LES prediction of space-time correlations in turbulent shear flows
نویسندگان
چکیده
منابع مشابه
Space-time correlations of fluctuating velocities in turbulent shear flows.
Space-time correlations or Eulerian two-point two-time correlations of fluctuating velocities are analytically and numerically investigated in turbulent shear flows. An elliptic model for the space-time correlations in the inertial range is developed from the similarity assumptions on the isocorrelation contours: they share a uniform preference direction and a constant aspect ratio. The similar...
متن کاملElliptic model for space-time correlations in turbulent shear flows.
An elliptic model for space-time correlations in turbulent shear flows is proposed based on a second order approximation to the iso-correlation contours, while Taylor's hypothesis implies a first-order approximation. It is shown that the space-time correlations are mainly determined by their space correlations and the convection and sweeping velocities. This model accommodates two extreme cases...
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We investigate spatial and temporal cross-correlations between streamwise and normal velocity components in three shear flows: a low-dimensional model for vortex-streak interactions, direct numerical simulations for a nearly homogeneous shear flow and experimental data for a turbulent boundary layer. A driving of streamwise streaks by streamwise vortices gives rise to a temporal asymmetry in th...
متن کاملOverview of turbulent shear flows
A brief review of basic concepts and folklore in shear turbulence. 1 Reynolds decomposition Experimental measurements show that turbulent flows can be decomposed into welldefined averages plus fluctuations, v = v̄ + v′. This is nicely illustrated in the Turbulence film available online at http://web.mit.edu/hml/ncfmf.html that was already mentioned in Lecture 1. In experiments, the average v̄ is ...
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We consider the effects of a shear on velocity fluctuations in a flow. The shear gives rise to a transient amplification that not only influences the amplitude of perturbations but also their time correlations. We show that, in the presence of white noise, time correlations of transversal velocity components are exponential and that correlations of the longitudinal components are exponential wi...
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ژورنال
عنوان ژورنال: Acta Mechanica Sinica
سال: 2012
ISSN: 0567-7718,1614-3116
DOI: 10.1007/s10409-012-0088-5