Résumé:
We propose in this work, the numerical study of the natural convection laminar and permanent, in rectangular enclosures whose vertical
walls are active and horizontal one are adiabatic. The active walls are heated and cooled by sinusoidal temperature profiles, three cases of
heating and cooling have been considered. Steady state heat transfer by laminar natural convection has been studied numerically by solving
equations of mass, momentum and energy. The enclosure is filled by a Newtonian and incompressible fluid. The number of Prandtl is fixed
at 0.702 (case of the air), but the number of Rayleigh varies. By using the approximation of Boussinesq and the vorticity-stream function
formulation, the flow is modelled by the differential equations with the derivative partial.
A computer code was developed, it uses finite volumes, for the discretization of the equations, and in order to show its reliability, we
compare results resulting from the latter with other similar results existing in the literature, and we examine the effect of the Rayleigh
number, and the parietal thermal conditions, on the results obtained, that it is qualitatively or quantitatively
