CFD Evaluation for a Poppet Valve

摘要

A Computational fluid dynamics (CFD) evaluation study, using ANSYS/CFX CFD commercial software, was performed on a poppet style relieve valve. The study was performed to estimate the pressure drop vs. flow characteristics in side-to-nose flow at various axial poppet positions. Different seat geometry configurations were used in this study. An experimental test rig was built to measure flow and pressure drop across the valve at precisely measured axial poppet positions. The CFD analysis was used to correlate pressure drop vs. flow rate results with the experimental data. A mesh-independent study was performed to find the adequate number of elements across the poppet opening for mesh-independent solutions. Two-equation shear stress transport (SST) and k- turbulent models showed to be more adequate than the k- model for this type of flow. However, pressure recovery from flow reattachment using a longer seat edge could not be captured with any of the two-equation models. This study also demonstrated that a simplified axi-symetric model accurately predicted pressure vs. flow characteristics compared with the 3D analysis results.