抄録
Turbulent heat transfer in horizontal Couette-Poiseuille flows heated from below is investigated numerically at fixed Reynolds number Re = 2000 and for bulk Richardson numbers Ri = 0, 0.01, 0.1. In this flow system the u_<upper> wall moves at a temporally constant speed u_<upper>, while the lower wall is at rest. For an invariant volume flux and so a constant bulk mean velocity u_b, the upper wall speed is changed in the range of 0 ≤ u_<upper>/u_b ≤ 2 to establish the Couette-Poiseuille flows. It is found that the dimensionless wall heat flux (Stanton number St) takes a local maximum for a certain value of u_<upper> at which the mean velocity gradient on the upper wall is null. For larger Ri (= 0.1) this local maximum of St is observed to be global.
