Flow characteristics and noise diagnosis of hydrogen charging solenoid valve in hydrogen- fueled automobile

There is a growing interest in green vehicles, such as hydrogen powered fuel cell cars, along with the increase in public awareness towards the environmental issues. However, with compressed systems applied for fuel storage purpose, refueling of hydrogen causes an issue, during which high-pressure hydrogen from the station storage tank passes through filling components before entering the empty tank in the vehicle. In this state, as the pressure difference between the station tank and the vehicle tank can be very high, the complexity of solenoid valve geometry creates complex flow characteristics (turbulence and interaction of gas and wall) that could generate intense pressure fluctuation and excessive noise. This paper presents the results of a three-dimensional simulation for characterizing the complex flow inside the solenoid valve and for diagnosing flow-induced noise generated during the charging process at different valve openings and pressures. Simulation is carried out using computational fluid dynamics (CFD) by implementing appropriate turbulence and viscous models. Firstly, the simulation is conducted in a steady state condition to investigate the acoustic power and to localize the regions that are most likely to be affected. In addition, transient simulations are performed to obtain the frequency of the pressure fluctuation inside the solenoid valve. The results provide accurate and useful data about flow pattern inside the solenoid valve and additionally, furnish information to determine the sources, locations, and characteristics of flow-induced noise generated within the solenoid valve. This investigation can be applied to reduce the undesirable noise and to analyze the possibility of system failure due to flow-induced vibrations.