基于重叠网格的阀芯振荡诱导空化的数值模拟

Numerical Simulation of Spool Oscillation Induced Cavitation with Overset Mesh

锥阀作为调压阀在工作过程中受到外部激励作用不可避免的会发生轴向振荡,诱导流场中出现空化现象,空化初生、发展及溃灭与阀芯振荡耦合在一起,导致整个液压系统的压力发生大幅波动。针对这一问题,基于OpenFOAM开源平台二次开发出具有动态重叠网格功能的两相空化流求解器,对阀芯振荡诱导空化现象进行数值模拟,结合实验与数值计算结果得出:阀芯振荡关阀阶段阀腔中油液受到惯性作用向出口流动,产生大范围低压区,在低压影响下促使气核剧烈膨胀,在阀腔下游产生二次空化;阀芯振荡开阀阶段阀口处压力梯度大,压差驱动油液高速通过阀口产生射流,导致阀口处形成射流空化,这将为高性能液压阀的设计提供理论依据。

As a pressure regulating valve,the poppet valve will inevitably oscillate axially under the external excitation during the working process,inducing cavitation in the flow field,and the initial birth,development and collapse of cavitation are coupled with the oscillation of the valve core,resulting in large fluctuations in the pressure of the entire hydraulic system.In order to solve this problem,based on the OpenFOAM open source platform,a two-phase cavitation flow solver with dynamic overset mesh function was developed for the second time,and the numerical simulation of the cavitation induced by the valve core oscillation was carried out,and the results of the experiment and numerical calculation were combined:the oil in the valve cavity in the valve cavity in the valve spool oscillation closing stage was inertia to flow to the outlet,resulting in a wide range of low pressure area,which promoted the violent collision of gas cores under the influence of low pressure,and produced secondary cavitation downstream of the valve cavity;The pressure gradient at the valve port in the spool opening stage is large,and the pressure difference drives the oil to pass through the valve port at high speed to generate a jet,resulting in jet cavitation at the valve port.This will provide a theoretical basis for the design of high-performance hydraulic valves.