Modeling and simulation of a generic hypersonic vehicle

Abstract

Horizontal take-off and horizontal landing hypersonic vehicles are a subject of great interest for future space launch missions. The ramjet/scramjet engine has the potential to enable a new class of spacecraft, missiles, and launch vehicles. This research covers the six degrees-of-freedom (6-DoF) modeling and simulation of a generic hypersonic vehicle (GHV) including a ramjet/scramjet propulsion system and an aerodynamic database. Newton's and Euler's equations are used to develop the longitudinal and the lateral-directional equations of motion. Analytical methods are employed to find the aerodynamic and propulsion models. The optimized trajectory for a generic hypersonic vehicle is developed exclusively for modeling and simulation purposes. The key contributions of this research are: (1) This model is the first complete and comprehensive 6-DoF simulation of an airbreathing hypersonic vehicle in the open literature. This model uses both traditional lookup tables as well as a unique approach using nonlinear analytical expressions. The developed simulation framework includes: (A) The aerodynamic model is developed using wind tunnel experimental investigations and the best available CFD results from high fidelity and engineering level codes (STARS and APAS) uniquely integrated and verified. This technique in developing the aerodynamic model is used efficiently in a multidisciplinary manner to improve the CFD results for the generic hypersonic vehicle. (B) The integrated aero-propulsion system model is the first analytical model for a generic hypersonic vehicle published including iv regenerative cooling effects. The mathematical model of the aerodynamics and the propulsion system can be implemented easily within a conceptual design frame. The propulsion system model is applicable to hypersonic missiles, manned aircraft, unmanned aerial vehicle systems, and access-to-space systems. (C) The developed aerodynamic and propulsion systems for the generic hypersonic vehicle allow a trajectory to be optimized for the vehicle. The optimized trajectory for the generic hypersonic vehicle is uniquely designed including both thrust and aerodynamic forces rather than the simple point mass model usually seen in the open literature. (2) The linearized model of the generic hypersonic vehicle includes all pertinent lateral-directional states. This is the exception for published hypersonic vehicle models in the open literature. The combined longitudinal and lateral-directional models of the generic hypersonic vehicle can be used for control and navigation research. (3) The developed generic hypersonic vehicle model contains aerodynamic, propulsion, atmospheric, and mathematical modules. The modular structure of the simulation makes it easy to change any module efficiently according to the design criteria.