Shear layer development in a three-dimensional compressible base flow

The structure and characteristics of the shear layer embedded in a three-dimensional, compressible, separated flow were investigated experimentally. The investigation focused on three primary areas: shear layer initiation at the base-corner separation point, development of the three-dimensional shear layer enclosing the recirculation region, and the turbulence structure near reattachment. The primary data presented are mean velocity and turbulence fluctuations measured using two-Component laser-Doppler velocimetry. Initiation of the shear layer at the base-corner separation point results in an increase of all measured turbulent stresses, and a change in orientation of the turbulent structures. The shear layer growth rate is observed to vary with circumferential angle, with growth occurring at a much faster rate in the leeward plane than in the windward. Throughout the reattachment region, the turbulent stresses do not appear to diminish in the streamwise direction, contrary to previously published results for axisymmetric base flows. In addition, the reattachment phenomenon tends to slightly decrease overall turbulent structure organization.