Nomenclature

A new model is developed to more accurately capture the dynamics and control of an air-breathing hypersonic vehicle using a computationally inexpensive formulation. The vehicle model integrates a scramjet engine analysis tool developed specifically for use in a control-oriented model and a six-degree-of-freedom rigid-body flight dynamics model. The combined hypersonic vehicle model requires less than ten seconds with a single 2.6 GHz processor to calculate the total thrust, lift, and aerodynamic moment on the vehicle. The inlet and nozzle analysis handles shock-shock and shock-expansion interactions, and expansions are considered to be a series of discrete waves. The combustor model utilizes scaling laws that retain some of the fidelity of higher-order simulations. On the parts of the vehicle that are not part of the propulsive flowpath, modified shock-expansion theory is used to calculate the pressure. In this approach the role of the propulsive model will be only to calculate the net forces and moments on the inlet, combustor, and nozzle. The result is a control-oriented hypersonic vehicle model that qualitatively captures the nonlinear interactions between vehicle dynamics and the scramjet engine