Mixed convection in rectangular cavities at various aspect ratios with moving isothermal sidewalls and constant flux heat source on the bottom wall

Abstract

Mixed convection heat transfer in a two-dimensional rectangular cavity with constant heat flux from partially heated bottom wall while the isothermal sidewalls are moving in the vertical direction is studied numerically. The enclosure represents a practical system such as an air-cooled electronic device, where cooling from the sides is expected to be an efficient electronic cooling option. The heat source represents a heater or an electronic component located at the bottom in such an enclosure. Several different values of the heat source length, the aspect ratio of the cavity, as well as symmetric and asymmetric placement of the heat source are considered. All computations are done for a range of Richardson number from 0.1 to 10. The influence of the Richardson number, heat source length, placement of the heat source, and aspect ratio of the cavity, on the maximum temperature and the Nusselt number at the heat source surface is investigated. Results are presented in the form of streamline and isotherm plots as well as the variation of the maximum temperature and Nusselt number at the heat source surface under different conditions. The pressure–velocity coupling in the governing equations is achieved using the well-known SIMPLE method for numerical computation. The computational procedure is based on finite volume collocated mesh. The linear algebraic system of equations is solved sequentially using the strongly implicit procedure (SIP).