某型氢氧火箭发动机射前预冷改进方案试验研究

Experimental study on improved ground precooling scheme of a hydrogen-oxygen rocket engine

为了简化射前操作流程,提高火箭发射可靠性,开展了针对某燃气发生器循环氢氧火箭发动机的射前预冷方案改进研究。研究使用了两台真实发动机,在向下倾斜45°的试验台上进行了8次真实介质下的预冷试验,其中6次进行了模拟任务剖面的预冷和点火试验。试验表明,某型氢氧火箭发动机射前预冷由增压预冷改进为大流量自流预冷的方案是可行的,改进后预冷时间能够满足发射流程的要求,可以最大程度上避免液氧供应管路发生"间歇泉"不稳定现象。通过模拟任务剖面进行预冷试验,表明发动机点火前氢、氧系统均能达到预冷好条件,但氧涡轮端轴承后温度比改进前偏高。6次点火试验表明,改进后的射前预冷方案未对发动机点火、起动过程造成明显影响。

In order to simplify the launch operation and improve the launch reliability, an improved ground precooling scheme for a hydrogen-oxygen rocket engine of gas generator cycle was studied. Two real engines were tested and 8 precooling tests were carried out under real media,on a test bench of 45 degrees downward,6 in which were hot test. It shows that the scheme of high flow gravity discharge pre-eooling is feasible. There is plenty of time to cool down the engine in the launch process and the Geyser Instability in the oxygen supply pipe can be minimized. By simulating flight mission profile, it was confirmed that both the hydrogen and oxygen system can be cooled down before the engine ignition,but the temperature of the oxy- gen turbine bearing was higher than before. By the 6 hot tests,it was showed that the improved ground pre- cooling scheme had no obvious influence on the ignition and starting process of the engine.