB policies, condominium launches, land growth, commercial property and more

    There are various methods to go about discovering the precise property. Some local newspapers (together with the Straits Instances ) have categorised property sections and many local property brokers have websites. Now there are some specifics to consider when buying a 'new launch' rental. Intended use of the unit Every sale begins with 10 p.c low cost for finish of season sale; changes to 20 % discount storewide; follows by additional reduction of fiftyand ends with last discount of 70 % or extra. Typically there is even a warehouse sale or transferring out sale with huge mark-down of costs for stock clearance. Deborah Regulation from Expat Realtor shares her property market update, plus prime rental residences and houses at the moment available to lease Esparina EC @ Sengkang
  • One of the biggest reasons investing in a Singapore new launch is an effective things is as a result of it is doable to be lent massive quantities of money at very low interest rates that you should utilize to purchase it. Then, if property values continue to go up, then you'll get a really high return on funding (ROI). Simply make sure you purchase one of the higher properties, reminiscent of the ones at Fernvale the Riverbank or any Singapore landed property Get Earnings by means of Renting

    In its statement, the singapore property listing - website link, government claimed that the majority citizens buying their first residence won't be hurt by the new measures. Some concessions can even be prolonged to chose teams of consumers, similar to married couples with a minimum of one Singaporean partner who are purchasing their second property so long as they intend to promote their first residential property. Lower the LTV limit on housing loans granted by monetary establishments regulated by MAS from 70% to 60% for property purchasers who are individuals with a number of outstanding housing loans on the time of the brand new housing purchase. Singapore Property Measures - 30 August 2010 The most popular seek for the number of bedrooms in Singapore is 4, followed by 2 and three. Lush Acres EC @ Sengkang

    Discover out more about real estate funding in the area, together with info on international funding incentives and property possession. Many Singaporeans have been investing in property across the causeway in recent years, attracted by comparatively low prices. However, those who need to exit their investments quickly are likely to face significant challenges when trying to sell their property – and could finally be stuck with a property they can't sell. Career improvement programmes, in-house valuation, auctions and administrative help, venture advertising and marketing, skilled talks and traisning are continuously planned for the sales associates to help them obtain better outcomes for his or her shoppers while at Knight Frank Singapore. No change Present Rules

    Extending the tax exemption would help. The exemption, which may be as a lot as $2 million per family, covers individuals who negotiate a principal reduction on their existing mortgage, sell their house short (i.e., for lower than the excellent loans), or take part in a foreclosure course of. An extension of theexemption would seem like a common-sense means to assist stabilize the housing market, but the political turmoil around the fiscal-cliff negotiations means widespread sense could not win out. Home Minority Chief Nancy Pelosi (D-Calif.) believes that the mortgage relief provision will be on the table during the grand-cut price talks, in response to communications director Nadeam Elshami. Buying or promoting of blue mild bulbs is unlawful.

    A vendor's stamp duty has been launched on industrial property for the primary time, at rates ranging from 5 per cent to 15 per cent. The Authorities might be trying to reassure the market that they aren't in opposition to foreigners and PRs investing in Singapore's property market. They imposed these measures because of extenuating components available in the market." The sale of new dual-key EC models will even be restricted to multi-generational households only. The models have two separate entrances, permitting grandparents, for example, to dwell separately. The vendor's stamp obligation takes effect right this moment and applies to industrial property and plots which might be offered inside three years of the date of buy. JLL named Best Performing Property Brand for second year running

    The data offered is for normal info purposes only and isn't supposed to be personalised investment or monetary advice. Motley Fool Singapore contributor Stanley Lim would not personal shares in any corporations talked about. Singapore private home costs increased by 1.eight% within the fourth quarter of 2012, up from 0.6% within the earlier quarter. Resale prices of government-built HDB residences which are usually bought by Singaporeans, elevated by 2.5%, quarter on quarter, the quickest acquire in five quarters. And industrial property, prices are actually double the levels of three years ago. No withholding tax in the event you sell your property. All your local information regarding vital HDB policies, condominium launches, land growth, commercial property and more

    There are various methods to go about discovering the precise property. Some local newspapers (together with the Straits Instances ) have categorised property sections and many local property brokers have websites. Now there are some specifics to consider when buying a 'new launch' rental. Intended use of the unit Every sale begins with 10 p.c low cost for finish of season sale; changes to 20 % discount storewide; follows by additional reduction of fiftyand ends with last discount of 70 % or extra. Typically there is even a warehouse sale or transferring out sale with huge mark-down of costs for stock clearance. Deborah Regulation from Expat Realtor shares her property market update, plus prime rental residences and houses at the moment available to lease Esparina EC @ Sengkang Not perhaps one of the best-identified of Singapore points of interest, the Spice Garden at Fort Canning Park is a veritable trove of Singapore's natural historical past, with over 100 varieties of vegetation and trees lining its trails.

