结冰风洞环境对喷嘴雾化特性的影响初步研究

喷雾系统是结冰风洞中进行云雾参数模拟的核心设备,其雾化喷嘴的性能直接影响结冰风洞试验段平均水滴直径(MVD)、液态水含量以及云雾均匀性等关键技术指标。结冰风洞运行过程中的压力、温度、风速以及雾化水滴的温度、初始粒径等均会对进入试验段的云雾参数的最终状态产生影响。在0.3m×0.2m 结冰风洞和喷嘴低压试验台上,针对不同风洞运行环境对喷嘴雾化性能的影响进行研究,测量了风洞运行的压力、气流速度、雾化水滴的温度、初始粒径等对粒子蒸发速率及喷嘴性能包线的影响。研究结果表明:风洞的气流环境对云雾粒子的 MVD值影响较大;风洞的气流速度及粒子的初始温度越高,云雾粒子的雷诺数越大,其蒸发速率越大;环境压力对喷嘴的粒径和包络线影响较大,随着环境压力的降低,喷嘴的流量-粒径包络线整体收窄,但对喷嘴的流量影响不大。

Preliminary research on spray nozzle atomization characteristics in icing wind tunnel environment

The icing cloud inside the icing wind tunnel test section is generated by the Spray Bar System (SBS)which is located at the wind tunnel settling chamber.The icing conditions such as the icing cloud liquid water content (LWC)and water droplet size (MVD)are determined by the performance of the spray nozzle of performance on SBS.The enviromental parameters of the icing wind tunnel operation such as the pressure,temperature,wind speed and diameter of liquid droplet can change the final atomization characteristics in the test section.In the 0.3m× 0.2m icing wind tunnel with low pressure spray nozzle testing platform,we used Phase Doppler Interferometer(PDI)to measure the droplet evaporation rate and spray nozzle performance enve-lope in different icing wind tunnel operation environments.The experimental results show that:the icing wind tunnel flow condition can change the MVD when the liquid droplets fly into the test section through the contraction section;when the wind speed,the temperature and Reynold number of liquid droplet increase,the evaporation rate of droplet will also increase;the ambient pressure has an indispensable influence on the MVD and spray nozzle performance envelope;as the ambient pressure reduces,the spray nozzle flow mass-MVD envelope is narrowed down,but the spray nozzle water flow mass is hardly influenced.These experimental results can be used in the icing wind tunnel for icing cloud simulation and uniformity debugging.