Internal flow phenomena of anti-water hammer air valves

Air valves play a critical role in mitigating water hammer issues, as their internal flow dynamics are directly linked to their protective performance. This study provides a comprehensive examination of fluid flow within air valves, focusing on intake and exhaust under anti-water hammer conditions to elucidate their operational mechanisms. A three-dimensional model of the air valve has been developed, integrating computational fluid dynamics simulations with experimental data to investigate the flow characteristics thoroughly. The results reveal that during large-scale exhaust, throttled exhaust, and negative pressure intake phases, the internal flow velocity and pressure of the air valve display symmetrical distributions. However, variations in boundary conditions and internal structures significantly affect the flow field distribution, velocity gradients, and pressure profiles. Furthermore, the study investigates the impact of differing air content and flow rates internal flow field of air valves under standard operating conditions. By examining these flow phenomena, the research enhances understanding of air valves' role in water hammer protection and contributes to addressing related protective challenges.