Isentropic analysis and numerical investigation on high-pressure hydrogen jets with real gas effects

Abstract The present work performs the isentropic analysis and numerical simulation of high-pressure hydrogen jets to study the hydrogen leakage. The exit parameters and the flow characteristics are studied with the ideal gas assumption and real gas effects. The jet exit parameters calculated by the real gas thermodynamic model are different from the results obtained by the ideal gas assumption at high initial pressure based on the isentropic analysis. The ideal gas and the real gas equation of state results in the differences of Mach disk parameters at high initial pressures. The ideal gas assumption underestimates the Mach disk distance by 8% and overestimates the Mach disk diameter by 15% at the initial pressure of 50 MPa. The exit mass flow rates computed from the isentropic expansion assumption agree well with the numerical simulations. The results show that it is reasonable to evaluate mass flow rates of high-pressure hydrogen jets by the isentropic expansion assumption.