The hydrogen filling tank is a high-pressure vessel designed to store and supply H₂ safely for refueling or experimental applications. For CFD simulations, the inlet is typically defined as a mass flow inlet or pressure inlet (e.g., 0.5 kg/s at 293 K, pure H₂), while the outlet/vent is a pressure outlet (e.g., 0 bar gauge) with ambient air backflow. Tank walls are modeled as stationary, adiabatic walls or using conjugate heat transfer if thermal effects are considered. Initial conditions set the tank at 1 bar and 293 K. Turbulence (SST k-ω) and energy equations are enabled, and species transport is included for H₂. For transient filling, time steps are chosen to maintain CFL ≤ 1 near the inlet, and monitors track tank pressure, temperature, and hydrogen mass.
