2016 年 41 巻 4 号 p. 269-277
Recent studies on hydrogen gas release and dispersion are overviewed in connection with safety of widespread utilization of hydrogen as an energy carrier. Full scale experiments on release of high pressure hydrogen gas under the supposition of accidental leakage in hydrogen fueling station were performed in the open field, in which the data of dispersion characteristics of flammable gas cloud were obtained. Computational studies on dispersion of hydrogen in a tunnel or an underpass on the assumption of accidental release from high pressure gas cylinders of fuel cell vehicle or bus were performed and showed the diffusion and decay of flammable gas cloud by effective ventilation. Regarding dispersion of hydrogen released in private garage or confined spaces, various types of experiments and analytical studies using different versatile CFD codes and different turbulence models were performed to analyze the flow of flammable gas and the effect of vent.