Progress in Computational Fluid Dynamics, Vol. 7, No. 5, 2007 237 Copyright © 2007 Inderscience Enterprises Ltd. Entropy generation in double diffusive convection in presence of the Soret effect N. Hidouri Engineers National School of Gabès, Gabès University, Avenue of Omar Ibn El Khattab, 6029 Gabès, Tunisia Fax: +216 75 392 190 E-mail: n_hidouri@yahoo.com M. Magherbi* High Institute of Applied Sciences and Technology, Gabès University, Avenue of Omar Ibn El Khattab, 6029 Gabès, Tunisia Fax: +216 75 392 190 E-mail: magherbim@yahoo.fr *Corresponding author H. Abbassi Faculty of Sciences, Sfax University, 3018 Sfax, Tunisia E-mail: Hassen.Abbassi@fss.rnu.tn A. Ben Brahim Engineers National School of Gabès, Gabès University, Avenue of Omar Ibn El Khattab, 6029 Gabès, Tunisia Fax: +216 75 392 190 E-mail: Ammar.BenBrahim@enig.rnu.tn Abstract: Influence of the Soret effect on entropy generation in a square cavity filled with a binary gas mixture in double diffusive convection is numerically studied. It was found that entropy generation increases with the increase of thermal diffusion and buoyancy ratios for fixed thermal Grashof number. Total irreversibility takes a minimum value at a special buoyancy ratio ranging between –1 and 0. Soret effect causes the increase of total irreversibility by more than 50% at higher values of thermal Grashof number and buoyancy ratio. More details of the irreversibilities localisation are discussed. Keywords: cavity; heat and mass transfer; entropy generation; irreversible processes; numerical methods; Soret effect. Reference to this paper should be made as follows: Hidouri, N., Magherbi, M., Abbassi, H. and Ben Brahim, A. (2007) ‘Entropy generation in double diffusive convection in presence of the Soret effect’, Progress in Computational Fluid Dynamics, Vol. 7, No. 5, pp.237–246. Biographical notes: Nejib Hidouri is a PhD student in Chemical and Process Engineering in the Engineers National School Gabès, Tunisia and a member of the research unit of applied thermodynamics in the same school. Mourad Magherbi holds a PhD in Physics and is currently an Associate Professor and Head of the Civil Engineering Department at the High Institute of Applied Sciences and Technology of Gabès, Tunisia. He is a member of the research unit of applied thermodynamics in the National School of Engineers of Gabès, Tunisia. Some of his selected publications are: Magherbi et al. (2003, 2006). Hassen Abbassi holds a PhD in Physics and is currently an Associate Professor at the Sciences Faculty of the Sfax University, Tunisia. Some of his selected publications are: Abbassi et al. (2003a, 2003b).