Transient combined volumetric radiation and free convection in a chamber with a hollow heat-generating solid body

Abstract

The present investigation numerically scrutinizes the generated heat removal in some electronic devices both to prevent overcooling and keep the uniformity of environmental temperature with the goal of increasing the operating life. For this purpose, conjugate combined convective-radiative energy transport is studied in a square shape and tilted chamber containing a hollow square shell solid block as a second cavity with a uniform heat generation which is placed in the central zone of the chamber. The finite-difference method is employed to solve the governing equations. Also, for considering the gas radiation effect, the radiating computations are based on the numerical solution of the radiation transfer equation and solved by the discrete ordinate method. The effects of Plank number, the inclination angle of the cavity, the gas optical thickness, and surface emissivity of the boundaries on the flow and the thermal characteristics of the system and on controlling the working temperature near to the optimal set point is studied. The results show that by using the radiating filling gas with low optical thickness, high Plank number, and applying higher surface emissivity, more cooling rate can be achieved at the transient period up to 38%, 85%, and 50% respectively.