Possibilities of Incorporating Coherent Structure Models in Turbulent Shear Flow Calculations

1990 ◽  
Vol 43 (5S) ◽  
pp. S210-S213
Author(s):  
J. T. C. Liu
Keyword(s):  
Shear Flow ◽  
Coherent Structure ◽  
Shear Flows ◽  
Hydrodynamic Instability ◽  
Turbulent Shear ◽  
Turbulent Shear Flow ◽  
Wall Bounded Flows ◽  
Dynamical Instabilities

We discuss possibilities of using coherent structure models in turbulent shear flow description. The nonuniversality of different classes of such flows is directly attributed to the nonuniversality of hydrodynamic instability mechanisms. This is fully explored in discussions of free shear flows, where dynamical instabilities are important and in wall-bounded flows where longitudinal vorticity system and its nonlinear consequence are at play.

On the structure of pressure fluctuations in turbulent shear flow

1975 ◽  
Vol 71 (4) ◽  
pp. 801-813 ◽  
Author(s):  
P. J. Mulhearn
Keyword(s):  
Shear Flow ◽  
Qualitative Agreement ◽  
Shear Flows ◽  
Pressure Fluctuations ◽  
Turbulent Shear ◽  
Turbulent Shear Flow ◽  
Velocity Fluctuations ◽  
Uniform Shear ◽  
Uniform Shear Flow ◽  
Highly Correlated

Pressure and pressure-velocity space correlations are calculated, using rapid-distortion theory, for turbulence in a uniform shear flow. It is found that pressure fluctuations remain correlated over significantly greater distances than do velocity fluctuations. When these predictions are used as a model for turbulence in free turbulent shear flows, it is found that the predicted scale of the pressure fluctuations is larger than the flow width. It is proposed that pressure fluctuations remain highly correlated right across free shear flows. Predictions from the theory are then compared with various experimental situations in which reasonable qualitative agreement is to be expected, and this is found.

Identification of Coherent Structure in Turbulent Shear Flow With Wavelet Correlation Analysis

1998 ◽  
Vol 120 (4) ◽  
pp. 778-785 ◽  
Author(s):  
Hui Li
Keyword(s):  
Correlation Analysis ◽  
Shear Flow ◽  
Coherent Structure ◽  
Correlation Method ◽  
New Combination ◽  
Turbulent Shear ◽  
Two Dimensional ◽  
Turbulent Shear Flow ◽  
Structure Information ◽  
Time Period

In order to identify coherent structure of turbulent shear flow, a new combination of familiar techniques of signal processing, called wavelet correlation analysis, is developed based on the wavelet transform. The wavelet correlation analysis provides the unique capability for decomposing the correlation of arbitrary signals over a two-dimensional time delay-period plane. By analyzing two superposition functions implicating several pure frequencies, the correlation of periodic oscillations at several frequencies can well be separated and observed clearly. Coherent structures in the intermediate region of a plane turbulent jet are investigated using the wavelet correlation method. It is shown that the wavelet correlation analysis can extract the most essential scales governing features of eddy motions. The coherent structure information and apparent flapping behaviors are clearly revealed over a two-dimensional time-period plane.

Open-loop control of compensation for optical propagation through a turbulent shear flow

1998 ◽  
Author(s):  
C. Truman ◽  
Lenore McMackin ◽  
Robert Pierson ◽  
Kenneth Bishop ◽  
Ellen Chen
Keyword(s):  
Shear Flow ◽  
Open Loop ◽  
Turbulent Shear ◽  
Turbulent Shear Flow ◽  
Open Loop Control ◽  
Loop Control ◽  
Optical Propagation

scholarly journals Scale dependence of the alignment between strain rate and rotation in turbulent shear flow

2016 ◽  
Vol 1 (6) ◽  
Author(s):  
D. Fiscaletti ◽  
G. E. Elsinga ◽  
A. Attili ◽  
F. Bisetti ◽  
O. R. H. Buxton
Keyword(s):  
Shear Flow ◽  
Strain Rate ◽  
Scale Dependence ◽  
Turbulent Shear ◽  
Turbulent Shear Flow

The structure of turbulent shear flow

1980 ◽  
Vol 70 (1-2) ◽  
pp. 187-188
Author(s):  
F.H. Busse
Keyword(s):  
Shear Flow ◽  
Turbulent Shear ◽  
Turbulent Shear Flow

Effects of turbulent shear flow on zooplankton distribution

1990 ◽  
Vol 37 (3) ◽  
pp. 447-461 ◽  
Author(s):  
Loren R. Haury ◽  
Hidekatsu Yamazaki ◽  
Eric C. Itsweire
Keyword(s):  
Shear Flow ◽  
Turbulent Shear ◽  
Turbulent Shear Flow ◽  
Zooplankton Distribution

scholarly journals MAGNETIC RESONANCE SIGNAL LOSS IN TURBULENT SHEAR FLOW

2002 ◽  
Vol 14 (01) ◽  
pp. 1-11
Author(s):  
LIANG-DER JOU
Keyword(s):  
Shear Flow ◽  
Velocity Fluctuation ◽  
Phase Fluctuation ◽  
Eddy Diffusivity ◽  
Turbulent Shear ◽  
Turbulent Shear Flow ◽  
Signal Loss ◽  
Flow Shear ◽  
Magnetic Gradient ◽  
Spin Echo Sequence

NMR signal loss due to turbulent shear flow is discussed, and a general expression for the phase fluctuation is derived. In the presence of flow shear, the velocity fluctuation perpendicular to the direction of magnetic gradient and the Reynolds stress can cause loss of MR signal Most of signal loss results from the boundary layer, where the flow shear is strong in turbulent pipe flaw, Half the signal loss within the mixing layer distal to a moderate stenosis is caused by the velocity fluctuation in the direction of magnetic gradient, while the remaining results from the velocity, fluctuation perpendicular to the magnetic gradient. The use of eddy diffusivity for the description of signal dephasing in a spin echo sequence is also addressed; A positive, constant eddy diffusivity can not describe the temporal change of phase fluctuation correctly.

Sign in / Sign up

Export Citation Format

Share Document