基于数值模拟的CP型喷射泵喉管长度计算

采用SIMPLE算法和RNGk-ε湍流模型,针对某一种CP型喷射泵的内部流场进行了数值模拟,模拟中考虑几种不同的喉管长度,对比分析了泵的性能和内部流场.结果表明：喉管长度对泵的性能、沿程压力和内部流场有重要影响.不考虑汽蚀因素影响,在2.5-6.0倍喉管直径范围内,喉管越长,喷射泵的最高效率也就越高,最高效率点随之右移.通过对效率、喉管出口断面的动能修正系数、动量修正系数及沿程压力变化曲线的分析,表明在3.7-4.5倍喉管直径范围内,该泵在设计工作点的性能最优.综合以上各因素,该CP型喷射泵最优喉管长度应为喉管直径的3.7-4.5倍.

Calculation of throat pipe length in CP type jet pump based on numerical simulation

Based on SIMPLE algorithm and RNG k-ε turbulence model, numerical simulation was carried out to calculate the inner flow field of the CP type jet pump with throat pipe of different lengths. By comparison and analysis on their performance and inner flow field, it was found that the throat pipe lengths has important effect on the performance, the pressure distribution as well as the inner flow field of the jet pump. Regardless of cavitation, with the length of throat pipe in the range of （2.5 - 6. 0） times of throat diameter, the peak efficiency will also increase and the point of peak efficiency will move to the right to the larger flow rate ratio region. By analysis of the efficiency, the kinetic energy correction coefficient α and the momentum correction coefficient α＇ at the throat outlet section together with the pressure distribution, it revealed that in the range of （3.7 - 4.5 ） times of throat diameter, the jet pump performs best in the design duty point, which must be the optimal length of throat pipe for the CP jet pump.