Multi-physics simulation for a pressure relief valve

This thesis aims to investigate the interaction between the multibody dynamics and fluid dynamics of a pressure relief valve for hydraulic applications. The performance of a hydraulic valve is significantly influenced by flow forces generated due to changes in fluid momentum within the valve. These flow forces consist of three components: a steady-state factor, directly proportional to the flow rate and fluid velocity, and two unsteady factors, dependent on the flow rate derivative and spool acceleration, respectively. The first contribution, which is the most influential, consistently tends to decrease the flow area. It has been proven that, under a constant pressure drop across the valve, the steady-state force is directly proportional to the spool displacement, resembling the behavior of a virtual spring. In the present work, the behavior of the valve was investigated by means of the co-simulation tool developed by MSC Software, which allows to couple multibody simulations with fluid dynamic simulations. The main goal of this study is to validate the model through co-simulation and propose variations for further exploration. The outcomes will provide useful data to deliver practical insights in the understanding of system-fluid dynamics interactions.