Coherent structure ramp models for structure functions of temperature in turbulent shear flows
Abstract
The ramp model originally developed for coherent structures in atmospheric boundary layers can give only mean values for the ramp amplitude and repetition period, which are found to be not extremely sensitive to the choice of probability density for the amplitude. The discussion covers the behavior of temperature structure functions in various flows, the effect of different probability densities, and the criteria for determining the mean ramp length. The results indicate that the ramp model will not yield misleading results for cases with no coherent ramp structure. Consideration of the variation of the mean length of the quiescent period (between successive ramps) with ramp length gives useful bounds on allowable values of these two parameters.
 Publication:

Structure and Mechanisms of Turbulence I
 Pub Date:
 1978
 Bibcode:
 1978LNP....75..138V
 Keywords:

 Atmospheric Boundary Layer;
 Mathematical Models;
 Ramp Functions;
 Shear Flow;
 Temperature Distribution;
 Turbulent Boundary Layer;
 Atmospheric Temperature;
 Coherence;
 Probability Density Functions;
 Thermal Boundary Layer;
 Turbulent Jets;
 Fluid Mechanics and Heat Transfer