An In-depth Study on Drag Reduction of Turbulent Channel Flow Induced by Spatially Oscillating Lorentz Force

Abstract

To investigate the in-depth mechanism of turbulence control and drag reduction in a channel flow by using a spatially oscillating Lorentz force, the pseudo-spectral method based on standard Fourier–Chebyshev spectral method is used to solve N-S equations. The characteristics of controlled flow fields and vortex structures are described as well as the mechanism of the flow field control. The result shows that the near-wall flow structure is altered substantially and the turbulence drag decreases sharply under the action of the distributed Lorentz force with proper control parameters, the boundary-layer fluid are reciprocating periodic moving, and the vortex generation is impacted, and that only periodically well-organized streamwise vortexes are observed in the near-wall region of the turbulent channel flow.