为了搭建更加精确的离心泵汽蚀工况的性能预测模型，将汽蚀工况下的泵内流动分为入口段和出口段分别计算流量，以两段流量之差确定泵内空泡体积，进而确定汽蚀的扬程相对降低系数。通过5种型号泵的仿真结果与水试结果对比验证了该建模方法的通用性和准确性，最大计算偏差出现在第二临界点附近，约为1%；针对热试中汽蚀故障进行仿真复现，和热试结果对比验证了该故障建模方法的有效性。在此基础上开展了补燃循环液氧煤油发动机氧化剂泵汽蚀故障的注入与仿真，结果表明：预压泵入口压力降低能够导致氧化剂泵汽蚀；汽蚀工况下，氧化剂主泵扬程降低、流量减少并且转速升高；进而导致燃气发生器混合比趋向当量比、温度升高，与理论分析和试车以及发射中故障结果相吻合。最低允许预压泵入口压力为53%额定入口压力，继续降低压力会导致燃气发生器温度超过临界温度，存在产生毁灭性后果的危险。
In order to build a more accurate performance prediction model of centrifugal pump under cavitation condition,the flow in the pump under cavitation condition is divided into inlet region and outlet region, and the volume of cavitation in the pump is determined by the difference of two-stage flow so that the relative reduction coefficient of cavitation head is determined. The simulation results of five types of pumps are compared with the hydraulic test results to verify the universality and accuracy of the modeling method. The maximum calculation deviation occurs near the second critical point, which is about 1%. The simulation results of cavitation fault in hot test are compared with the results of hot test to verify the effectiveness of the modeling method. On this basis, the injection and simulation of the cavitation fault of the oxidant pump in the staged combustion cycle liquid oxygen kerosene engine are carried out. The results show that the reduction of the inlet pressure of the pre-pressure pump can lead to the cavitation of the oxidizer pump; under the cavitation condition, the head of the oxidant main pump decreases, the mass flow rate decreases and the revolution increases; and therefore, the mixture ratio of the gas generator tends to the equivalent ratio and the temperature increases. The results are consistent with the theoretical analysis and hot test, as well as the fault in launch. Minimum allowable boost pump inlet pressure is 53% rated inlet pressure, so reducing the pressure continually will cause the gas generator temperature exceed the critical temperature, which may lead to devastating consequences.
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