Cooling in a Cavity with Combined Mixed Convection‑Surface Radiation

Abstract

is study aims to identify the optimal configuration for the cooling process within a cavity by analyzing entropy generation, cooling efficiency, and average total temperature using the Lattice Boltzmann Method. In this setup, the upper and lower walls of the cavity are insulated, while the left and right walls are maintained at constant temperatures. The flow was modeled as two-dimensional, laminar, and steady-state, with all internal surfaces treated as opaque, diffuse, and gray. The momentum and energy equations were solved through the Lattice Boltzmann method, while radiation effects were addressed using the net radiation method. Reynolds numbers of 100, 200, 300, and 400, along with surface emissivities of 0, 0.5, 0.8, and 1, were tested for each configuration, with a constant Richardson number of 1. The results demonstrate that both flow and temperature fields are significantly influenced by configuration and Reynolds number, whereas surface emissivity predominantly affects only the temperature field. Furthermore, increasing surface emissivity enhances the cooling process within the system. Analyzing entropy generation, cooling efficiency, and average total temperature across all configurations reveals that configurations B and F are optimal for cooling. Additionally, the impact of varying Richardson numbers was investigated for configuration B, revealing that an increase in Richardson number leads to reduced entropy generation and improved cooling efficiency