A Periodically Rotating Distributed Forcing of Flow over a Sphere for Drag Reduction

In the present study, we propose a periodically rotating distributed forcing for turbulent flow over sphere its drag reduction. The blowing/suction is applied on finite slot of surface near separation, and unsteady sinusoidal velocities are azimuthally surface. This profile rotates in azimuthal direction time with frequency, satisfying instantaneous zero net mass flux. Reynolds number considered Re=104 large eddy simulations conducted to assess control performance. It shown that reduction performance varies results classified into low-frequency ineffective, effective reduction, high-frequency saturation regimes. With frequencies regime, helical vortex generated from evolves shear layer, this responsible separation delay reattachment resulting base pressure recovery maximum about 44% frequency while controls other regimes do not produce