Direct Numerical Simulation of Turbulent Thermal Boundary Layer

Abstract

Direct numerical simulations (DNS) of a turbulent thermal boundary layer along a uniformly heated wall with zero pressure gradient has been conducted. The computational domain is composed of two parts : one is the driver part where the inflow boundary condition is constructed, and the other is the main simulation part. In the driver part, inflow conditions for the velocity field are generated by using the well-established universal velocity profile, and those for the thermal field are made in a similar manner. DNSs are carried out under two conditions, i.e., the Reynolds numbers based on the momentum thickness at the inlet are set at 300 and 600,and the Prandtl number is 0.71. The distributions of the friction coefficient and the Stanton number mimic very well the respective empirical laws. Moreover, the mean velocity and temperature profiles are simulated quite sufficiently, thus indicating that further discussion on the structure of turbulence is legitimate.