Numerical Simulation On Erosion Wear Of Spool Valve Using OpenFOAM

As the control element of the hydraulic system,the importance of the hydraulic spool valve is increasingly prominent with the advancement of the intelligent manufacturing process.A large number of studies have shown that the small solid particles mixed in the oil will cause erosion wear on the spool valve,and even lead to the failure of the spool valve.Due to the complicated flow field in the spool valve,the research on the erosion phenomenon of the spool valve has been mainly focused on the experiment.Limited by experimental equipment,processing difficulty,manpower and material resources,the experiment can only analyze limited parameters within a limited range.Therefore,with the help of computer simulation technology,it is necessary to systematically study the erosion theory of spool valve comprehensively and efficiently.In this paper,with the help of the Eulerian-Lagrangian solver in the open source software Open FOAM,a numerical solution model of the solid-liquid two-phase flow of the slide valve is established.By implanting the erosion model,the existing solver can calculate the erosion quantity and its related parameters.Based on the simulation and experimental data,some erosion models are optimized for the flow field characteristics of the spool valve.The effects of flow parameters such as particle diameter and injection concentration,oil viscosity and flow direction,and differential pressure on erosion rate and related parameters were systematically studied.The following conclusions were mainly obtained:1.The effect of oil viscosity and particle diameter on the erosion wear is basically the same in mechanism.The larger the viscosity is,the smaller the impact angle and impact velocity are,resulting in a decrease in erosion rate.The increase in particle diameter will cause the impact angle to increase,the impact velocity to decrease,and the impact frequency to increase,which will eventually lead to the increase of erosion rate first and then slowly decrease.2.The differential pressure and the spool opening have similar effects on the erosion wear.A larger differential pressure will bring a larger impact velocity and erosion rate;increasing the spool opening will lead to an increase of particle impact velocity and erosion rate.3.As the particle injection concentration increases,the number of injected particles increases,at the same time the particle impact frequency increases and the erosion rate increases linearly.4.Changing the flow direction and gravity direction will lead to the change of particle trajectory,which will make the erosion rate change slightly.