EVALUATION OF ENERGY-TRANSFER BETWEEN GRID SCALE AND SUBGRID SCALE BYUSE OF DIRECT NUMERICAL-SIMULATION DATA-BASE

Energy transfer between grid scale(GS) and subgrid scale(SGS) induced by SGS stress in large eddy simulation is investigated by direct numer ical simulation of homogeneous isotropic turbulence and a turbulent mi xing layer. From the results of this study, the following conclusions were reached. (1)No correlation between the Leonard term and Cross ter m exists from the viewpoint of energy transfer. (2)The Smagorinsky mod el for the Reynolds term predicts very large energy transfer compared with that obtained from the DNS data. (3)The Bardina models for the Re ynolds term and Cross term predict large energy transfer from SGS to G S in the high wave number region, which indicates that the Bardina mod el causes excessive backward scattering in the high wave number region .