环形引射器两相流动数值模拟
吴薇梵1,2,王占林1,2,孔凡超1,2,刘瑞敏1,2,李 茂1,2

(1.北京航天试验技术研究所,北京 100074; 2.北京市航天试验技术与装备工程技术研究中心,北京 100074)

环形引射器; 蒸汽引射器; 数值模拟; 相变; 真空

Numerical simulation with two-phase flow in annular ejector
WU Weifan1,2, WANG Zhanlin1,2, KONG Fanchao1,2, LIU Ruimin1,2, LI Mao1,2

(1.Beijing Institute of Aerospace Testing Technology, Beijing 100074,China; 2.Beijing Engineering Research Center of Aerospace Testing Technology and Equipment, Beijing 100074,China)

annular ejector; steam ejector; numerical simulation; phase change; vacuum

备注

蒸汽引射器是上面级火箭发动机进行高空模拟试验时获得真空的重要设备。采用数值模拟方法,通过Fluent对氢氧火箭发动机高空模拟试验用环形蒸汽引射器内部流场进行了研究,分析水蒸气两相流动及不同的入口工况和结构尺寸对极限真空压力的影响。考虑水蒸气的两相流动,在数值模拟中加入了水蒸气的凝结相变模型,并通过试验数据开展了模型验证,验证结果为:加入相变模型后极限真空压力降低,仿真结果更接近试验数据。在此基础上,研究了喷嘴入口工况和引射器结构尺寸对极限真空压力的影响,仿真结果表明:在引射器能够启动的条件下,降低蒸汽入口总压或提高入口总温,减小喷嘴出口壁厚或增大混合室直径,均能降低引射器的极限真空压力。因此,若想提高引射器真空度,可以通过改变入口工况或调整引射器结构尺寸来实现。

The steam ejector is an important equipment for the upper stage rocket engine to obtain vacuum during the high altitude simulation test.The numerical simulation method and Fluent was used to study the internal flow field of the annular steam ejector used in the high altitude simulation test of hydrogen oxygen rocket engine.The influences of two-phase flow in water vapor, different inlet conditions and structure sizes on the ultimate vacuum pressure were analyzed.Considering the two-phase flow of water vapor, the condensation phase change model of water vapor was added into the numerical simulation, and the model was verified by the test data.The verification results were as follows, after adding the phase change model, the ultimate vacuum pressure decreases, and the simulation results are closer to the test data.On this basis, the influences of inlet working conditions and structure sizes on the ultimate vacuum pressure were studied.The results showed the ultimate vacuum pressure of ejector can be reduced by reducing the total pressure or increasing the total temperature at steam inlet, reducing the wall width at nozzle outlet or increasing the diameter of mixing chamber under the condition that ejector can start.Therefore, improving the vacuum degree of the ejector can be achieved by changing the inlet conditions or adjusting the structure size.