Abstract
Direct numerical simulation was performed for fully developed turbulent channel flow with lateral (spanwise) non-uniformity of mean temperature (STG) and the same flow but having uniformly heated wall (UHF). For both, two kinds of wall boundary condition were simulated ; steadily constant temperature (iso-thermal) and temporarily constant flux (iso-flux). Through simulations, the Reynolds number based on channel half width and friction velocity was kept at 150, and the Prandtl number at 0.71. Forth order finite differencing was adopted, and 64×127×26 grid points were allocated for computational domain. According to numerical results, regardless of wall boundary condition, the eddy diffusivity ratio, ε_<hz>/ε_<hy>, is found to be nearly equal to the Reynolds normal stress ratio, <w^2>^^^/<v^2>^^^, over the channel width excluding thin layer close to the wall (y^+<1).
