Energy Efficiency Analysis of Coupled Thermal Radiation and Free Convection within a Square Enclosure with Internal Heating

Abstract

This study explores the simultaneous impact of thermal radiation and free convection within a square cavity featuring internal heating. The walls are consistently held at a stable temperature through isothermal cooling, while an internal heat source sustains a consistently higher temperature. The radiation component is characterized by employing the FT40 discrete-ordinate approximation in conjunction with the statistical narrow-band correlated-k method (SNBcK). The primary focus lies in discerning the influences of radiation on both flow patterns and heat transfer. Particular emphasis is placed on investigating energy efficiency and its correlations with key governing parameters, including the heat source temperature, wall emissivity, and the size and placement of the heater. A noteworthy revelation from this analysis is the substantial impact of radiation on the acceleration of vortices, leading to a homogenizing impact on temperature distributions. Additionally, it is observed that the highest level of energy efficiency is realized by siting the heater at the central lower section of the enclosure.