Passive flow control of phase change material using baffle for convection enhancement

The aim of this research is to enhance convective heat transfer within phase change materials (PCM) using baffles on a vertical wall. PCMs have major drawbacks such as low thermal conductivity, high viscosity, and limited natural convection. To address these issues, we investigated a passive approach to dissipate the heat with baffles. The visualization experiments including shadowgraphy and particle image velocimetry (PIV) were carried out to compare between the case with baffle (WB) and the case without baffle (NB). The baffles are horizontal plates that divide the vertical wall into zones and are designed to have a gap near the heat source to facilitate filling of the PCM and absorb volume changes. The average temperature difference in the horizontal direction was lowered by 39.68 % due to the presence of the baffles. And, the temperature difference in the vertical direction was reduced by 50 % in the WB instance against the NB case. Furthermore, when comparing WB with NB, the convection coefficient increased by up to 28 %, 34 % and 27 % at the heat power levels of 4, 6, and 8 W, respectively. As a result, the baffles on the vertical wall improved convective heat transfer performance by changing the internal flow pattern.