Compact Eddy Structure of Turbulence Aft of an Inclined Slender Body

The compact eddy structure and the correlation structure of three distinct turbulent boundary layers were investigated, with a view to understanding the turbulent inflow seen by a stern-mounted propulsion tail rotor. The first is of a zero-pressure-gradient, equilibrium, flat plate boundary layer, and the second and third are on the lee and port sides of a body of revolution (BOR) inclined at a 5° angle of attack. The BOR is an axially symmetric body with an ellipsoidal nose, straight midbody, and 1.17-diam-long stern ramp with a stern-mounted tail rotor. Measurements on the BOR were taken at a body-diameter-based Reynolds number of 600,000 and a rotor advance ratio of [Formula: see text]. Particle image velocimetry was taken at two principal locations at the stern of the BOR. Distortion of the correlation function was evident in the compact eddy structure of the BOR boundary layer on both the lee and port sides. On the port side, the turbulent modes were dominated by the embedded shear layer, whereas the lee side showed more significant pressure gradient effects in the eddy structure.