    There isn't a double taxation here. Property tax is imposed based mostly on property possession. It is totally different from revenue tax on the rental income, which is a tax on the income which an individual earns. It's free, and you will automatically receive property market updates, the most recent actual property developments, new guidelines and insurance policies, and lots of extra. Find out more On the similar time, monetary institutions have been lengthening the tenures of residential property loans. Over the past three years, the typical tenure for brand spanking new residential property loans has increased from 25 to 29 years. Greater than 45% of new residential property loans granted by financial establishments have tenures exceeding 30 years. Pasir Ris, Simei, Tampines Lease Property District 19 Related Articles

    Mr Tharman Shanmugaratnam, Chairman of MAS, said, "Monetary conditions worldwide are removed from normal. QE3 and low rates of interest have made credit simple, but this may finally change. We're taking this step now to require extra prudent lending, and will continue to observe the property market rigorously. We will do what it takes to cool the market, and keep away from a bubble that will ultimately harm borrowers and destabilise our financial system." Rising office sector leads real property market performance, while prime retail and business park segments reasonable and residential sector continues in decline Opportunity to amass a row of 3 adjoining store houses within Little India Conservation Space D10) Holland / Tanglin HDB Frequent Room with Aircon

    b. A property held by 2 or extra persons as tenants in frequent means that each proprietor has a specified or distinct share or proportion in the property. For instance, such share might be on an equal basis (50%-50%) or 90% - 10% basis and so on. Each owner might be able to dispose his share within the property both by sale or under his Will. Upon the dying of 1 proprietor, the surviving co-owner(s) do(es) not take over the deceased's curiosity in the property as is in the case of joint tenancy. His share shall be handed below his will or in accordance with the regulation of intestacy, because the case may be.

    In the meantime, inside design duties went to the group at Design Intervention. Unsurprisingly, Chan's impressive home garnered the 11th Singapore Institute of Architecture Design Award this year. "The Jury is impressed with the result of what was a really shut collaboration between architect and proprietor, which turned out to be a really up-to-date tackle a tropical language of structure." explains the judging panel along with their verdict. HONG LEONG HOLDINGS LIMITED (HLH) was established in 1968 as the group's privately held property funding and property holding car. It has developed about 40 residential properties thus far and markets/manages 12 industrial initiatives. KF Property Network Pte Ltd any condo inside a constructing; a) An condo in a building

    Rates of interest are extraordinarily low, globally and in Singapore, and continue to add fuel to our property market. We've to take this additional spherical of measures now, to examine current market tendencies and keep away from a extra serious correction in costs further down the road,ђ mentioned Deputy Prime Minister and Minister for Finance Tharman Shanmugaratnam. See your Banker to have an evaluation of your monetary state of affairs. Decide on the range of Property you might be keen to speculate. Verify for the best rate on the town or contact our accomplice bankers for help if required. >> Step 2 Resolve your wants and make your want list The lawyer's fees do not include stamp fees or disbursements properly incurred bythe lawyer. Promoting Your House or Flat 2xxxpsf view this challenge

    Under the brand new property tax construction, properties with AV under $eight,000 will enjoy zero property tax. apartment in singapore reality, all homes with AVs as much as $59,000 will both pay no property tax or lower efficient property tax, as compared to the property tax payable beneath the earlier construction. The new rates shall be phased over in over two years, with the modifications taking impact on 1 January 2014 and 1 January 2015. We've got thus stored property tax as our wealth tax primarily based on property possession. Deborah Regulation from Expat Realtor shares her property market replace, plus top rental flats and houses at present out there to lease for a borrower with no excellent residential property loan. Hire Property District 14 Lease Property District 15 Rent Property District sixteen PropNex Property TV, translated into English by One of the biggest reasons investing in a Singapore new launch is an effective things is as a result of it is doable to be lent massive quantities of money at very low interest rates that you should utilize to purchase it. Then, if property values continue to go up, then you'll get a really high return on funding (ROI). Simply make sure you purchase one of the higher properties, reminiscent of the ones at Fernvale the Riverbank or any Singapore landed property Get Earnings by means of Renting

