Onset of aerodynamic side forces at zero sideslip on symmetric forebodies at high angles of attack

Abstract

Selected results are presented from extensive wind-tunnel tests that include variations in axial and cross-sectional shape, fineness ratio, bluntness, strakes, and boundary-layer trips over a wide range of conditions (angles of attack to 90 deg, angles of sideslip to 30 deg, Reynolds numbers from subcritical to supercritical, and Mach numbers from 0.1 to 0.7). Pointed forebodies at zero sideslip can experience side forces as large as maximum normal forces. The angle of attack at the onset of side force can be correlated with nose angle and afterbody length. Furthermore, these side forces can be reduced or eliminated by bluntness or nose strakes.