THERMAL LATTICE BOLTZMANN SIMULATIONS OF VARIABLE PRANDTL NUMBER TURBULENT FLOWS

Thermal lattice Boltzmann (TLBE) models that utilize the single relaxa tion time scalar Bhatnagar, Gross, and Krook collision operator have a n invariant Prandtl number. For flows with arbitrary Prandtl number, a matrix collision operator is introduced. The relaxation parameters ar e generalized so that-the transport coefficients become density indepe ndent. TLBE simulations ate presented for two-dimensional free decayin g turbulence induced by a strongly perturbed double velocity shear lay er for various Prandtl numbers.