Experimental study on cryogenic nitrogen/liquid nitogen jet condensation oscillation
In order to explore the characteristics and mechanism of low-frequency vibration of rockets,a cryogenic experimental system of gas-liquid jet condensation was established with a vi-sualization test section using liquid nitrogen.The oscillating flow pattern was captured by a high-speed camera and the pressure pulsation was measured by the cryogenic high-frequency dynamic pressure sensor,which provided a factual basis for the low-frequency vibration of the rocket.Using the image processing method,it can be seen that the two-phase interface fluctuated periodi-cally at a frequency of 16 Hz.From the flow pattern observations,three distinct flow regimes,i.e.,suck-back,transition and gas plume oscillation flow were observed.The suck-back fre-quency increased with the increase of nitrogen volume flux and liquid nitrogen mass flux,and the condensation oscillation frequency increased with the increase of nitrogen volume flux and de-creased with the increase of liquid nitrogen mass flux.The suck-back frequency was 0.8-2.8 Hz,and the condensation oscillation frequency was 16.6-17.8 Hz,showing typical low-frequency os-cillation characteristics.It provides the theoretical basis and technical support for the low-frequen-cy vibration of the cryogenic liquid fuel launch vehicles.
cryogenic liquid nitrogenjet condensation oscillationflow pattern transitionlow frequency fluctuationsflow instability
万方数据
维普
