Oscillating viscous flow over prolate spheroids

The axisymmetric viscous oscillating flow over a prolate spheroid is considered. The oscillations are harmonic and the free stream is always parallel to the spheroid major axis. The flow is governed by the Strouhal and the Reynolds numbers as well as the spheroid axis ratio. In the present paper, we only investigate the effect of Reynolds number while keeping the Strouhal number and the axis ratio unchanged. The results are presented in terms of the periodic variation of the drag coefficient, pressure, surface vorticity, separation angle, the wake length, and the streamline and vorticity patterns for Reynolds numbers ranging from 5 to 100. Upon averaging the stream function and vorticity over one complete oscillation, the double boundary-layer structure observed in the case of a sphere is confirmed for the range of parameters considered.