Accession Number : ADA299613

Title :   Structure-Based Turbulence Model.

Descriptive Note : Final rept. 1 Apr 91-31 Jan 95,

Corporate Author : STANFORD UNIV CA DEPT OF MECHANICAL ENGINEERING

Personal Author(s) : Reynolds, W. C.

PDF Url : ADA299613

Report Date : 24 MAY 1995

Pagination or Media Count : 8

Abstract : Models of turbulence for complex engineering flows need to be able to span the full range of deformation rates from slow, where eddy viscosity models (e.g.k-e) relating the turbulent stress to the mean strain rate are valid, to rapid deformations where the stresses are determined by the amount of strain. In order to build a one-point turbulence model that can match Rapid Distortion Theory (RDT) when appropriate, new concepts are needed to parameterize the turbulence structure. This research, which builds upon these new concepts, develops a new structure-based model for RDT of homogeneous turbulence that will be used as the backbone of a more general model for both slow and rapid distortion in general turbulent flows. The model has been tested against exact IQDT for a very wide variety flows involving various complex combinations of mean strain and rotation. Adequate agreement is found in all cases and excellent agreement in most. The work is a key step towards a more general, robust engineering model for predicting turbulent flows.

Descriptors :   *MATHEMATICAL MODELS, *TURBULENT FLOW, *DISTORTION, STRESS STRAIN RELATIONS, TWO DIMENSIONAL, DEFORMATION, BOUNDARY LAYER, TURBULENCE, EDDIES(FLUID MECHANICS), VORTICES, FLOW FIELDS, SHEAR STRESSES, VISCOSITY, REYNOLDS NUMBER, INCOMPRESSIBLE FLOW, HOMOGENEITY, SHEAR FLOW, AXIAL FLOW, AXISYMMETRIC FLOW.

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE