Study of the effect of grid irregularity on the quality of LES simulations

The present paper investigates the effect of grid irregularity on the results of
large eddy simulations in turbulent channel flow at Re = 180. Having the error components
involved in LES, the grid irregularity effect on the shortcoming of the subgrid scale models
and the error of numerical approximation is also assessed. A dynamic version of the WALE
model for variable density fows and the variational multi-scale type model based on the
dynamic WALE instead of the classical Smagorinsky are implemented. One regular grid
and three different disturbed grids are considered. The dynamicWALE model and its VMS
version are assessed and compared to the DNS data and to the results obtained from the
dynamic Smagorisky model for the three grids. Comparison has shown that the models
improve the quality of LES results. It was also noticed that these models, as compared
with the dynamic Smagorinsky model, are less affected by grid distortion.