Modeling of hypersonic vehicles propulsion system

In order to quickly obtain the thrust and moment of thrust at the early design stage, and satisfy relevant modeling and analysis control, a model for the propulsion system of hypersonic vehicle was proposed. An inlet model was developed based on the wave interaction method. Moreover, the dual-mode combustor was modeled by an increasing area duct with heat addition and friction, whereas the internal nozzle was modeled by a variable area duct with friction. Accordingly, the thrust was estimated according to the momentum theory, and then analytical expression was obtained by a curve-fitting method. Compared with the result of CFD, the error of Mach number and temperature at the dual mode ramjet engine inlet was less than 5%, and the pressure error was less than 10%; the computed thrust increased as Mach number, stoichiometrically normalized fuel-to-air ratio and angle of attack increased, and decreased as height increased; the time cost of one state point was less than 0.5s averagely. Computation result demonstrates that the proposed modeling approach meets the high efficiency and accuracy required in the control-oriented modeling process, contributing to the analysis and design related to dynamics and control of the hypersonic vehicles.