Research On The Opening And Closing Process And Cavitation Of Hydraulic Cone Valve Based On Immersed Boundary Method

As one of the commonly used valves in hydraulic components,cone valves have the advantages of small sudden changes in the direction of hydraulic oil flow at the valve port,uniform flow field distribution,and easy production and manufacturing in practical use.Therefore,they have been widely used in hydraulic technology.During the opening and closing process of the cone valve core,the shape of the flow channel at the valve port is relatively complex,which can cause cavitation at the valve port and have adverse effects on the stability and reliability of the hydraulic system.When the cone valve is opened and closed,the generation and collapse of cavitation at the valve port are very rapid,and experimental research requires the use of high-speed cameras for recording.Although experimental research can explain some of the mechanisms of cavitation flow,the complexity of cavitation flow still needs further research,and numerical simulation research can to some extent compensate for the limitations of experimental research.The immersed boundary method has been widely used in numerical simulation research due to its unique advantages in handling complex boundaries.The immersed boundary method can compensate for the technical defect of traditional body-fitted dynamic grids that cause significant mesh deformation when the motion amplitude is too large,which affects the accuracy of calculations and even makes it impossible to perform calculations.In view of the current major mainstream commercial software,such as Simcenter STAR-CCM+and ANSYS Fluent,lack of support for the immersed boundary method,this paper proposes to apply the immersed boundary method to the opening and closing process of the hydraulic poppet valve and cavitation problems,and develops a two-phase cavitation flow solver using the immersed boundary method based on the Open FOAM open source simulation platform.The immersed boundary method is tried in the opening and closing process of the hydraulic poppet valve and cavitation problems,and has good calculation results,At the same time,it also contributes to domestic CFD.The reliability of the solver was ultimately verified by calculating and comparing the two cavitation problems of opening and closing the cone valve with experiments using a solver.The two-phase cavitation flow solver developed in this article using the immersed boundary method was used to analyze the cavitation situation during the opening and closing of the cone valve from three aspects: velocity,pressure,and cavitation cloud map.The reasons for the spatiotemporal cavitation of the valve core opening and closing were identified.In addition,this article also expands the research on the effects of different inlet pressures,different return oil backpressures,and different valve core motion speeds on hydraulic valve port cavitation.Research has found that cavitation during valve opening is caused by high-speed jet flow at the valve port,while cavitation during valve closing is secondary cavitation caused by hydraulic oil inertia.The increase in inlet pressure and the change in movement speed of the valve core during opening and closing will promote the generation of cavitation at the valve port;The change in return oil back pressure will suppress the generation of cavitation at the valve port.The numerical simulation study of the opening and closing process and cavitation of hydraulic cone valves using the immersed boundary method has proven that the immersed boundary method can compensate for the technical shortcomings of traditional dynamic grids,as well as its applicability and feasibility for such problems.By studying the causes of cavitation during the opening and closing process of hydraulic cone valves and the impact of different conditions on valve port cavitation,relevant theoretical basis is provided for improving the comprehensive performance of cone valves in engineering.