Visual Analysis And Research On Flow Field Of Slide Valve Based On Different Structures Of CFD

In the fluid transmission control system,various types of control valves are used to control the flow direction,pressure,flow of the fluid and to realize the control of the movement and speed of the actuator.And it is ensured that the actuator drives the load to work as designed.Spool valve type hydraulic valve is one of the most important control valves,which uses the relative movement of the valve core to the valve body to control the opening and closing of the oil circuit or change the direction of the flow to control the start,stop and commutation of the actuator.There are many types of slide valve structures and sizes used in actual production.It is difficult to observe the actual flow state of the liquid flow in the slide valve through experiments.Therefore,the flow field state of the hydraulic oil is visualized through the flow field microscopic view.The valve core shape and other parameters are changed to improve the flow characteristics of the spool flow field and the working performance of the spool valve.When the liquid flows through the spool valve port,the trajectory of the fluid in the valve will be redistributed.In the process,the valve orifice will cause energy loss.And there will also be vortices generated at the valve chamber and corners of the valve groove,which causes noise,leads to energy loss and affects spool valve performance.Therefore,this article mainly discusses the vortex characteristics in the valve and the factors that affect the distribution and strength of the vortex,so as to achieve the control of the vortex development inside the valve,improve the energy efficiency in the valve and the performance of the slide valve.In this paper,the three-dimensional fluid simulation models of the spool valve are established by UG,the geometric models of different structures are completed in GAMBIT,Tetrahedral and hexahedral hybrid meshes are used to complete the meshing of the model,and local refinement of the grid is used for key research areas such as corners.Fluid simulation(CFD)method is used to simulate and visualize the flow field in slide valve by Fluent.Firstly,under the two conditions of inlet and outlet throttling,the steady state simulation is performed for the models with different openings,and the influence of the opening size on the flow field distribution in the inlet and outlet throttle valves is coMPared and analyzed.Secondly,under the condition of inlet throttling and the same opening,the effects of different inlet speeds and different outlet pressures on the flow field distribution in the valve are co MPared and analyzed.Finally,according to the influence of the opening and the different boundary factors on the flow field in the valve,the vortex distribution and strength in the valve are qualitatively and quantitatively analyzed.Based on the analysis results,the bottom corner structure of the valve core groove is improved.The bottom of the traditional slide valve groove is in the form of a right angle,mainly for the convenience of processing,but with the advancement of processing technology,numerical control processing has become very common.The processing of the groove into any shape does not increase the processing cost.Therefore,in this paper,the right-angle structure of the bottom of the valve core groove is changed to circular arc type and angled arc type,and the improved models are simulated and calculated by Fluent.The distribution graphs of the velocity,pressure and turbulence energy of the slide valve with different valve core structures are coMPared and analyzed,and the rationality of structural improvement is verified theoretically.