外啮合齿轮泵内部两相流动的数值模拟

摘要

应用动网格和气穴模型,对某外啮合齿轮泵进行三维数值模拟研究,分析齿轮泵的总体性能和内部流场特性,得出齿轮泵流量随进口压力减小的变化规律,模拟其内部气穴的产生、运输以及破灭过程.计算结果表明,在齿轮泵的工作过程中啮合处会产生气穴.若泵进口腔的压力较高,气穴就会随着工作液的填充而迅速消失,齿谷输送的工作液中不会包含气穴,齿轮泵的流量只会随进口压力的降低略微下降；若泵进口腔的压力过低,气穴不但难以消失,而且还会被齿谷输送走,导致齿轮泵质量流量迅速下降.齿轮泵进口压力越低,则输送的工作液中气体所占的比体积越高,质量流量下降越明显.%The overall performance and internal flow field of an external gear pump was numerically simulated using 3D two-phase unsteady method. Results show that cavitations are created in the work progress of gear pump. If the inlet pres sure is high enough that cavitations will be filled with liquid rapidly and the mass flow will decrease slightly as the decrea sing of inlet pressure. If the inlet pressure is low enough that cavitations can't be filled rapidly. Cavitations will be sent to the outlet and the mass flow will decrease obviously. Mass flow will decrease accelerative as the inlet pressure decreasing lower.