确定空间分布的展向Lorentz力作用下槽道湍流的壁面减阻

摘要

The effect and mechanism of turbulent drag reduction with spanwise Lorentz force of steady spa-tial distribution is investigated numerically by direct numerical simulation (DNS). The influence of Lorentz force intensity A and wave number kx on the drag reduction effect, spanwise velocity, streaks, vortex struc-tures near the wall and Reynolds stress distribution is discussed. The results show that the intrinsic and in-duced flows are modified each other, and there is an optimal wave number kx and intensity A in flow control to achieve the largest amount of drag reduction, in which the intrinsic turbulent flow is modified strongly by the induced flow, and on the contrary, the influence of the intrinsic flow on the induced flow is the weakest.%　　文章采用直接数值模拟方法,对具有确定空间分布的展向Lorentz力作用下槽道湍流的壁面减阻效果和减阻机理进行了研究,讨论了电磁力强度A和流向波数kx对湍流流场的展向速度、条带、流向涡、Reynolds应力分布和壁面减阻率的影响。结果表明,湍流固有流场和电磁力诱导流场之间相互调制,存在最优参数A、kx,使得诱导流场主宰壁面边界层,减阻效果最好。