基于凝结实验平台的音速喷嘴凝结现象研究

Study on condensation in sonic nozzle based on experimental condensation apparatus

音速喷嘴中流动的蒸汽或含湿气体由于自身的温降而发生凝结现象,对音速喷嘴的计量会产生一定的影响。针对音速喷嘴凝结现象和自激振荡的复杂变化情况,利用一套凝结实验平台研究了音速喷嘴内湿空气凝结现象,得到了不同条件的喷嘴沿程压力,并建立了凝结流动Eulerian两相模型,对凝结现象的影响因素进行了数值分析,使实验结果得到了验证和补充。结果表明,载气的压力、温度、湿度会对凝结产生比较大的影响。凝结发生位置伴随载气温度、湿度的提高而前移,强度有所增大。随着载气压力的增大,凝结发生位置前移,但是强度相对减弱。自激振荡的频率与载气湿度、温度呈正相关,与载气压力呈负相关,振幅与载气的压力、温度、湿度均呈正相关。

The temperature of water vapor and moist gas will drop greatly in the sonic nozzle,which leads to the condensation and will have a great effect on the measurements. Aimed at the phenomenon of condensation and self-oscillation of sonic nozzle,an experimental condensation apparatus was set up to observe the condensation of moist air in sonic nozzle,and the pressure distribution under different conditions was obtained. To validate and supplement the experimental data,a gas-liquid two-phase flow Eulerian model was established through numerical analysis of influence factors on condensation. The results show that the inlet pressure,humidity and temperature have a great influence on condensation phenomenon. With the increase of humidity and temperature,the location of condensation moves forward and the intensity also increases. With the increase of the inlet pressure,the location of condensation moves forward,while the intensity weakens. The frequency of self-oscillation is positively related to the humidity and temperature,and negatively related to the inlet pressure. The amplitude is positively related to the inlet pressure,humidity and temperature.