结冰风洞试验段云雾粒径测量与控制实验研究

Experimental study on droplet size measurement and control of icing cloud in icing wind tunnel

准确测量与控制云雾粒径对结冰风洞开展试验具有重要意义。为了研究3m×2m结冰风洞的云雾粒径特性及其影响因素,应用相位多普勒飞行探头系统(PDI-FPDR)开展试验段云雾平均体积直径(MVD)的测量与控制实验,获取了不同状态下的MVD变化规律,通过综合对比分析,探索了压力、风速、温度等因素对云雾粒径的影响。结果表明:云雾粒径对喷雾系统水压、气压的变化十分敏感,且MVD与喷雾气压成反比;气流风速和温度对风洞中云雾液滴的蒸发和碰撞特性影响不明显,MVD受其影响不大,不同状态的最大相对偏差在±10%的误差范围内;MVD受风洞环境负压作用而显著减小。

Accurately measuring and controlling the droplet size is important for icing wind tunnel tests.To study droplet characteristics and its effects in the 3m×2m icing wind tunnel,a PDI-FP(Phase Doppler Interferometer Flight Probe)system is used for the MVD(Median Volume Diameter)measurement and control test,and the effect factors such as pressure,airspeed,and temperature are analyzed.The experimental results show that there are sensitive relationships between the droplet size and spray air/water pressures.The MVD is inversely proportional to the spray air pressure.The air speed and temperature don’t have impact on MVD obviously with the maximum deviation less than±10%.The MVD is significantly reduced by applying negative pressure.