Rocket-based combined cycle engine thrust calculation method

The invention provides a rocket-based combined cycle engine thrust calculation method. Firstly, one-dimensional geometrical parameters of an inner flow channel of the rocket-based combined cycle engine are determined and include an air inlet channel inlet sectional area, an air inlet channel compression angle, an e isolation section sectional area, a sub-expansion section expansion ratio, a combustion chamber expansion ratio, a rocket combustion chamber sectional area, a rocket nozzle size and an engine exhaust nozzle expansion ratio; the flight height, the flight Mach number and the mainstream flow are input; and then thrust estimation is conducted on the rocket-based combined cycle engine, and the final thrust of an outlet of an exhaust nozzle of the rocket-based combined cycle engine and the specific impulse of the engine are obtained. According to the method, rapid estimation of thrust and specific impulse performance of the rocket-based combined cycle engine is achieved, and a newtool is provided for ini