Separated Flow Surface Pressure Fluctuations and Pressure-Velocity Correlations on Prolate Spheroid

Power spectra of turbulent surface pressure fluctuations and spatial correlation coefficients of surface pressure-velocity are presented for the leeside, three-dimensional, separated crossflow over a 6:1 prolate spheroid at Re L = 4.2 × 106 for angles of attack of 10 and 20 deg. This is a complex, three-dimensional, nonequilibrium flow of practical interest. These results are related to the attached, separated, and reattached features of the vortical flow for a range of Reynolds numbers based on momentum thickness up to 1.5 × 10 4 . The high-frequency surface pressure fluctuation spectra scale on wall variables at low angle of attack. Near regions of separation where wall shear stress is low, there is little high-frequency content, whcreas low-frequency contributions from the outer layer are relatively large. In regions with large surface shearing stresses, the wall region produces strong, high-frequency spectral content. At locations with relatively small outer region mean velocity gradients, there are smaller low-frequency contributions. Both of these features occur around the side of the body and under the large vortices at higher angle of attack