MIXED CONVECTIVE COOLING OF A RECTANGULAR CAVITY WITH INLET AND EXIT OPENINGS ON DIFFERENTIALLY HEATED SIDE WALLS

Abstract

A numerical study is conducted to investigate mixed convective cooling of a two-dimensional rectangular cavity with differentially heated side walls. The horizontal walls are assumed to be adiabatic. Cold fluid is blown into the cavity from an inlet in the side wall of the cavity and is exited through an outlet in the opposite side wall. This configuration of mixed convective heat transfer has application in building energy systems, cooling of electronic circuit boards, and solar collectors, among others. The objective of the research is to optimize the relative locations of inlet and outlet in order to have most effective cooling in the core of the cavity by maximizing the heat-removal rate and reducing the overall temperature in the cavity. Various placement configurations of the inlet and outlet are examined for a range of Reynolds number and Richardson number. For a given Reynolds number, the Richardson number is varied from 0, which represents pure forced convection, to 10, which implies a dominant buoyancy effect. Injection of air at the top and bottom of hot and cold walls is compared and the results are presented in the form of isotherms, streamlines, cooling efficiency, average temperature, and local and average Nusselt number at the hot wall. It is observed that maximum cooling effectiveness is achieved if the inlet is kept near the bottom of the cold wall while the outlet is placed near the top of the hot wall.