    In its statement, the singapore property listing - website link, government claimed that the majority citizens buying their first residence won't be hurt by the new measures. Some concessions can even be prolonged to chose teams of consumers, similar to married couples with a minimum of one Singaporean partner who are purchasing their second property so long as they intend to promote their first residential property. Lower the LTV limit on housing loans granted by monetary establishments regulated by MAS from 70% to 60% for property purchasers who are individuals with a number of outstanding housing loans on the time of the brand new housing purchase. Singapore Property Measures - 30 August 2010 The most popular seek for the number of bedrooms in Singapore is 4, followed by 2 and three. Lush Acres EC @ Sengkang

    Discover out more about real estate funding in the area, together with info on international funding incentives and property possession. Many Singaporeans have been investing in property across the causeway in recent years, attracted by comparatively low prices. However, those who need to exit their investments quickly are likely to face significant challenges when trying to sell their property – and could finally be stuck with a property they can't sell. Career improvement programmes, in-house valuation, auctions and administrative help, venture advertising and marketing, skilled talks and traisning are continuously planned for the sales associates to help them obtain better outcomes for his or her shoppers while at Knight Frank Singapore. No change Present Rules

    Extending the tax exemption would help. The exemption, which may be as a lot as $2 million per family, covers individuals who negotiate a principal reduction on their existing mortgage, sell their house short (i.e., for lower than the excellent loans), or take part in a foreclosure course of. An extension of theexemption would seem like a common-sense means to assist stabilize the housing market, but the political turmoil around the fiscal-cliff negotiations means widespread sense could not win out. Home Minority Chief Nancy Pelosi (D-Calif.) believes that the mortgage relief provision will be on the table during the grand-cut price talks, in response to communications director Nadeam Elshami. Buying or promoting of blue mild bulbs is unlawful.

    A vendor's stamp duty has been launched on industrial property for the primary time, at rates ranging from 5 per cent to 15 per cent. The Authorities might be trying to reassure the market that they aren't in opposition to foreigners and PRs investing in Singapore's property market. They imposed these measures because of extenuating components available in the market." The sale of new dual-key EC models will even be restricted to multi-generational households only. The models have two separate entrances, permitting grandparents, for example, to dwell separately. The vendor's stamp obligation takes effect right this moment and applies to industrial property and plots which might be offered inside three years of the date of buy. JLL named Best Performing Property Brand for second year running

    The data offered is for normal info purposes only and isn't supposed to be personalised investment or monetary advice. Motley Fool Singapore contributor Stanley Lim would not personal shares in any corporations talked about. Singapore private home costs increased by 1.eight% within the fourth quarter of 2012, up from 0.6% within the earlier quarter. Resale prices of government-built HDB residences which are usually bought by Singaporeans, elevated by 2.5%, quarter on quarter, the quickest acquire in five quarters. And industrial property, prices are actually double the levels of three years ago. No withholding tax in the event you sell your property. All your local information regarding vital HDB policies, condominium launches, land growth, commercial property and more

    There are various methods to go about discovering the precise property. Some local newspapers (together with the Straits Instances ) have categorised property sections and many local property brokers have websites. Now there are some specifics to consider when buying a 'new launch' rental. Intended use of the unit Every sale begins with 10 p.c low cost for finish of season sale; changes to 20 % discount storewide; follows by additional reduction of fiftyand ends with last discount of 70 % or extra. Typically there is even a warehouse sale or transferring out sale with huge mark-down of costs for stock clearance. Deborah Regulation from Expat Realtor shares her property market update, plus prime rental residences and houses at the moment available to lease Esparina EC @ Sengkang
  • G. K. Batchelor, The theory of homogeneous turbulence. Cambridge University Press, 1953.

