Low-speed wind-tunnel measurements of the oscillatory lateral aerodynamic derivatives of a BAC 221 model and comparison of results with similar Concorde and HP 115 data

Abstract

An oscillatory rig has been used to measure a complete set of low-speed lateral derivatives for the BAC 221 slender ogee-wing research aircraft. Tests covered the angle of attack range 0° to 26° and, at some angles of attack, measurements were also made at sideslip angles of ±5°. Comparison of the BAC 221 results with Concorde and HP 115 data shows that derivatives due to rate of roll are similar; nv and particularly (np + nv. sin α) increase markedly with angle of attack for the HP 115 although not for the Concorde and BAC 221.