Numerical and experimental study of heat transfer in a cubic cavity with a PCM in a vertical heated wall

Abstract

In this work, a transient numerical and experimental study is presented, focused on describing the heat transfer in a cavity filled with air, which has one vertical wall with a phase change material (PCM). The wall with PCM was exposed to constant heat flux, whereas the opposite vertical wall was kept at a constant temperature. For the theoretical study, a model for heat transfer was proposed and solved using computational fluid dynamics software. The enthalpy method was used to simulate the phase change in the PCM. For the experimental study, five temperature profiles were obtained for air, one for PCM, and at different points of shared wall between PCM and air. A comparison was made, between, experimental and numerical data, to determine the predictive capacity of the model. Besides, numerical results of the liquid fraction in the PCM were compared with data reported in the specialized literature. It was found that the enthalpy method was adequate to study proposed in this study. The numerical temperature fields and flow patterns in the air were analyzed, as well as the evolution of the liquid fraction in the PCM. With the validated model, a parametric study was conducted to quantify the effect of Rayleigh number and PCM thickness on Nusselt number and the average air temperature. It was found that the use of the PCM decreased the heat transfer to the air. The comparison with the case without PCM indicated that Nusselt number values reduced between 66.80 and 75.47%.