Surface-pressure pattern of separating flows over inclined slender bodies

Physics of Fluids, Volume 32, Issue 9, September 2020. Surface-pressure measurements and literature review of crossflows over inclined slender bodies at high Reynolds numbers (4.2 × 106 to 17 × 106, based on body length and freestream velocity) show that the constructed pressure maps have a distinct pattern, which relates to large-scale separation. The separation envelope is defined by a pair of primary and secondary surface-bifurcation lines as described by Lee [“Longitudinal development of flow-separation lines on slender bodies in translation,” J. Fluid Mech. 837, 627–639 (2018)]. The present study shows that the separation envelope falls in a “plateau” region in the circumferential distribution of the mean pressure. In the distribution of circumferential pressure gradient, there are two local maxima, where one is located on the windward side of the separation envelope and the other is located on the leeward side. Pattern tracking identifies that the locus of maximum circumferential pressure gradient resembles the locus of separation, but is located further upstream along the slender body.