Large Eddy Simulation of Sprinkler Interaction with a Fire Ceiling Jet

Abstract

A large eddy simulation (LES) CFD model is used to predict water sprinkler spray interaction with a fire environment. The emphasis is on computing gas temperatures and velocities induced by sprinkler discharge onto the ceiling jet flow. Results are presented for two different water discharge rates, in addition to simulation of free-burning fire. Extensive variation of physical and numerical parameters is performed to investigate the robustness of the predictions. The results of the computations compare favorably to measurements from full-scale fire tests reported in the literature, indicating good accuracy of LES approach in application to practical fire design problems. Results are also compared with the earlier treatment of the same problem using the Reynolds-averaged Navier–Stokes (RANS) approach.

Keywords:

• Fire
• Large eddy simulation
• Sprinkler

Acknowledgments

The first author would like to thank Prof. Haukur Ingasson of Lund University and Dr. Kevin McGrattan of NIST for their helpful comments and suggestions during this work. The first author is especially grateful to Mr. Andy Pollak of Universities Ireland, Mr. Stephen Brady and Mr. Hugh O'Neill of Dublin Fire Brigade, and Ms. Maria Finegan of SAFE Fire and Risk Engineering for their support. Finally, both authors are very grateful to Miss Ciara Fitzpatrick for editing and proofreading the final manuscript.