A secondary throat diffuser injecting low total pressure cold medium

Abstract

The invention discloses an ejection low total pressure cold medium adjustable secondary throat diffuser. The ejection low total pressure cold medium adjustable secondary throat diffuser is used at thedownstream of a large hypersonic velocity wind tunnel experimental section, can adapt to operating condition of a wider range by adjusting the amount of ejection air, meanwhile, diffusion capacity isimproved, the working load of a back section ejector is reduced. In addition, a cold medium ejected flows at a near wall region, and the wall surface of the diffuser can be effectively protected frombeing in contact with high temperature fuel gas directly, and the construction cost brought by a cooling water sleeve can be reduced. The novel structure of the diffuser is characterized in that a side wall groove is added in the front of a diffuser convergence section, low total pressure normal temperature air is introduced at the position of the front edge of the groove and used as the cold medium, an air film is formed in the wall surface of the diffuser through the ejection and diffusion effect, the practical flow diameter of a secondary throat is adjusted, the static pressure recovery capability of secondary throat is adjusted at a greater degree, meanwhile, heat load of the wall surface of the secondary throat is reduced again, and the wall surface is cooled; and simulation verification is carried out, even though the ejection cooling medium is an atmospheric condition, the good diffusion and cooling effect can be achieved.

Description

technical field [0001] The invention belongs to the field of supersonic wind tunnel diffusers for aerodynamic equipment, and in particular relates to a secondary throat diffuser for injecting low total pressure cold medium. Background technique [0002] Hypersonic wind tunnels have important applications in military, aviation, aerospace and other fields. It can simulate the aerodynamic environment of aircraft flight. However, in the simulation process, the expansion and expansion capacity and heat load cooling are often two aspects that cannot be ignored; the traditional solution is to install a supersonic secondary throat diffuser with a fixed geometry after the wind tunnel test section, and carry out a certain The degree of diffusion, and then spray water to cool and then be further pressurized and discharged by the ejector. In order to improve the diffusion capacity of the supersonic secondary throat, the front section of the supersonic secondary throat diffuser is gener...

AI Technical Summary

Problems solved by technology

This leads to its low diffusion performance at high Mach number conditions

However, under high Mach number conditions, the static pressure is low and the pressure boost ratio is high, resulting in a non-linear increase in the ejector load and a substantial increase in operating costs.

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