Studies on thermal responses of sprinkler heads in atrium buildings with fire field models

Sprinklers are commonly sited in the high headspace atrium of a building where such systems are required. It was questioned whether sprinkler heads would be activated in the case of a fire. A fire modelling technique was applied to estimate the actuation time of sprinkler heads located in the atrium ceiling. The response time of sprinkler heads to a fire in a shop at a high level adjacent to the atrium roof was calculated. A self-developed FORTRAN code together with the CFD model CFX4.2 were used to simulate the atrium fire environment. The standard k-ε model was used with two key parameters, diffusion coefficient and effective Prandtl number tuned. A comparison with some experiments reported in the literature was made. Satisfactory agreement between the predicted and measured results was found.