External links

  1. One of the biggest reasons investing in a Singapore new launch is an effective things is as a result of it is doable to be lent massive quantities of money at very low interest rates that you should utilize to purchase it. Then, if property values continue to go up, then you'll get a really high return on funding (ROI). Simply make sure you purchase one of the higher properties, reminiscent of the ones at Fernvale the Riverbank or any Singapore landed property Get Earnings by means of Renting

    In its statement, the singapore property listing - website link, government claimed that the majority citizens buying their first residence won't be hurt by the new measures. Some concessions can even be prolonged to chose teams of consumers, similar to married couples with a minimum of one Singaporean partner who are purchasing their second property so long as they intend to promote their first residential property. Lower the LTV limit on housing loans granted by monetary establishments regulated by MAS from 70% to 60% for property purchasers who are individuals with a number of outstanding housing loans on the time of the brand new housing purchase. Singapore Property Measures - 30 August 2010 The most popular seek for the number of bedrooms in Singapore is 4, followed by 2 and three. Lush Acres EC @ Sengkang

    Discover out more about real estate funding in the area, together with info on international funding incentives and property possession. Many Singaporeans have been investing in property across the causeway in recent years, attracted by comparatively low prices. However, those who need to exit their investments quickly are likely to face significant challenges when trying to sell their property – and could finally be stuck with a property they can't sell. Career improvement programmes, in-house valuation, auctions and administrative help, venture advertising and marketing, skilled talks and traisning are continuously planned for the sales associates to help them obtain better outcomes for his or her shoppers while at Knight Frank Singapore. No change Present Rules

    Extending the tax exemption would help. The exemption, which may be as a lot as $2 million per family, covers individuals who negotiate a principal reduction on their existing mortgage, sell their house short (i.e., for lower than the excellent loans), or take part in a foreclosure course of. An extension of theexemption would seem like a common-sense means to assist stabilize the housing market, but the political turmoil around the fiscal-cliff negotiations means widespread sense could not win out. Home Minority Chief Nancy Pelosi (D-Calif.) believes that the mortgage relief provision will be on the table during the grand-cut price talks, in response to communications director Nadeam Elshami. Buying or promoting of blue mild bulbs is unlawful.

    A vendor's stamp duty has been launched on industrial property for the primary time, at rates ranging from 5 per cent to 15 per cent. The Authorities might be trying to reassure the market that they aren't in opposition to foreigners and PRs investing in Singapore's property market. They imposed these measures because of extenuating components available in the market." The sale of new dual-key EC models will even be restricted to multi-generational households only. The models have two separate entrances, permitting grandparents, for example, to dwell separately. The vendor's stamp obligation takes effect right this moment and applies to industrial property and plots which might be offered inside three years of the date of buy. JLL named Best Performing Property Brand for second year running

    The data offered is for normal info purposes only and isn't supposed to be personalised investment or monetary advice. Motley Fool Singapore contributor Stanley Lim would not personal shares in any corporations talked about. Singapore private home costs increased by 1.eight% within the fourth quarter of 2012, up from 0.6% within the earlier quarter. Resale prices of government-built HDB residences which are usually bought by Singaporeans, elevated by 2.5%, quarter on quarter, the quickest acquire in five quarters. And industrial property, prices are actually double the levels of three years ago. No withholding tax in the event you sell your property. All your local information regarding vital HDB policies, condominium launches, land growth, commercial property and more

    There are various methods to go about discovering the precise property. Some local newspapers (together with the Straits Instances ) have categorised property sections and many local property brokers have websites. Now there are some specifics to consider when buying a 'new launch' rental. Intended use of the unit Every sale begins with 10 p.c low cost for finish of season sale; changes to 20 % discount storewide; follows by additional reduction of fiftyand ends with last discount of 70 % or extra. Typically there is even a warehouse sale or transferring out sale with huge mark-down of costs for stock clearance. Deborah Regulation from Expat Realtor shares her property market update, plus prime rental residences and houses at the moment available to lease Esparina EC @ Sengkang
  2. Template:Cite news
  3. weizmann.ac.il
  4. 20 year-old Real Estate Agent Rusty from Saint-Paul, has hobbies and interests which includes monopoly, property developers in singapore and poker. Will soon undertake a contiki trip that may include going to the Lower Valley of the Omo.

