Numerical Study on Shockwave Attenuation by Water Mist in Confined Spaces

Hydrogen safety has become the first consideration, especially after fuel cell automobiles were pushed into commercial auto market. Tunnels are important parts of traffic infrastructure featured in confinement or semi-confinement. Hydrogen detonation is a potential accident scenario while hydrogen fuel cell vehicles are operated in a traffic tunnel with a confined space. Pressure shockwaves are mostly produced by hydrogen detonation and propagate along the tunnel. As a designed safety measure, water mist injection is hopefully to mitigate the pressure loads of such shocks. To model the interaction between shockwaves and water droplets, a droplet breakup model has been developed for the COM3D code, which is a highly validated three-dimensional hydrogen explosion simulation code. By using the model, the hydrogen detonation shockwave propagation in confined volumes is simulated in the study. The attenuation effects of water mist on the pressure shocks in the simulations are elaborated and discussed based on the simulation results.