レイノルズ応力成分の散逸のモデリング

抄録

This paper develops a new model for the nonisotropic dissipation rate tensor ε_ij to close the Reynolds-stress transport equations. The previous models of ε_ij are all algebraic, based on a hypothesis of either the isotropic relationship of the dissipation tensor or the one-to-one relationship of the dissipation anisotropy tensor with that for the Reynolds stresses. However, the recent direct simulation data of the turbulent boundary layer and channel flow have revealed the strongly nonisotropic nature of the dissipation process, which differs considerably from that of the Reynolds-stress components. The present model provides nonisotropic dissipation-rate components through the solutions of approximated transport equations for ε_ij, and hence, the conventional prescription of an ad hoc value of ε_ij is not needed. The proposed model is tested by direct comparisons with the reported full simulation data to validate the performance of the model predictions.