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 flows 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 dynamic WALE 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.
Keywords
- Large-eddy simulation
- Quality
- Dynamic WALE model
- Grid irregularity