LES modelling of hydrogen release and accumulation within a non-ventilated ambient pressure garage using the ADREA-HF CFD code

Computational Fluid Dynamics (CFD) has already proven to be a powerful tool to study the hydrogen dispersion and help in the hydrogen safety assessment. In this work, the Large Eddy Simulation (LES) recently incorporated into the ADREA-HF CFD code is evaluated against the INERIS-6C experiment of hydrogen leakage in a supposed garage, which provides detailed experimental measurements, visualization of the flow and availability of previous CFD results from various institutions (HySafe SBEP-V3). The short-term evolution of the hydrogen concentrations in this confined space is examined and comparison with experimental data is provided, along with comments about the ability of LES to capture the transient phenomena occurring during hydrogen dispersion. The influence of the value of the Smagorinsky constant on the resolved and on the unresolved turbulence is also presented. Furthermore, the renormalization group (RNG) LES methodology is also tested and its behaviour in both highly-turbulent and less-turbulent parts of the flow is highlighted.

► ADREA-HF LES is evaluated against experimental data of hydrogen leak in garage. ► LES captures the unsteady character of the flow and compares well with experiment. ► Sensitivity study on Smagorinsky constant reveals preferred value around 0.10-0.12. ► In high turbulence areas, excessive SGS is shown to severely damp resolved turbulence. ► RNG-LES methodology is also tested and its advantages shown in practice.