A fundamental study of the aeroelastic behaviors of vehicles in hypersonic range

Abstract

A fundamental study of aeroelastic behaviors in the hypersonic regime using Time domain analysis and continuation method are presented in this paper based a typical cross-section with the usual pitch and plunge degrees of freedom. Aerodynamic forces for various parameters are calculated using piston theory, with the aeroelastic stabilities of the system for various altitudes are computed by the continuation software package AUTO[1]. These results are verified through comparison with solutions performed by the time domain analysis. Structural non-linearities are then introduced through cubic stiffness in the structural model. This results the development of Limit Cycle Oscillations (LCO’s) in the aeroelastic system near a Hopf-Bifurcation on the flutter boundary. It is demonstrated that the results produced by the continuation software are essentially identical to those calculated in the time domain. However, the continuation method is much more rapid (approximately 10 times more rapid) and may also be used to track unstable paths through the stability boundary, as well as examine the effects on the behaviour of the system of parameter variation independently. This fact is used to examine the evolution of frequencies and altitudes of the LCO across the Mach number range, with variations of physical and structural parameters.