A rocket-based combined cycle engine with expandable air intake

Abstract

The invention discloses a rocket-based combined cycle engine with an expandable air inlet, which includes an isolation section and a mixing section connected in sequence, the isolation section is provided with a first-stage air inlet, and the mixing section is provided with a second-stage inlet near the isolation section. The air port; the primary air intake and the secondary air intake are connected in parallel on the air intake of the engine, so that the primary air intake and the secondary air intake can be opened and closed independently without interfering with each other; on the mixing section An adjustment structure is provided for adjusting the opening width of the secondary air inlet. Through the secondary air inlet, the expanded secondary air inlet can be opened in the injection mode, so that the flow rate of the injected secondary flow can be improved, and the opening size of the secondary air inlet can be adjusted by adjusting the structure, It can better control the air volume of the secondary flow; it will not occupy the space range that the center rocket should have, and the combination with the concave cavity can reduce the total pressure loss caused by the concave cavity at low speed.

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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