蛇形进气道影响下发动机进口部件水撞击特性的数值研究

Numerical Study on Water Droplets Impingement on Aero-Engine Entry Components with a Serpentine Inlet

关键词:  蛇形进气道  欧拉/欧拉法  发动机进口  支板  整流罩  水撞击

Key words:  Serpentine inlet  Eulerian/Eulerian method  Aero-engine entry  Struts  Spinner  Water droplets impingement

摘要:

为了了解亚声速蛇形进气道影响下航空发动机进口段迎风表面处的水滴撞击特性，采用欧拉/欧拉法对蛇形进气道和发动机进口段在来流马赫数为0.3及环境温度为266.5K的大气结冰条件下进行了空气/过冷水滴两相流场的计算，再由已获得的水滴流场进行支板表面水撞击特性的计算。整流罩表面水滴的撞击计算时采用插值的方法将原两相流场的计算结果插值到新生成的整流罩的近壁网格处，之后采用新生成的整流罩面网格进行水撞击特性的计算。通过计算获得了发动机进口结冰参数、支板以及整流罩表面水收集系数的分布。计算结果表明整流罩和支板表面水滴撞击的主要区域与进气道的弯曲方向有关且位于其下表面一侧，最大水收集系数达到0.98。与之相对比的整流罩和支板其他区域的水收集系数则显得非常微小，在数值上约等于0。此外，对于与进气道对称面平行的竖直支板，其与机匣相交的区域存在水收集系数为0遮蔽区。

Abstract:

In order to get water droplets impinging characteristic on the up-wind surface of aero-engine entry components under the influence of a serpentine inlet，the Eulerian/Eulerian method was taken to calculate the two phase flow field，which was composed of air and super-cooled water，under an atmospheric icing condition of free stream Mach number 0.3 and environmental temperature 266.5K. And then the calculation of water droplets impingement on the surface of the struts was based on the obtained water droplets flow field. Several layers of new grid，to which the previously calculated two phase flow field was interpolated，were generated on the surface of the spinner and then used for its water droplets impingement calculation. The distribution of icing parameters at the aero-engine entry and water collection efficiency on the surface of struts and the spinner were obtained after the calculation was finished. The results show that the location of the main area of water droplets impingement is related to the bending direction of the serpentine inlet and the main area locates on the lower surface of the struts and the spinner and the maximum water collection efficiency on this area reaches 0.98. By contrast，water collection efficiency in other areas of the struts and the spinner is very low and the value approximately equals to zero. In addition，there is a droplets shadowed zone，whose water collection efficiency is zero，around the intersection part between the spinner and the strut which is parallel with the inlet symmetry plane.