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.