Regimes of flow over a 6:1 prolate spheroid

The flow around an inclined 6:1 prolate spheroid is a commonly studied canonical problem that exhibits a variety of complex phenomena found in immersed bodies. At angle of attack, the boundary layer separates and rolls up to form a counter-rotating pair of vortices which contribute to a large part of the loads on the spheroid. The present study aims at understanding the effects of Reynolds number and angle of attack regime of separation and the topology of these vortices using large-eddy simulation. A wall-resolved approach is adopted to examine the flow topology for six angles of attack varying from 10 to 90 degrees at Reynolds numbers ranging from 1 million to 4 million based on length and freestream velocity. Different shedding behaviors and vortical structures are observed depending on the two considered parameters, which in turn influence the dynamic loads on the prolate spheroid.