Library Subscription: Guest
TSFP DL Home Archives Executive Committee

MODELLING 2D AND 3D SEPARATION FROM CURVED SURFACES WITH ANISOTROPY-RESOLVING TURBULENCE CLOSURES

C. Wang
Department of Aeronautics, Imperial College London, South Kensington, London SW7 2AZ, UK

Y.J. Jang
Department of Aeronautics, Imperial College London, South Kensington, London SW7 2AZ, UK

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

Abstract

The ability of non-linear eddy-viscosity and second-moment models to predict separation from two-and three-dimensional curved surfaces is examined by reference to two flows that are geometrically akin: one separating from periodically-spaced two-dimensional 'hills' in a plane channel, and the other from a three-dimensional hill in a duct. One major objective is to examine whether the predictive performance in 3-d conditions relates to that in 2d flow. In the former, the separation pattern is far more complicated, being characterised by multiple vortical structures associated with 'open' separation. The predicted separation behaviour in the 2-d flow differs significantly from model to model, with only one non-linear model among those examined performing well, this variant formulated to adhere to the two-component wall limit. In 3-d separation, none of the models gives a credible representation of the complex multi-vortical separation pattern.