Influence of Draft Curtains on Sprinkler Activation - Comparison of Three Different Models

Abstract

This article investigates the importance of using draft curtains to obtain faster sprinkler activation with three different models-two computational fluid dynamics (CFD) models (CFX 4.4 and fire dynamics simulator (FDS) 4.07) and a zone model (Argos) containing a ceiling-jet formula - for an actual scenario in an entertainment center in Denmark. It is found that a draft curtain has some effect on sprinkler activation, reducing activation time from 8% to 15%, depending on the model implemented. The positions of the sprinklers with in the vertical computational grid of the CFD simulations have a greater influence on the activation of the sprinkler, where FDS is more sensitive than CFX. It is confirmed that heat transfer from the ceiling jet to the ceiling has little influence on the results. The zone model with a ceiling-jet formula gives 10—20% slower sprinkler activation than the CFD results when the sprinkler is close to the ceiling, but is still considered very useful in view of the faster calculation time.