Apparatus for generating fluctuating counter pressure in air inlet test

Abstract

The invention discloses an apparatus for generating fluctuating counter pressure in an air inlet test. The apparatus includes a throttle rotary vane which is mounted on the outside of a wind tunnel outlet and a drive mechanism which drives the throttle rotary vane to rotate. The throttle rotary vane includes more than 2 rotary vanes and is driven by the drive mechanism to rotate. Each rotary vane, when rotating, can alternatively block a certain area of the wind tunnel outlet so as to generate a throttle. Compared with throttle blockage cones and rotation ellipse methods of prior art, according to the invention, the apparatus can generate a fluctuating counter pressure signal of higher frequency and having adjustable time-average value, vibration and frequency. Also, according to the invention, to generate a fluctuating counter pressure signal of the same frequency requires less rotation speed of the motor.

Description

Technical field [0001] The invention relates to the field of air inlet wind tunnel tests, in particular to a pulsating back pressure generating device. Background technique [0002] The scramjet is mainly composed of intake port-isolation section, combustion chamber and tail nozzle. The intake port-isolation section is an important compression part of the engine, and its downstream is connected with the combustion chamber. In the actual working process of the engine, there is combustion oscillation or combustion instability in the combustion chamber, which causes the pressure in the combustion chamber to pulsate at a certain frequency and amplitude. Therefore, it is necessary to simulate the pulsating back pressure in the study of the influence of back pressure on the inlet-isolation section. . [0003] There are currently two main ways to generate pulsating back pressure: [0004] (1) The throttle device (such as throttle plugging, etc.) is controlled by the motor to periodically ...

AI Technical Summary

Problems solved by technology

[0006] When the scramjet engine is actually working, the pressure pulsation frequency ranges from tens to 200 Hz in the combustion chamber, and the pulsation backpressure frequency that can be generated by the existing technology is less than this range. figure 1 The shown technique can only generate a pulsating backpressure of a few Hertz, figure 2 The technique shown produces a pulsating back pressure of less than 100 Hz and therefore cannot simulate real conditions

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