Flow studies of axisymmetric bodies at extreme angles of attack

Abstract

Results of a background investigation and initial theoretical models are described for the flow about axisymmetric bodies at extreme angles of attack. Present state-of-the-art is described with the general conclusions that the current understanding of extreme angle of attack flow phenomena is relatively well developed for angles of attack up to about 40 degrees (symmetric vortex pair in the wake) and that for higher angles of attack there are several important questions yet to be answered. The initial analytical model qualitatively predicts the occurrence of induced yaw forces and is suggested as a basis for further refinements and experimental comparisons. Expressions for the calculation of local forces and pressure distributions are developed for the case of an axymmetric steady vortex wake. (Author)