Tensorial time scale in turbulent gradient transport of Reynolds stresses

Abstract

On the notion that the Reynolds stresses are transported with different time scales depending on the transport direction, the third-order velocity correlations are represented by a new turbulent gradient transport model with a tensorial Lagrangian time scale. In order to verify the proposed model, DNS data are first obtained in a turbulent channel flow at Re-tau = 180 and 300, and tensorial Lagrangian time scales are computed. The present model predictions are compared with direct numerical simulation data and those predicted by the third-order turbulent transport model of Hanjalic and Launder that uses a scalar time scale. The result demonstrates that the Reynolds stresses are indeed transported with different time scales depending on the transport direction. c 2005 American Institute of Physics.