Rocket-based combined cycle engine with expandable air inlet

Abstract

The invention discloses a rocket-based combined cycle engine with an expandable air inlet. The rocket-based combined cycle engine comprises an isolation section and a mixing section which are sequentially connected; a first-stage air inlet is formed in the isolation section; a second-stage air inlet is formed in the position, close to the isolation section, of the mixing section; the first-stage air inlet and the second-stage air inlet are connected to an air inlet channel of the engine in parallel so that the first-stage air inlet and the second-stage air inlet can be opened and closed independently and do not interfere with each other; and an adjusting structure is arranged on the mixing section and is used for adjusting the opening range of the second-stage air inlet. The expanded second-stage air inlet can be opened in an injection mode through the second-stage air inlet, so that the flow amount of injected secondary flow is increased, the opening size of the second-stage air inlet can be adjusted through the adjusting structure, the air inflow of the secondary flow can be better controlled, the space range of a central rocket cannot be occupied, and the total pressure loss caused by the concave cavity can be reduced at the low-speed section through combination with the concave cavity.

Description

technical field [0001] The invention relates to the technical field of rocket-based combined cycle engines, in particular to a rocket-based combined cycle engine with an expandable air inlet. Background technique [0002] The ejection rocket is an important part of the RBCC (Rocket-Based Combined Cycle) engine, and it is the main source of engine thrust in the ejection mode (when the flight Mach number is less than 3). In order to ensure sufficient power for the aircraft, the size of the ejector rocket is relatively large, accounting for more than 40% of the total cross-sectional area of ​​the flow channel, which makes the secondary flow channel in the isolation section relatively narrow. Due to the ejection and suction effect of the center rocket, the secondary flow can easily reach the speed of sound in the narrow flow channel, forming a blockage. At this time, the flow of the rocket is further increased, and the flow of the secondary flow cannot be increased. [0003] In...

AI Technical Summary

Problems solved by technology

In order to ensure sufficient power for the aircraft, the size of the ejector rocket is relatively large, accounting for more than 40% of the total cross-sectional area of ​​the flow channel, which makes the secondary flow channel in the isolation section relatively narrow. Due to the ejection and suction effect of the center rocket, the secondary flow can easily reach the speed of sound in the narrow flow channel, forming a blockage. At this time, the flow of the rocket is further increased, and the flow of the secondary flow cannot be increased.

[0003] In addition, when the center rocket performs afterburner operation, the rocket plume flow rate and total pressure increase, and the secondary flow rate cannot be increased, the rocket plume in the mixing section will further squeeze the secondary flow channel, or even completely Blocking the flow of the secondary flow, because the flow of the secondary flow is suppressed, at this time, the RBCC engine will not be able to organize the secondary injection combustion of the fuel at the rear, and the whole actually degenerates into a rocket engine

[0004] In the prior art, in order to solve the problem of secondary flow congestion in the isolation section, the isolation section is chosen to be a gradually expanding structure, but this will occupy the volume of the center rocket, which may cause problems such as insufficient thrust

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