ABSTRACT

A numerical analysis of natural convection in air-filled, 2-D square enclosures, with imposed uniform heat flux at a portion of the bottom wall and uniform temperature at the top and side walls, is carried out. The study is conducted for the laminar flow regime through a specifically developed numerical code based on the SIMPLE algorithm, which is used for the solution of the mass, momentum, and energy transfer governing equations. Simulations are performed for several values of the thermal-flux Rayleigh number as well as different sizes and positions of the heated portion of the bottom endwall, whose influence upon the flow patterns, the temperature distributions and the heat transfer rates are pointed out and discussed. Heat transfer results are also reported in terms of dimensionless correlation-equations. The occurrence of steady-periodic solutions, which arise for intermediate sizes of the heated portion of the bottom wall, is then documented.