Low Mach number system of trisonics wind tunnel

Abstract

The invention discloses a low Mach number system of a trisonics wind tunnel, and mainly aims at expanding the M number range of wind tunnel test and enhancing the test capability of the wind tunnel. The system comprises a gas source, a main pipe, a main pressure regulating valve, a jet pipe, a test segment and an expansion segment, the main pressure regulating valve is mounted on the main pipe which is connected between the gas source and the jet pipe, the main pipe is provided with a bypass which communicates the front with the back of the main pressure regulating valve, the bypass is provided with a baffle plate with holes and a side valve, and the baffle plate with holes is placed in the upstream of the side valve. Thus, the M number of a blowdown wind tunnel extends downwardly and is better connected to the M number of the low speed wind tunnel test, and requirements for test of more models can be met.

Description

technical field [0001] The invention relates to a system capable of adjusting a three-sonic wind tunnel to a lower Mach number, and belongs to the technical field of wind tunnel tests. Background technique [0002] M=0.3 is of great significance to improve the test capability and market demand of the sub-span super-temporary wind tunnel. However, the minimum Mach number of existing subspan supertemporal wind tunnels is usually around M=0.4. In actual work, the model unit often hopes that the M number covers as much as possible in a wind tunnel blowing test, so as to maintain the integrity and consistency of the data. Due to the difference in the flow field quality of different wind tunnels and the existence of test system errors, if the low M number is placed in the low-speed wind tunnel for wind tunnel tests, and the remaining M numbers are carried out in the sub-span super wind tunnel, the error of the data system will be larger. Correction and connection of data under d...

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Problems solved by technology

However, if a single pressure regulating valve is used for control, even if a valve with good regulation characteristics is used, its characteristic curve is still difficult to take into account all Mach number ranges, and it is unfavorable to the wind tunnel pressure regulation accuracy and running time at non-design points.

This is mainly because sufficient flow is required to establish a high Mach number flow field, so the design of the incoming flow cross-section cannot be too small. On the one hand, it is very difficult to manufacture and process large-diameter valves. On the other hand, even if the processing meets the use requirements, Also, because the incoming flow cross-section is too large, it is necessary to make the opening of the main regulator valve small to obtain a small flow when establishing a low Mach number flow field. At this time, it is difficult to obtain a stable front chamber pressure and a uniform flow field, especially for gas In the case of high source pressure, forced to deflate for a long time

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