2022 年 17 巻 1 号 p. JFST0001
In this study, we investigated the effect of anticyclonic spanwise rotation on the plane Couette flow at the small Reynolds number Rew = 1300, defined by the moving wall velocity, channel half-width, and kinematic viscosity by direct numerical simulations using the spectral method. We confirmed that at the typical rotation number, the mean velocity distribution became the S-shape, and a negative velocity gradient appeared in the channel centre. At this rotation number, the significant decrease in sweep event, i.e., inrush motion of high-speed fluids toward the wall, and an increase in ejection, i.e., the outward motion away from the wall, were observed in the wall vicinity. In addition, the budget of turbulent kinetic energy showed that the transport of turbulent energy into the wall vicinity was suppressed, and the dissipation rate there was attenuated, which indicated the relaminarization there. Finally, visualization of an instantaneous flow showed that the generated secondary flow swept small-scale vortices near the wall away from the wall.
