A rocket-based combined cycle engine variable geometry side pressure inlet

Abstract

The invention discloses a variable geometry side pressure type air inlet passage of a rocket-based-combined-cycle (RBCC) engine. Grading adjustment is conducted with the adoption of a variable geometry mode to ensure that the air inlet passage has good properties within the working range of 1.5-7 Ma. The variable geometry side pressure type air inlet passage captures the air volume by lowering the low Mach number to achieve low Mach number start of the air inlet passage; an auxiliary passage is opened by rotating a second pressure pushing plate; part of airflow is introduced into the tail end of a combustion chamber, so that the resistance of the air inlet passage in an ejecting mode is lowered, and meanwhile the airflow introduced into the tail end of the combustion chamber restrains a tail ejecting pipe from overexpansion to increasing thrust, and accordingly the performance of the whole engine is improved by a large margin, and the rate of fuel consumption in the ejecting mode is lowered. The auxiliary passage is closed during the operation in a subsonic-supersonic-combustion mode, and a lip opening plate is moved forward or backward to cover and shelter a certain part of a pressure difference overflow window, so that the flow coefficient of the air inlet passage and the total pressure recovery coefficient are effectively increased. The side pressure type air inlet passage has the advantages of being simple and easy to achieve, and it is ensured that the air inlet passage has good performance during the operation interval of the whole engine.

Description

technical field [0001] The invention relates to the technical field of rocket ramjet engines, in particular to a rocket-based combined cycle engine variable geometry lateral pressure inlet. Background technique [0002] The rocket-based combined-cycle (Rocket-Based-Combined-Cycle, RBCC) engine organically combines the rocket engine and the air-breathing engine in one flow channel, and through mode switching, it can operate optimally at different flight Mach numbers and altitudes. way to work. With the different flight Mach numbers, the rocket-based combined cycle engine mainly experiences four basic working modes: rocket ejection mode, sub-combustion ramming mode, scramming mode and pure rocket mode. The rocket-based combined-cycle engine basically consists of four parts: the inlet, the main rocket embedded in the flow channel, the combustion chamber and the tail nozzle. Affected by the wide envelope of the rocket-based combined cycle engine, the rocket-based combined cycl...

AI Technical Summary

Problems solved by technology

[0004] In the domestic published technical literature, "Study on Variable Geometry Scheme of Hypersonic Side-pressure Inlet" (Nanjing University of Aeronautics and Astronautics, 2012 master's degree thesis), the moving lip and throat roof placement proposed for the side-pressure inlet Air and lip rotation are three variable geometry schemes. The working range of the studied inlet is 4-7Ma, and the performance of the inlet under the ejection mode of the rocket-based combined cycle engine is not involved.

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