Reynolds Number Effects on Cone Forebody Side Force

Abstract

This paper reports results from comprehensive pressure measurements of a circular cone-cylinder model in a low-turbulence 3.0 × 1.6 m low-speed wind tunnel. The semi-apex angle of the cone is 10 ◦ . The results consist of detailed pressure distributions over nine stations on the cone at 35 ◦ angle of attack and free-stream Reynolds number of (0.1 0.9)×10 6 based on the cone base diameter. The tests encompassed a complete coverage of roll angles in 9 ◦ intervals. Local and overall forces and moments are calculated from the measured pressures. The variation of local side-force coefficient normalized by the local diameter of the cone, with roll angle is nearly a square-wave curve. At Re = (0.7,0.9) × 10 6 , the maximum side force is reduced, which is caused by late separation of the boundary layer, and irregular values of side force occur at a few roll angles, which is correlated to disagreement of separation asymmetry with pressure asymmetry. Important asymmetry features which are valid for all of the Reynolds numbers are clarified.