横向加速度对飞行发动机绝热层烧蚀影响的实验研究

设计了实验发动机与实验装置,进行了一系列飞行固体火箭发动机横向过载模拟试验,获得了不同加速度下发动机内绝热层烧蚀率定量化的试验数据。验证了横向加速度严重影响局部绝热层烧蚀的事实。机理分析表明,此种结果是由于横向加速度作用下燃气中Al2O3液态粒子偏离发动机中心线,沿离心力方向大量沉积所致。此项研究为相关的工程设计提供了基础性的依据。

An Experimental Study of Cooling Film in Negatively Bowed Cascade with Large Turning Angle

Transverse measurements are carried out at the outlet of the straight and negatively bowed turbine cascades with 106° turning angle respectively with and without cooling air injection from holes of the ten rows and from holes of several rows of the ten rows (totally 26 schemes).Experimental results show that negatively bowed cascade produces more energy loss than the straight one without cooling air injection.Cooling air injection from the holes on the pressure surface and from the holes on the suction surface near the trailing edge can reduce energy losses in both the straight and the negatively bowed cascades.The increase in loss is less in negatively bowed cascade than that in the straight one with cooling air injection from holes of several rows at the leading edge,whereas cooling air injection from holes of several rows at the trailing edge reduces the energy loss in the negatively bowed cascade.