Abstract:Computational Fluid Dynamics (CFD) method was adopted in this paper to analyze the inner flow of valve cavity with different cone neck diameters. The mass flow rate, flow coefficient, cone resistance and steady flow force of hydraulic poppet valve were obtained at different uncork. Based on the simulation results, it has shown that the change of valve cone neck diameter D will not cause the change of mass flow rate when the valve opening is a constant, and the flow coefficient is almost a constant around 0.86; valve cone neck diameter D has small influence on the cone resistance and steady flow force. With the increase of valve opening, the cone resistance gets decreased, however, the steady flow force gets increased during this process.