CFD Study For The Flow Field Inside The Hydraulic Spool Valve Considering Of The Movement Of Valve Element

The hydraulic spool valve is one of the most important components in the hydraulic transmission and control, whose function is to control flowing direction and discharge of fluid in hydraulic control system, whose characteristics of the inner flow field directly influents the valve's performance, especially the moving valve element.In the paper, the circular opening spool valve is investigated, applying CFD method, respectively in the two conditions of metering-in spool valve and the metering-out spool valve, both the static valve element and the moving valve element, for different velocity, the hydraulic oil flow inside the spool valve is simulated. The following are the main contents:1, The 3-D geometric models of spool valve are built by utilizing software Pro/E, according to its actual structure and parameters as well as feasibility of computational mathematical model. Models are transformed and imported into Gambit software to generate mesh.2, The flow field inside the spool valve is visualizing analysis at different conditions. When the spool valve element is moving, the hydraulic oil flow is simulated by setting the dynamic mesh. Through the user define function; the velocity of the valve element is defined. Comparing the path line, velocity distribution, turbulent kinetic energy and pressure distribution in the spool valve, it offers the theory foundation for designing spool valve with high efficiency, low energy loss and low noise.3, On the basis of simulation, for different moving conditions and different velocity, the characteristic in the metering-in spool valve and metering-out spool valve is researched and analyzed. The results show that the transient flow force is big enough and must be considered when the valve is in small throttle with large flow and high moving speed. Through the analysis of the hydraulic force act on the valve-pole, there is an additional radial force that causes valve element lockup existed, and this force is not be noticed during the previous design. This force is difficult balanced with only structure method. The study for the valve has offered the significant reference to designing the valve and optimizing the performance.The project is the study content of the National Natural Science Foundation of China "Improving and application study on flow force's compensating methods and calculating formula of the hydraulic valve". Foundation program number: 50675147...