18th Symposium on Boundary Layers and Turbulence

10B.7

A posteriori subgrid-scale model tests based on the conditional means of subgrid-scale stress and its production rate

Qinglin Chen, Clemson University, Clemson, SC; and M. J. Otte, P. P. Sullivan, and C. Tong

Traditional a posteriori tests of subgrid-scale (SGS) models often compare large eddy simulation (LES) profiles of various statistics with measurements. In this study we propose and employ a new a posteriori test to study SGS model performance. We compare the conditional means of the LES-generated SGS stress and stress production rate conditional on the resolvable-scale velocity with measurements. These statistics must be reproduced by the SGS model for LES to correctly predict the one-point resolvable-scale velocity joint probability density function. The tests using data for convective atmospheric boundary layers show that the a posteriori results are consistent with our a priori tests based on the same conditional statistics. The model strengths and deficiencies observed here were also identified in our a priori tests. The remarkable consistency between the two types of tests suggests that statistical model tests based on the conditional SGS stress and its production rate are a highly capable approach for identifying specific model deficiencies and for evaluating SGS model performance in simulations.

extended abstract  Extended Abstract (356K)

Session 10B, LARGE EDDY SIMULATIONS AND FUNDAMENTAL STUDIES—II
Wednesday, 11 June 2008, 10:30 AM-12:30 PM, Aula Magna Höger

Previous paper  Next paper

Browse or search entire meeting

AMS Home Page