CFD benchmark on hydrogen release and dispersion in confined, naturally ventilated space with one vent

A CFD benchmark was performed within the HyIndoor project, to study hydrogen releaseand dispersion in a confined space with natural ventilation and one vent. Three experiments,performed earlier by CEA at their GAMELAN 1 m3 facility, were considered for thisbenchmark. In all three tests helium (instead of hydrogen for safety reasons) was releasedvertically upwards at 60 NL/min from a 20 mm orifice near the centre of the enclosure. Adifferent vent size was used for each test. Three HyIndoor partners (JRC, NCSRD and UU)participated in the benchmark, with three different CFD codes, (ANSYS Fluent, ADREA-HFand ANSYS CFX) and three different turbulence models respectively (transitional SST,standard k-ε, dynamic Smagorinski LES). In general, good agreement was found betweenpredicted and measured helium concentrations. However, in the case of the vent with thesmallest vertical extension (vent c) all predictions overestimate the concentration at thelower part of the enclosure at steady state.