Sprinkler Protection of Storage under Sloped Ceilings—Part 1: Numerical Modeling

In the present study, a numerical model-based investigation has been conducted to understand the automatic sprinkler protection challenges associated with sloped ceilings. The modeling study has been conducted using the computational fluid dynamics (CFD) code FireFOAM. Ceiling jets resulting from growing fires on a 3-tier high cartoned unexpanded plastic (CUP) rack-storage commodity have been simulated to investigate the effect of ceiling slope and obstruction (purlin) depth on sprinkler activations. For quick-response, ordinary temperature-rated sprinklers, simulation results show that for the fire source being evaluated, ceilings with \(\le 18^\circ\) inclination and purlin depths of \(\le 0.2\) m have similar activation times and patterns as non-sloped ceiling for the four sprinklers immediately adjacent to the fire source. Spray transport simulations have also been conducted to evaluate the effect of ceiling slope and sprinkler installation orientations on water flux distributions. Results indicated that the sprinkler deflector parallel to the floor is a preferable orientation.