Separation control based on turbulence transition around a two-dimensional hump at different Reynolds numbers

摘要

Separation and reattachment around a two-dimensional hump controlled by a two-dimensional periodic excitations induced by a dielectric barrier discharge plasma actuator are investigated at Reynolds numbers of 4000 and 16,000 based on the freestream velocity and the hump height. A two-dimensional excitation is adopted in the present study for promoting two-dimensional instability in the shear layer and a resulting laminar-turbulent transition. Note that the most effective frequency for reattachment is fh(= f*u(infinity)*/h*) = 0.20 among the presently considered cases at both Reynolds numbers, which is close to the reference value previously reported for the flow around a backward-facing step (Masan, 1992).