Coupled Flight Dynamics and Thermoelasticity Model of Maneuvering Aircraft

Abstract

The stress and strain tensors in maneuvering aircraft are affected not only by the aerodynamic and propulsive forces but also by the body translational and angular velocities and high rate temperature distributions. The structural design of flexible aircraft requires the elastic fields to be evaluated at high accuracy. For this, new models that couple the aeroelasticity equations with the heat and translational and rotational equations of flight dynamics are essential. In this paper, the governing equations are derived by describing the motion of a thermoelastic body in an undeformed body frame by means of the variational principle applied to four invariants: the kinetic energy, the gravitational potential energy, the thermoelastic potential, and the dissipation function. Particular cases of longitudinal and lateral flight dynamics of a thermoelastic body including longitudinal flight of a thermoelastic beam are considered. Also, a discrete system for the translational and rotational velocities, the structural modes, and nodal temperature is derived. These equations may advance control design of hypersonic platforms, flexible aircraft, and missiles.