A PARAMETRIC STUDY OF RADIATIVE HEAT TRANSFER IN AN INDUSTRIAL COMBUSTOR OF WOOD CARBONIZATION FUMES Mohamed Ammar Abbassi, Kamel Halouani, and Mohamed-Sassi Radhouani Micro Electro Thermal Systems, IPEIS, Sfax, Tunisia Habib Farhat IPEIM, Monastir, Tunisia Radiative heat transfer is investigated numerically for an industrial combustor of wood carbonization fumes. The combustor has a complex geometry. The finite–volume method (FVM) is applied to study radiative heat transfer in conjunction with the weighted sum of gray gases (WSGG) model of Kim and Song as a non-gray-gas model. The blocked-off- region procedure is applied to treat the geometric irregularities. The reliability of this model, for a complex geometry filled with a semitransparent medium and a regular geometry containing water vapor, is analyzed by comparing its predictions with the exact solution and the Monte Carlo technique associated with the statistical narrow band (SNB) model. Good agreement with benchmarks is found. The extension of this model to a mixture of CO 2 ,H 2 O, particles, and soot particles (confined in a complex geometry) is made. The effects of soot volume fraction, partial pressure ratio, particle concentration, and thermal nonequilibrium on the inner wall radiative heat flux of the combustor are presented. INTRODUCTION Several new methods have been investigated in the last few decades for model- ing efficiently the radiative heat transfer in a real participating gas. Among them, the finite–volume method (FVM), introduced by Raithby and Chui [1], offers a good compromise between accuracy and computing time and can be easily incorporated in computational fluid mechanics codes which involve radiating gases at high tem- peratures. However, it suffers from ray effect and false scattering. Consequently, alternative numerical schemes for practical applications have been presented by many investigators such as Chai et al. [2] and Liu and Becker [3]. The FVM was either applied for regular or complex geometries. In the case of irregular geometries it was developed with the spatial multiblock procedure [4]. The body-fitted grids technique used by Chui and Raithby [5] is inadequate and some- times impossible to generate in some engineering problems. The unstructured grid divides the physical domain into a finite number of unstructured triangular and Received 25 June 2004; accepted 18 October 2004. Address correspondence to Kamel Halouani, Micro Electro Thermal Systems (METS), IPEIS, Route Menzel Chaker Km 0.5, BP: 805-3000, Sfax, Tunisia. E-mail: kamel.halouani@ipeis.rnu.tn 825 Numerical Heat Transfer, Part A, 47: 825–847, 2005 Copyright # Taylor & Francis Inc. ISSN: 1040-7782 print=1521-0634 online DOI: 10.1080/10407780590916995