一种新型动态畸变模拟器数值模拟及试验测量研究

Numerical Simulation and Test Measurement Study on a New Dynamic Distortion Generator

关键词:  进气道/发动机匹配  畸变模拟器  数值模拟  复合畸变  动态畸变  试验测量

Key words:  Inlet/engine matching  Distortion generator  Numerical simulation  Complex distortion  Dynamic distortion  Test measurement

摘要:

为了更准确地模拟真实进气道出口畸变，更好地评估进发匹配性能，设计了一种新型动态畸变模拟器，其主要利用扰流柱产生流向涡团，形成总压与旋流复合畸变，并利用外部射流形成畸变流场的动态变化。数值模拟结果表明：无射流工况下，模拟器下游可以产生总压与旋流复合畸变流场，畸变有一定的脉动程度；定常射流工况下，时均流场畸变程度增强，但畸变脉动程度降低，流场接近稳态；给定非定常射流后，畸变脉动程度显著增强，总压和旋流畸变指数均有剧烈波动，其中总压畸变指数标准差达到0.089，旋流畸变指数标准差达到0.077。试验测量结果表明：随着进口马赫数增加，非定常射流工况下紊流度占比达到41%~56%，综合畸变指数达到10%以上，满足实际工程中进发匹配试验对进气畸变的要求。

Abstract:

In order to more accurately simulate the aircraft intake outlet distortion and better evaluate the inlet/engine matching performance， a new dynamic distortion generator was designed， which mainly used the column to generate the flow direction vortex， forming the combined distortion of total pressure and swirl， and used the external jet to form the dynamic distortion.Numerical simulation results show that under the condition of no jet flow， the downstream of the generator can produce a combined distorted flow field of total pressure and swirl， and the distortion has a certain degree of pulsation. Under the steady jet， the distortion amplitude of the time averaged flow field increases， but the degree of distortion pulsation decreases， and the flow field is close to steady state. After the unsteady jet is given， the degree of distortion pulsation is significantly enhanced， and the total pressure and swirl distortion index fluctuate violently. The standard deviation of distortion index for total pressure and swirl reaches 0.089 and 0.077. Test measurement results show that with inlet Mach number increases， turbulence intensity accounts for 41%~56% under unsteady jet condition and the multiple distortion index is above 10%， which meets the requirements of the inlet distortion for inlet/engine matching test in practical engineering.