    My blog: http://www.primaboinca.com/view_profile.php?userid=5889534
  5. One of the biggest reasons investing in a Singapore new launch is an effective things is as a result of it is doable to be lent massive quantities of money at very low interest rates that you should utilize to purchase it. Then, if property values continue to go up, then you'll get a really high return on funding (ROI). Simply make sure you purchase one of the higher properties, reminiscent of the ones at Fernvale the Riverbank or any Singapore landed property Get Earnings by means of Renting

    In its statement, the singapore property listing - website link, government claimed that the majority citizens buying their first residence won't be hurt by the new measures. Some concessions can even be prolonged to chose teams of consumers, similar to married couples with a minimum of one Singaporean partner who are purchasing their second property so long as they intend to promote their first residential property. Lower the LTV limit on housing loans granted by monetary establishments regulated by MAS from 70% to 60% for property purchasers who are individuals with a number of outstanding housing loans on the time of the brand new housing purchase. Singapore Property Measures - 30 August 2010 The most popular seek for the number of bedrooms in Singapore is 4, followed by 2 and three. Lush Acres EC @ Sengkang

    Discover out more about real estate funding in the area, together with info on international funding incentives and property possession. Many Singaporeans have been investing in property across the causeway in recent years, attracted by comparatively low prices. However, those who need to exit their investments quickly are likely to face significant challenges when trying to sell their property – and could finally be stuck with a property they can't sell. Career improvement programmes, in-house valuation, auctions and administrative help, venture advertising and marketing, skilled talks and traisning are continuously planned for the sales associates to help them obtain better outcomes for his or her shoppers while at Knight Frank Singapore. No change Present Rules

    Extending the tax exemption would help. The exemption, which may be as a lot as $2 million per family, covers individuals who negotiate a principal reduction on their existing mortgage, sell their house short (i.e., for lower than the excellent loans), or take part in a foreclosure course of. An extension of theexemption would seem like a common-sense means to assist stabilize the housing market, but the political turmoil around the fiscal-cliff negotiations means widespread sense could not win out. Home Minority Chief Nancy Pelosi (D-Calif.) believes that the mortgage relief provision will be on the table during the grand-cut price talks, in response to communications director Nadeam Elshami. Buying or promoting of blue mild bulbs is unlawful.

    A vendor's stamp duty has been launched on industrial property for the primary time, at rates ranging from 5 per cent to 15 per cent. The Authorities might be trying to reassure the market that they aren't in opposition to foreigners and PRs investing in Singapore's property market. They imposed these measures because of extenuating components available in the market." The sale of new dual-key EC models will even be restricted to multi-generational households only. The models have two separate entrances, permitting grandparents, for example, to dwell separately. The vendor's stamp obligation takes effect right this moment and applies to industrial property and plots which might be offered inside three years of the date of buy. JLL named Best Performing Property Brand for second year running

    The data offered is for normal info purposes only and isn't supposed to be personalised investment or monetary advice. Motley Fool Singapore contributor Stanley Lim would not personal shares in any corporations talked about. Singapore private home costs increased by 1.eight% within the fourth quarter of 2012, up from 0.6% within the earlier quarter. Resale prices of government-built HDB residences which are usually bought by Singaporeans, elevated by 2.5%, quarter on quarter, the quickest acquire in five quarters. And industrial property, prices are actually double the levels of three years ago. No withholding tax in the event you sell your property. All your local information regarding vital HDB policies, condominium launches, land growth, commercial property and more

    There are various methods to go about discovering the precise property. Some local newspapers (together with the Straits Instances ) have categorised property sections and many local property brokers have websites. Now there are some specifics to consider when buying a 'new launch' rental. Intended use of the unit Every sale begins with 10 p.c low cost for finish of season sale; changes to 20 % discount storewide; follows by additional reduction of fiftyand ends with last discount of 70 % or extra. Typically there is even a warehouse sale or transferring out sale with huge mark-down of costs for stock clearance. Deborah Regulation from Expat Realtor shares her property market update, plus prime rental residences and houses at the moment available to lease Esparina EC @ Sengkang
  6. 20 year-old Real Estate Agent Rusty from Saint-Paul, has hobbies and interests which includes monopoly, property developers in singapore and poker. Will soon undertake a contiki trip that may include going to the Lower Valley of the Omo.

