CFD-BASED DESIGN AND OPTIMIZATION OF A CRYOGENIC PISTON VALVE FOR LIQUID HYDROGEN FLOW CONTROL

Thanks to their reliability and accuracy, piston valves are widely used in pressure regulation systems. This is especially true in the aerospace sector, where cryogenic fluids such as liquid hydrogen are commonly handled, making the design and operation of these valves particularly critical. However, the development of piston valve technology for cryogenic applications is still relatively limited, mainly because of the challenges involved in creating systems that can operate reliably in such harsh conditions. This highlights the need for more detailed studies and simulations using CFD tools and predictive models. To achieve efficient and stable performance of a piston pressure-regulating valve in a cryogenic environment, it is essential to understand both the strengths and the limitations of this technology under extreme thermal and mechanical loads. The work presented here focuses on a preliminary analysis and optimization of a piston valve operating with liquid hydrogen for pressure control purposes. Special attention is given to the dynamic behavior of the piston body, particularly regarding the robustness and controllability of its response. The study explores the motion of the piston in a low-viscosity flow, as well as the thermodynamic and fluid-dynamic characteristics of the valve system. Flow field simulations are carried out using CFD tools, and the results are combined with system response data obtained from a Simulink dynamic model. Finally, the outcomes are critically analysed to identify the regions where the valve is most affected by thermal and mechanical stresses, suggesting possible design improvements.