Simulation of an experimental compartment fire by CFD

Abstract

This paper analyses the experimental results, obtained in a compartment fire experiment [Kumar R. Studies on compartment fires. Ph.D. thesis. Indian Institute of Technology, Roorkee, 2004], by using CFD modelling. Experiments were conducted in a compartment by burning methanol as a fuel. Temperatures vs. time were recorded at 11 different locations in the compartment for three sizes of fires. CFX-5.7.1 [CFX 5.7.1, ANSYS, Inc., 275 Technology Drive, Canonsburg, PA 15317, 2005] is the software package used for the analysis. Earlier CFX has been validated with the experimental data of Steckler et al. [NBSIR 82-2520. National Bureau of Standards, Washington, DC, 1982] on compartment fires. However, this validation was for steady fires. In the present work validation has been done for growing fires during transient period. The predictions of temperatures with time at selected locations are in good agreement with the experimental results. Further the predicted profile of horizontal component of velocity at the door centreline is in agreement with usual assumption, made in zone models that the neutral plane exists at about the door mid height. Above this plane the hot gases leave the compartment, while below it fresh air enters into the compartment from the outside. It is our view that the CFX, though being general purpose CFD software, may be applied to complex fire scenarios for the analysis, and developing fire safety regulations.