Method for acquiring static operation pressure matching point of ultrasonic rapid jet flow of jet wind tunnel

Abstract

The invention discloses a method for acquiring static operation pressure matching points of ultrasonic rapid jet flow of a jet wind tunnel. The method comprises the following steps: firstly calculating the initial opening of a pressure regulating valve at a lower threshold value of initial reference operation total pressure, then changing the opening of the annular gap pressure regulating valve in a stepped manner, obtaining nozzle outlet static pressure, test chamber reference point static pressure and stable section total pressure in real time through a pressure acquisition system, and then calculating the nozzle outlet Mach number and the test chamber reference point Mach number; after the nozzle outlet Mach number is stable, the moment when the nozzle outlet static pressure is the same as the test chamber reference point static pressure is found, and the stable section total pressure corresponding to the moment is the matching point operation total pressure; and if the matching point does not appear, the initial reference operation total pressure is adjusted and then searching is continued. According to the method for obtaining the static operation pressure matching point of the ultrasonic speed jet flow of the jet flow wind tunnel, the optimal operation pressure of the ultrasonic speed jet flow in a specific test state can be rapidly determined, and a traditional ultrasonic speed jet flow field uniform area is expanded to a jet flow boundary area from a rhombus area.

Description

technical field [0001] The invention belongs to the technical field of high-speed free-jet wind tunnel tests, and in particular relates to a method for obtaining a static operating pressure matching point of a supersonic jet in a jet wind tunnel. Background technique [0002] In traditional high-speed free-jet wind tunnels, supersonic tests are usually carried out by increasing the total operating pressure. This method can ensure uniform air flow in the diamond-shaped area of ​​the nozzle outlet. However, the airflow will undergo repeated expansion acceleration and compression deceleration processes outside the rhombic area and within the jet boundary, which makes the quality of the flow field outside the rhombic area deteriorate sharply. The uniform airflow within the diamond-shaped area can be used for small-angle-of-attack inlets, engine characteristics, and other tests that require less uniform area range, and the model scale cannot exceed the range of the diamond-shaped...

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Problems solved by technology

[0004] The significant advantage of the high-speed free-jet wind tunnel is that the blockage of the model is allowed to be large, but the uniform

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