Experimental and numerical analysis of flow force compensation methods for hydraulic seat valve

This paper describes experimental and Computational Fluid Dynamics (CFD) analyses of the interior flow characteristics and flow forces in conical seat valves. Two fundamental flow force compensation methods were investigated in order to establish a correlation between the overall flow field and the internal valve geometry. The first method involved controlling the fluid momentum at the valve orifice, and the results showed that the flow forces increased with decreasing core angle. The second method consisted of balancing the axial fluid momentum, by designing a lip on the rear edge of the poppet. In this case, the flow force was found to decrease, depending on the mass flow and distance between the orifice and the lip. Experimental results are reported together with a detailed discussion of simulated flow pattern and pressure distribution on the internal valve geometry. The flow force compensation methods were analysed to assess the reliability for varying viscosity. Finally, some considerations regarding the CFD simulation method applied for a design exercise are presented.