Subsonic and transonic aerodynamics of a wraparound fin configuration

Abstract

Abstract : Subsonic and transonic aerodynamic data for a wraparound fin configuration are presented. Free-flight aeroballistic tests to obtain these data were conducted at atmospheric pressure and over a Mach number range of 0.6 to 1.35. The aerodynamic coefficients and derivatives presented in this paper were extracted from the position-attitude-time histories of the experimentally measured trajectories using nonlinear numerical integration data reduction routines. Results of this analysis indicate that a dynamic instability exists above Mach 1.0 and is related to an out-of-plane side moment which is dependent of the pitch angle. The stability boundaries associated with this side moment are mapped. Designers should consider this moment whenever wraparound fins are used. Keywords include: WAF(Wraparound Fins), Aerodynamic stability, Side moment, Pitch-roll resonance, Folding fins, and Submunitions.