Rocket-based combined cycle engine thrust calculation method

Abstract

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 initial design of the engine and trajectory planning of an aircraft.

Description

technical field [0001] The invention relates to the technical field of rocket-based combined cycle propulsion forecasting, in particular to a thrust calculation method for a rocket-based combined cycle engine. Background technique [0002] As one of the combined cycle propulsion methods, the Rocket Based Combined Cycle (RBCC) engine combines ejector rockets and ramjet engines to share a flow path, through the secondary flow (that is, the inhaled air and the subsequent flow of air) , the same below) and the mainstream (that is, the rocket wake, the same below) to improve the propulsion performance, to achieve zero-speed (or subsonic) start, accelerated climb, hypersonic cruise and enter the earth orbit. [0003] The rocket-based combined cycle (RBCC) engine is generally composed of (variable geometry) inlet, isolation section, ejection rocket, combustion chamber (or secondary combustion chamber) and (variable geometry) tail nozzle, which can realize ejection mode, sub-fuel r...

AI Technical Summary

Problems solved by technology

In the one-dimensional thrust estimation of RBCC engine, since both diffused bulk combustion (DAB) and instant mixed combustion (SMC) need to assume that the primary flow and secondary flow are completely mixed to obtain the final estimation results, the estimation results are not ideal when the aircraft is flying at low speed , only suitable for use in scram mode

Although independent ram flow (IRS) is suitable for low-speed flight, it lacks a corresponding fast estimation method for thrust. Solving the flow equation directly will consume a lot of computing resources and time, and is not suitable for thrust estimation of RBCC engines under a large number of operating conditions.

Therefore, for the estimation of rocket-based combined cycle (RBCC) engine thrust, especially the estimation of rocket-based combined cycle (RBCC) engine thrust during climb, the existing methods cannot meet the requirements

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