Passive Thermal Management of Electronic Devices in a Molten Phase Change Material-Filled Semi-elliptical Cavity

Electronic device thermal management systems use phase change materials with high latent heat capacity. This numerical investigation using finite volume method aims to determine the optimum geometrical parameters of a molten phase change materials-filled semi-elliptical heat sink cavity to maintain the electronic device at lowest temperature. The cavity’s relative width and height are varied along with device’s position and aspect ratio. The results reveal that the cavity with relative width equal to 1 ensures the lowest device temperature up to Rayleigh number 105. For higher Rayleigh numbers, the cavity with relative width equal to 3 is more potent in lowering the device temperature, with a maximum 11.87% enhancement in Nusselt number. Similarly, the cavity with relative height equal to 0.5 elevates Nusselt number by 20.37% and 15.74% at Rayleigh number equal to 105 and 107, respectively. The cavity thus identified is semi-circular-shaped and offset device positions are not preferable. Maximum Nusselt number is noted for device aspect ratio less than 1. At low Rayleigh number, the device temperature is lowest under the convective boundary condition corresponding to Biot number equal to 0.1. In contrast, at peak Rayleigh number the convective conditions with Biot number equal to 1 shows superior performance.