Abstract
In this paper, two methods of numerical solution of the equations for air flow are described. One is vorticity method and the other is MAC method. Besides, the solutions of pressure in vorticity method and vector potential in MAC method are explained. Two and three dimensional models for laminar thermal convection in an enclosure are simulated by means of these two methods. The results of computations are displayed as distributions of streamline, temperature and pressure in the two dimensional model and the sections of three dimensional one. Two and three dimensional models as well as these two methods are compared on variables, equations, computation time (CPU time) and the results in order to make these properties clear. Vorticity method is superior to MAC method in CPU time and convergence condition. While, in the case of three dimensional analysis, MAC method is easy to carry out because of its brevity of equations and boundary conditions. The solution of pressure in vorticity method is tend to be influenced by temperature on the boundary. Pressure should be solved by MAC method if pressure is used as inlet and outlet boundary condition, or time-dependent solution of pressure is needed.
