not-yet-known not-yet-known not-yet-known unknown 2. Design and methodology : 2.1. Geometric model description : The studied models are designed using SolidWorks 3-D CAD design software. Three types of fins (square, triangular, and circular) are used. Heat sinks and fins are made from aluminum, and fins are arranged in inline configurations. All the heat sinks have the same length of 55 mm and width of 35 mm. Two different heights (16 mm and 10 mm) of fins are evaluated. There is also a variation in the number of fins explored in this study. For an 84-pin fin heat sink, the spacing is 1.1 mm, whereas for 45 fins, the spacing is 2.3 mm. The length or diameter of the fins is the same as 3 mm. Figure-1 shows the schematic diagram of all the heat sink models. [insert Figure-1 here] 2.2. PCM types : Paraffin wax, stearic acid and polyethylene glycol are used as PCMs in this study. PCM generally changes its phases between solid and liquid to store and release thermal energy. So, both the solid and liquid characteristics of the PCMs should be considered. Table-1 shows the specific parameters of the PCMs in the solid phase, and Table-2 shows the same properties in the liquid state.