Grid resolution assessment in large eddy simulation of dispersion around an isolated cubic building

In the present paper, the influence of grid resolution on prediction accuracy of large eddy simulation (LES) of dispersion around an isolated cubic building was investigated. Several grid resolution assessment techniques in LES, namely, two-point correlations, ratio of SGS viscosity to molecular viscosity and ratio of SGS shear stress to resolved shear stress were considered. It was found that two-point correlations could be regarded as a useful method for evaluation of grid resolution. However, it was highly time consuming and required extra post-processing calculation. Also, it was shown that ratios of SGS viscosity to molecular viscosity and SGS shear stress to resolved shear stress decreased by improving grid resolution and they did not change significantly by further increasing the grid resolution. Thus, both these ratios were concluded to be an applicable technique for the evaluation of grid resolution in LES.