全尺寸进气道射流预冷数值研究与性能评估

Numerical Study and Performance Evaluation of Jet Precooling in Full-Scale Inlet

关键词:  射流预冷  进气道  降温量  蒸发效率  温场均匀性

Key words:  Jet precooling  Air inlet  Temperature decrease  Evaporation efficiency  Uniformity of temperature field

摘要:

针对高马赫数高温条件下飞机进气道射流预冷问题，本文建立了真实飞机全尺寸进气道-射流预冷装置一体化数值计算模型，通过控制变量法分析了进气流量、进气温度及射流流量对射流预冷装置性能的影响规律，发现进气流量与降温量呈负相关，与蒸发效率和温场均匀性呈正相关；进气温度与降温量、蒸发效率及温场均匀性均呈正相关；射流流量与降温量呈正相关，与蒸发效率及温场均匀性呈负相关。研究结果表明，在相同进气状态下，此飞机进气道的特殊构型会导致降温量和蒸发效率曲线在蒸发距离为2500mm处存在拐点。在此基础上，进一步提出了一种基于试验设计法（Design of experiment，DOE）评估进气道出口总温的评估方法，与试验结果对比发现该方法可将误差控制在5%以内。因此，采用该方法进行进气道出口总温预估是有效的。

Abstract:

Aiming at the jet precooling problem of aircraft inlet at high Mach number and high temperature，an integrated numerical calculation model of full-scale inlet jet precooling device for real aircraft is established in this paper. The effects of gas flow rate，intake temperature and jet flow rate on the performance of jet precooling device are analyzed by controlling variable method. It is found that the gas flow rate is negatively correlated with temperature decrease and positively correlated with evaporation efficiency and uniformity of temperature field. The intake temperature is positively correlated with temperature decrease，evaporation efficiency and uniformity of temperature field. The jet flow rate is positively correlated with the temperature decrease and negatively correlated with the evaporation efficiency and uniformity of temperature field. The results show that under the same inlet conditions，the special configuration of the aircraft inlet will cause the inflection point of the cooling capacity and evaporation efficiency curve at the evaporation distance of 2500mm. On this basis， an evaluation method for evaluating total temperature at the outlet of the inlet based on design of experiment is further proposed. Compared with the experimental results， it is found that this method can control the error within 5%.Therefore， it is effective to use this method to predict total temperature at the outlet of the inlet.