Direct numerical simulation on relevance of fluctuating velocities and drag reduction in turbulent channel flow with spanwise space-dependent electromagnetic force
Jiang Dai-Wen, Zhang Hui, Fan Bao-Chun, Wang An-Hua
       

The distribution of streaks at y +=5 in the flow field before and after control with the optimal electromagnetic force: (a) Re=4000, (b) Re=5000, (c) Re=6000, and (d) Re=7000.