Compendium of Flight Mechanics Formulae Applied to Hypersonic Gliders

Abstract

Hypersonic gliders are a new family of aerospace vehicles. They operate at quasi-orbital velocities with centripetal acceleration balancing part of gravity. Although their aerodynamic finesse is modest effective gravity, resulting from combined effects of gravitational field and of centripetal acceleration allows achieving considerable ranges and flight durations. With relatively modest aerodynamic lift, such vehicles can achieve prolonged lateral maneuvers with relatively small adverse effects on their cruising performance. This study presents an extension of traditional flight mechanics formulae that include relative gravity factor. The paper presents a derivation of such factor with significant fidelity, by taking into account not only velocity magnitude and flight altitude but also the impact of latitude and ground track angle exert on Earth curvature and thereby on centripetal acceleration. Optimum cruising strategy is presented together with formulations of flight time, cruising altitude and range which were satisfactorily compared with high fidelity simulation results.