Combustion and Flame 153 (2008) 499–509 www.elsevier.com/locate/combustflame Fire dynamics simulations of a one-meter diameter methane fire Y. Xin a , S.A. Filatyev a,∗ , K. Biswas a , J.P. Gore a , R.G. Rehm b , H.R. Baum b a School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907, USA b National Institute of Standards and Technology, Gaithersburg, MD20899, USA Received 2 April 2007; received in revised form 19 December 2007; accepted 15 January 2008 Abstract A one-meter diameter-methane fire was simulated to validate a fire dynamics simulation code for large-scale fires. A uniform grid size of 2.5 cm in the entire computational domain is used. Therefore, only large-scale motions of the fire are resolved. The subgrid-scale heat release is modeled using a mixture-fraction-based combustion model. The radiative heat loss is computed using two methods: a fixed radiative fraction method and a finite volume method. The computed puffing cycle frequency is affected very weakly by the radiation heat loss. The vertical velocity magnitudes without considering radiation heat loss are about 15% higher, particularly at locations farther away from the burner exit. Good agreement between the predictions and the recent data from Tieszen and co-workers at Sandia National Laboratory confirms the feasibility of fire dynamics simulations of relatively large fires.  2008 The Combustion Institute. Published by Elsevier Inc. All rights reserved. Keywords: Fire dynamics; Numerical simulation; Turbulent buoyant flames; Combustion models 1. Introduction Numerical simulation of fires is important because of the limitations and difficulties associated with fire experiments, particularly for large-scale fires. Fire simulations have been developed from zone to field model over the years. Recently, fire dynamics simu- lation code (FDS) has been shown to be promising in predictions of laboratory-scale buoyant fires [1,2]. Excellent agreement between predicted and mea- sured instantaneous and time-averaged flow fields of a laboratory-scale nonreacting helium plume and a 7.1- * Corresponding author. Fax: +1 765 494 0530. E-mail address: sergei.a.filatyev@conocophillips.com (S.A. Filatyev). cm-diameter buoyant methane flame was achieved using the Lagrangian thermal element combustion model with carefully selected domain and grid size. Recently, similar agreement for the fire flow field, mixture fractions, and temperatures was obtained us- ing a mixture-fraction-based combustion model [2]. The limitations of grid and domain effects in the thermal element model are overcome by the mixture- fraction-based combustion model. However, whether the model can be extended to large-scale fires is still question. To answer this question, in the present work, a 1-m methane-fueled buoyant pool fire was simulated using the mixture- fraction-based combustion model. A fixed-radiative- heat-loss method and a finite-volume method were used to treat the effects of radiation. The computa- 0010-2180/$ – see front matter  2008 The Combustion Institute. Published by Elsevier Inc. All rights reserved. doi:10.1016/j.combustflame.2008.01.013