Numerical simulation of three-dimensional transient cooling application on a portable electronic device using phase change material

A numerical transient three-dimensional heat transfer investigation of a hybrid PCM based heat sink cooling technique was presented in this study. Thermal energy was transferred to the calculation domain through the base of heat sink. The n-eicosane was adopted inside the heat sink cavity as the Phase Change Material (PCM) for latent heat storage. The governing equations were solved numerically by a control-volume-based finite-difference method using a power law discretization scheme to describe the heat transfer in the simulated system. The melting mushy zone, around the phase change boundary, was predicted by an enthalpy-porosity approach. In addition, the PCM-air VOF (Volume of Fluid) model was adapted to solve PCM-air gap boundary which was caused by PCM’s volume expansion for the difference of variable density.In this study, numerical computations have been conducted for various power levels (2 W–4 W), different orientations (vertical/horizontal/slanted), and charge and discharge modes. Different time steps (0.03/0.05/0.07 s) were discussed in the literature for transient accuracy as well. The developed theoretical model was validated by comparing numerical predictions with the available experimental data by Fok et al. [9]. The numerical results showed that the temperatures were reasonably predicted with a maximum discrepancy within 10.2%.

► Electronic device cooling use phase change materials.
► N-eicosane is adapted as phase change materials.
► Two phase melting problem using VOF modeling approach.
► Three dimension and transient temperatures prediction error is within 10.2%.
► Hybrid PCM-heat sink system provides stable operation temperature.