Home Books eBooks Journals References & Proceedings Authors, Editors, Reviewers A-Z Product Index Awards
Turbulence and Shear Flow Phenomena -1 First International Symposium

ISBN:
1-56700-135-1 (Print)

APPLICATION OF NON-LINEAR EDDY-VISCOSITY AND DIFFERENTIAL STRESS CLOSURES TO SEPARATED FLOW

David D. Apsley
School of Mechanical, Aerospace and Civil Engineering, University of Manchester Manchester, United Kingdom, M60 1QD

Michael A. Leschziner
Aeronautics Department, Imperial College London, Prince Consort Rd., London SW7 2AZ, United Kingdom

Abstract

Non-linear eddy-viscosity models and second-moment closure are examined, both theoretically and by comparison with 2-d and 3-d test cases featuring separation from mildly curved surfaces. It is found that, whereas non-linear stress-strain relations improve the prediction of normal-stress anisotropy, the mean flow dynamics are primarily influenced by the shear stress and, in particular, by the use of a strain-dependent linear coefficient. The advantages of second-moment closure are most apparent in fully 3-d flows, where several stress components are important. Determination of the turbulent length scale remains a crucial element in the performance of models in non-equilibrium flows.