Hypersonic wind tunnel diffuser and design method thereof

Abstract

The invention discloses a hypersonic wind tunnel diffuser and a design method thereof. The diffuser comprises an original diffuser body and further comprises a detachable built-in diffuser body installed in the original diffuser body. The design method of the diffuser comprises the steps: selecting the axial installation distance, the contraction angle, the diameter of an equal straight section, the length-diameter ratio and the divergence angle of the built-in diffuser as design parameters based on the size of an original diffuser and the size of a spray pipe outlet; obtaining a three-dimensional configuration based on the composition relation of the original diffuser and the built-in diffuser; generating a grid based on the three-dimensional configuration, and selecting a typical wind tunnel state corresponding to the spray pipe with the minimum outlet diameter to perform anti-back-pressure efficiency simulation; adjusting design parameters of the built-in diffuser through an optimization algorithm, and carrying out the global iteration optimization by taking improvement of anti-back-pressure efficiency as a target. The diffuser is simple in structure and can flexibly adapt to test requirements of the hypersonic wind tunnel. According to the design method of the diffuser, the design sample space can be greatly enriched, and the defect that design is carried out purely depending on experience is overcome.

Description

technical field [0001] The invention belongs to the field of hypersonic wind tunnel equipment, and in particular relates to a hypersonic wind tunnel diffuser and a design method thereof. Background technique [0002] The hypersonic wind tunnel is an important ground equipment supporting the development of hypersonic aircraft. The diffuser is an important part of the hypersonic wind tunnel. The effect of elevation on the wind tunnel flow field, thus prolonging the test time. However, there are complex boundary layers and shock train structures inside the diffuser, which affect the outlet pressure of the diffuser and the high pressure of the downstream vacuum system. Therefore, optimizing the diffuser is of great significance to improve the performance and efficiency of hypersonic wind tunnels. [0003] However, in the hypersonic wind tunnel design process, designers usually determine the diffuser parameters based on previous wind tunnel debugging experience. Continue to ad...

AI Technical Summary

Problems solved by technology

However, in existing hypersonic wind tunnels, in order to reduce the cost of wind tunnel construction, reduce equipment replacement time, and improve operating efficiency, multiple sets of nozzles are usually used to share a set of diffusers, which requires the size parameters of the diffuser trade-offs, to ensure that a set of diffusers can be used for multiple sets of nozzles as much as possible, and is most suitable for a certain set of commonly used nozzles, which leads to the inability of a set of diffusers to achieve good resistance in a wide simulation range. Back pressure efficiency

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