Natural convection in a partially heated square cavity with an inner square block

In this paper, we steady natural convection in a discrete heat transfer and the effect of Rayleigh number in a two- dimensional square enclosure with an inner square block. The present problem taken by three different cases were containing on the partially heated which left vertical wall maintained at high temperature Th(Th > Tc). The right vertical wall considered at Tc and other horizontal walls and the inner square block should be thermally insulated. The mathematical model considered as mass, momentum and energy equation solved to using the simple algorithm by Finite Volume Method (FVM) on a flounder grid system consisting of modified Alternating Direction Implicit Method (ADIM) which are used to solve vorticity-stream function formulation.This result found that the streamlines and isotherms achieved a maximum for the distribution of partial heater and also increasing Rayleigh number.