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 variations of drag reduction rate with amplitude and wave number for different Reynolds numbers: (a) Re=4000, (b) Re=5000, (c) Re=6000, and (d) Re=7000.