发动机冷转情况下液滴入射过程特性分析

Investigation for Droplets Spraying Process in Cold Turning Aero-engine

针对航空发动机在翼清洗过程中射流雾化液滴进入风扇级的运动过程,对其在飞机进气口处的运动特性进行研究。通过航空发动机内气液两相流场以及射流的数值模拟,获得了液流运动和液滴传质传热特性。分析结果显示进入风扇级后液流速度不受喷嘴输入压力的影响;液滴的尺寸越小,经过风扇级后温度和质量损失越大,500μm液滴的温度和质量损失很少,而50μm液滴降温幅度大,质量损失较明显。为飞机发动机清洗系统的研发提供了理论基础。

A numerical method is put forward for the research of the liquid drop motion to simulate the movement law before injected in the fan stage when online washing aero-engine. The study includes the analysis of the mixture phase inside the compressor and the calculations of the motion of the water droplets injected into the air flow. Such parameters as the velocity distribution of the flow velocity and the motion of the droplet heat/mass transfer have been obtained by analyzing the two-phase flow field of the aero-engine and numerically simulating the jet. The analysis results show that the liquid flow in the aero-engine is not affected by the input pressure. Droplets with smaller diameters tend to take the risk of heat and mass loss ： which sizes of 500 microns kept heat and mass well, while which sizes of 50 microns dropped in temperature obviously and lost mass slightly but significantly. The results could be helpful for designers of the on-line aero-engine washing systems.