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针对中心喷射式射流真空泵传能效率较低,吸气残压过大的问题,结合环形射流和自激振荡射流的优点,提出环形水气自激振荡脉冲射流的概念,提高射流对被引射气体的卷吸能力。以环形射流理论为基础,建立了质量和动量守恒方程。采用Realizable k-ε紊流模型,欧拉多相流模型对环形水气自激振荡脉冲射流流场进行了数值模拟。以提高卷吸效果为优化目标,对影响卷吸效果结构参数进行了数值计算和分析,完成相关参数正交仿真验证,并获得一组较优的结构参数组合。使用较优参数组合建立环形水气自激振荡射流的模型,并对下喷嘴处的流体平均速度进行了非定常模拟计算。结果表明,与普通环形水气射流相比,环形自激振荡射流对气体的卷吸作用能力,且环形水气自激振荡射流的结构参数对吸气量有显著的影响。这为环形水气自激振荡射流真空泵结构设计提供了理论基础。
In view of the problem of low energy transfer rate and excessive suction residual pressure of the central jet jet vacuum pump, the concept of circular jet self-oscillating pulsed jet is proposed based on the advantages of circular jet and self-oscillating jet, Gas suction capacity. Based on the annular jet theory, the mass and momentum conservation equations are established. Realizable k-ε turbulence model and Eulerian phase flow model are used to simulate the self-oscillating pulsed jet flow field of annular gas. In order to improve the entrainment efficiency as the optimization objective, the structural parameters affecting the entrainment effect were numerically calculated and analyzed, the orthogonal simulation of the relevant parameters was completed, and a set of optimal structural parameter combinations were obtained. The model of ring-shaped water vapor self-oscillating jet was established by using the optimal combination of parameters, and the unsteady simulation of the average velocity of the fluid at the lower nozzle was carried out. The results show that the annular self-oscillating jets have the ability of entraining the gas, and the structural parameters of the ring-shaped water vapor self-oscillating jets have a significant effect on the inspiratory volume. This provides a theoretical basis for the structural design of annular water vapor self-oscillating jet vacuum pump.