Unsteady High-Speed Flow in the Tank for Fuel Cell Vehicle on Filling the Gas

In the high-pressure tank for Fuel Cell Vehicle (FCV), the shock wave might be occurs during filling of the hydrogen gas because of the high-pressure ratio. Therefore, the temperature sensor in the high-pressure tank might be affected by the shock wave. In this work, we investigated the effect of unsteady flow including shock wave by visualizing around the exit of filling pipe in the Schlieren method. As the result of visualizing the filling pipe exit, it confirmed that pressure wave following the barrel shock wave occurred at high pressure ratio.