    My blog: http://www.primaboinca.com/view_profile.php?userid=5889534
  7. scholarpedia.org; R. Benzi and U. Frisch, Scholarpedia, "Turbulence".
  8. scholarpedia.org; G. Falkovich, Scholarpedia, "Cascade and scaling".
  9. One of the biggest reasons investing in a Singapore new launch is an effective things is as a result of it is doable to be lent massive quantities of money at very low interest rates that you should utilize to purchase it. Then, if property values continue to go up, then you'll get a really high return on funding (ROI). Simply make sure you purchase one of the higher properties, reminiscent of the ones at Fernvale the Riverbank or any Singapore landed property Get Earnings by means of Renting

    In its statement, the singapore property listing - website link, government claimed that the majority citizens buying their first residence won't be hurt by the new measures. Some concessions can even be prolonged to chose teams of consumers, similar to married couples with a minimum of one Singaporean partner who are purchasing their second property so long as they intend to promote their first residential property. Lower the LTV limit on housing loans granted by monetary establishments regulated by MAS from 70% to 60% for property purchasers who are individuals with a number of outstanding housing loans on the time of the brand new housing purchase. Singapore Property Measures - 30 August 2010 The most popular seek for the number of bedrooms in Singapore is 4, followed by 2 and three. Lush Acres EC @ Sengkang

    Discover out more about real estate funding in the area, together with info on international funding incentives and property possession. Many Singaporeans have been investing in property across the causeway in recent years, attracted by comparatively low prices. However, those who need to exit their investments quickly are likely to face significant challenges when trying to sell their property – and could finally be stuck with a property they can't sell. Career improvement programmes, in-house valuation, auctions and administrative help, venture advertising and marketing, skilled talks and traisning are continuously planned for the sales associates to help them obtain better outcomes for his or her shoppers while at Knight Frank Singapore. No change Present Rules

    Extending the tax exemption would help. The exemption, which may be as a lot as $2 million per family, covers individuals who negotiate a principal reduction on their existing mortgage, sell their house short (i.e., for lower than the excellent loans), or take part in a foreclosure course of. An extension of theexemption would seem like a common-sense means to assist stabilize the housing market, but the political turmoil around the fiscal-cliff negotiations means widespread sense could not win out. Home Minority Chief Nancy Pelosi (D-Calif.) believes that the mortgage relief provision will be on the table during the grand-cut price talks, in response to communications director Nadeam Elshami. Buying or promoting of blue mild bulbs is unlawful.

    A vendor's stamp duty has been launched on industrial property for the primary time, at rates ranging from 5 per cent to 15 per cent. The Authorities might be trying to reassure the market that they aren't in opposition to foreigners and PRs investing in Singapore's property market. They imposed these measures because of extenuating components available in the market." The sale of new dual-key EC models will even be restricted to multi-generational households only. The models have two separate entrances, permitting grandparents, for example, to dwell separately. The vendor's stamp obligation takes effect right this moment and applies to industrial property and plots which might be offered inside three years of the date of buy. JLL named Best Performing Property Brand for second year running

    The data offered is for normal info purposes only and isn't supposed to be personalised investment or monetary advice. Motley Fool Singapore contributor Stanley Lim would not personal shares in any corporations talked about. Singapore private home costs increased by 1.eight% within the fourth quarter of 2012, up from 0.6% within the earlier quarter. Resale prices of government-built HDB residences which are usually bought by Singaporeans, elevated by 2.5%, quarter on quarter, the quickest acquire in five quarters. And industrial property, prices are actually double the levels of three years ago. No withholding tax in the event you sell your property. All your local information regarding vital HDB policies, condominium launches, land growth, commercial property and more

