Accession Number : ADA188339

Title :   Coherent Structure-Reflective Turbulent Viscous Flow Modeling.

Descriptive Note : Final rept. Mar 85-Mar 87,

Corporate Author : HOKENSON CO LOS ANGELES CA

Personal Author(s) : Hokenson, Gustave J

PDF Url : ADA188339

Report Date : 07 Sep 1987

Pagination or Media Count : 94

Abstract : Three aspects of turbulent structure in shear flows were investigated theoretically. Both analytical and computational strategies were employed to extract new information on: 1) advection velocities of large-scale structure; 2) the velocity vector angle characteristics of turbulent fluctuations; and 3) the 'stability' characteristics of the mean turbulent velocity profile. With regard to topic1, the study of the propagation of a bulge in wall-bounded shear flow has exposed three characteristic propagation speeds. In (temporally and/or spatially) variable pressure flows, a unique inverse approach to the problem has exposed the critical value for the shape factor (H) of 2.0. This result impacts not only turbulent structure dynamics but flowfield separation as well. The work on topic 2, has served to clarify the importance of angular structure with respect to the interpretations of turbulence physics, the modeling thereof and advantages of those variables in numerical simulation. Finally, the mean turbulent velocity profile was found to support unstable modes of oscillation for the large-scale structure if the unresolved small scale processes are modeled appropriately. Keywords: Turbulent Viscous flow.

Descriptors :   *FLOW SEPARATION, *TURBULENT FLOW, *VISCOUS FLOW, ADVECTION, ANGLES, COMPUTATIONS, DYNAMICS, UNSTEADY FLOW, FLOW FIELDS, INVERSION, MEAN, NUMERICAL ANALYSIS, OSCILLATION, PROFILES, PROPAGATION, SHAPE, STRATEGY, STRUCTURAL PROPERTIES, TURBULENCE, VARIABLE PRESSURE, VARIATIONS, VECTOR ANALYSIS, VELOCITY, COHERENCE, MATHEMATICAL MODELS, TURBULENT BOUNDARY LAYER, FREE STREAM

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE