Transient Analysis of Phase Change Material for the Cooling of Discrete Heat Sources Under Mixed Convection

Abstract

The paper deals with the transient numerical analysis of phase change material (Paraffin wax) used for the cooling of seven non-identical protruding discrete heat sources (Aluminium) mounted on a substrate (Bakelite) board under mixed convection. The phase change materials (PCMs) are filled inside the protrude mini-channels (fabricated on the substrate board) and the heat sources are placed on the minichannels.Transient heat transfer analysis is carried out using ANSYS Fluent to predict the temperature distribution of these heat sources. The melt fraction of the Paraffin wax is reported for both the charging (heating) and discharging (cooling) zone with respect to time. The results are validated with the existing numerical models. The study is extended using different PCMs (n-eicosane (Tm - 36.5°C), paraffin wax (Tm–43 to 49.5°C) and RT-54 (Tm -54°C)) to study the cooling characteristics of heat sources. It is seen that there is a temperature drop of 3 - 6°C for the heat sources using the PCM. Thus it confirms that PCM can be used for better thermal management of heat sources.The study is also extended to determine the volume fraction of PCM inside the mini-channels and is seen that the mini-channels with 100% PCM volume shows the maximum temperature drop from the heat sources.