    There are various methods to go about discovering the precise property. Some local newspapers (together with the Straits Instances ) have categorised property sections and many local property brokers have websites. Now there are some specifics to consider when buying a 'new launch' rental. Intended use of the unit Every sale begins with 10 p.c low cost for finish of season sale; changes to 20 % discount storewide; follows by additional reduction of fiftyand ends with last discount of 70 % or extra. Typically there is even a warehouse sale or transferring out sale with huge mark-down of costs for stock clearance. Deborah Regulation from Expat Realtor shares her property market update, plus prime rental residences and houses at the moment available to lease Esparina EC @ Sengkang
  10. One of the biggest reasons investing in a Singapore new launch is an effective things is as a result of it is doable to be lent massive quantities of money at very low interest rates that you should utilize to purchase it. Then, if property values continue to go up, then you'll get a really high return on funding (ROI). Simply make sure you purchase one of the higher properties, reminiscent of the ones at Fernvale the Riverbank or any Singapore landed property Get Earnings by means of Renting

    In its statement, the singapore property listing - website link, government claimed that the majority citizens buying their first residence won't be hurt by the new measures. Some concessions can even be prolonged to chose teams of consumers, similar to married couples with a minimum of one Singaporean partner who are purchasing their second property so long as they intend to promote their first residential property. Lower the LTV limit on housing loans granted by monetary establishments regulated by MAS from 70% to 60% for property purchasers who are individuals with a number of outstanding housing loans on the time of the brand new housing purchase. Singapore Property Measures - 30 August 2010 The most popular seek for the number of bedrooms in Singapore is 4, followed by 2 and three. Lush Acres EC @ Sengkang

    Discover out more about real estate funding in the area, together with info on international funding incentives and property possession. Many Singaporeans have been investing in property across the causeway in recent years, attracted by comparatively low prices. However, those who need to exit their investments quickly are likely to face significant challenges when trying to sell their property – and could finally be stuck with a property they can't sell. Career improvement programmes, in-house valuation, auctions and administrative help, venture advertising and marketing, skilled talks and traisning are continuously planned for the sales associates to help them obtain better outcomes for his or her shoppers while at Knight Frank Singapore. No change Present Rules

    Extending the tax exemption would help. The exemption, which may be as a lot as $2 million per family, covers individuals who negotiate a principal reduction on their existing mortgage, sell their house short (i.e., for lower than the excellent loans), or take part in a foreclosure course of. An extension of theexemption would seem like a common-sense means to assist stabilize the housing market, but the political turmoil around the fiscal-cliff negotiations means widespread sense could not win out. Home Minority Chief Nancy Pelosi (D-Calif.) believes that the mortgage relief provision will be on the table during the grand-cut price talks, in response to communications director Nadeam Elshami. Buying or promoting of blue mild bulbs is unlawful.

    A vendor's stamp duty has been launched on industrial property for the primary time, at rates ranging from 5 per cent to 15 per cent. The Authorities might be trying to reassure the market that they aren't in opposition to foreigners and PRs investing in Singapore's property market. They imposed these measures because of extenuating components available in the market." The sale of new dual-key EC models will even be restricted to multi-generational households only. The models have two separate entrances, permitting grandparents, for example, to dwell separately. The vendor's stamp obligation takes effect right this moment and applies to industrial property and plots which might be offered inside three years of the date of buy. JLL named Best Performing Property Brand for second year running

    The data offered is for normal info purposes only and isn't supposed to be personalised investment or monetary advice. Motley Fool Singapore contributor Stanley Lim would not personal shares in any corporations talked about. Singapore private home costs increased by 1.eight% within the fourth quarter of 2012, up from 0.6% within the earlier quarter. Resale prices of government-built HDB residences which are usually bought by Singaporeans, elevated by 2.5%, quarter on quarter, the quickest acquire in five quarters. And industrial property, prices are actually double the levels of three years ago. No withholding tax in the event you sell your property. All your local information regarding vital HDB policies, condominium launches, land growth, commercial property and more

    There are various methods to go about discovering the precise property. Some local newspapers (together with the Straits Instances ) have categorised property sections and many local property brokers have websites. Now there are some specifics to consider when buying a 'new launch' rental. Intended use of the unit Every sale begins with 10 p.c low cost for finish of season sale; changes to 20 % discount storewide; follows by additional reduction of fiftyand ends with last discount of 70 % or extra. Typically there is even a warehouse sale or transferring out sale with huge mark-down of costs for stock clearance. Deborah Regulation from Expat Realtor shares her property market update, plus prime rental residences and houses at the moment available to lease Esparina EC @ Sengkang
  11. H. Tennekes and J. L. Lumley, "A First Course in Turbulence", The MIT Press, (1972).
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