The Wind Wake Effect on Pool Fires in Storage Tank Farms

Pool fires from accidental releases are a major concern in storage tank farms. Quite often the fire fighting can take days and the escalation to the neighbouring tanks is a cumulative hazard. Additionally, pool fires are very sensible to the wind speed and wind direction. It turns out however, that in storage tank farms, the separation of the boundary layer of the flow field in the viscous layer of the solid walls of the tanks lead to zones of negative pressure gradient. Therefore, the recirculation zones and the back flow in the wake of the tanks play a very important role in the dynamics of the fire flames. Traditional solid flame models are not able to capture such behaviour. The current study investigates via computational fluid dynamics (CFD) how the intermittent and irregular flow at the wake of the storage tanks influences the heat flux received by the neighbouring tanks which are not under fire. The proposed methodology can be used in the deluge design of the tank farms. The results obtained by CFD are also important to help the fire brigade when controlling accidental fire scenarios in storage tank farms. The results can be easily coupled to a solid mechanics tool to calculate how the tank material respond to the heat dose and what is the likelihood of collapse based on the leak frequency and meteorological data.