Journal of Applied Sciences1812-56541812-5662Asian Network for Scientific Information10.3923/jas.2006.2866.2874MehdaouiR.M. ElmirB. DraouiO. ImineA. Mojtabi122006614The objective of this research is the study the influence of aspect ratio A_{1} of fluid portion compared to the height of cavity, on the natural convection in a partially porous enclosure. A cylindrical heat source maintained at a uniform temperature is introduced into porous portion. The equations which describe the thermal transfer and the hydrodynamic flow are described by the Navier-Stokes equations modified by using the extension of Darcy-Brinkman and the energy equation. The results obtained are in the form of isotherm`s distribution, stream`s functions, the local and the average Nusselt numbers and the pressure. Correlations between these parameters and the aspect ratio are considered.]]>Bejan, A.,1979Bejan, A. and K.R. Khair,1985Bejan, A. and A.D. Kraus,2003Bejan, A., I. Dincer, S. Lorente, A.F. Miguel and A.H.V. Reis,2004Cheng, P.,1978Combarous, M. and S.A. Bories,1977Hickox, C.E.,1981Ingham, D.B., A. Bejan, E. Mamut and I. Pop,2004Ingham, D.B. and I. Pop,2005Lauriat, G. and V. Prasad,1987Masuouka, T., Y. Yokote and T. Katsuhara,1981Nield, D.A.,1991Patankar, S.V., 1980Polikakos, D. and A. Bejan,1983Pop, I. and D.B. Ingham,2001Tanmay, B., S. Roy, T. Paul and I. Pop,2006Tong, T.W. and E. Subramanian,1985Vafai, K.,2000Weber, J.E.,1975