Delayed Explosion of Hydrogen High Pressure Jets: An Inter Comparison Benchmark Study

Delayed explosions of accidental high pressure hydrogen releases are an important risk scenario for safety studies of production plants, transportation pipelines and fuel cell vehicles charging stations. As a consequence, the assessment of the associated consequences requires accurate and validated prediction based on modelling and experimental approaches. In the frame of the French working group dedicated to the evaluation of computational fluid dynamics (CFD) codes for the modelling of explosion phenomena, this study is dedicated to delayed explosions of high pressure releases. Two participants using two different codes have evaluated the capacity of CFD codes to reproduce explosions of high pressure hydrogen releases. In the first step the jet dispersion is modelled and simulation results are compared with experimental data in terms of axial and radial concentration dilution, velocity decay, and turbulent characteristics of jets. In the second step a delayed explosion is modelled and compared to experimental data in terms of overpressure at different monitor points. Based on this investigation several recommendations for CFD modelling of high pressure jets explosions are suggested.