Effects of Fractal Cantor Structured Hot Surface on Thermal Management System

Phase change material (PCM) has been implemented in thermal management systems. However, the heterogeneous interface between hot surface and PCM may lead to non-negligible thermal slip, resulting in alleviated energy storage efficiency. This study investigates the heat transfer performance of PCM at fractal Cantor structured hot surfaces. A total enthalpy-based lattice Boltzmann method is developed to study the pore-scale solid-liquid phase change problems with the natural convection. The effects of fractal dimension, Ste and gravity on heat transfer performance are analyzed. Meanwhile, the local velocity distribution and interfacial heat transfer performance are evaluated and regarded as the criteria. Results show that the presented results are in good agreement with experimental results. Fractal Cantor structure can significantly reduce the average thermal slip length, thus enhancing the heat transfer between heat source and PCM. As the fractal dimension increases, the localized convection can be gradually revolutionized into widespread convection, resulting in a more uniform melt-front evolution along the horizontal direction. As a result, the total melting time can be minimized by 5% with the fractal dimension of 3. Elevating Ste and gravity can significantly increase the flow rate of liquid PCM, which leads to enhanced convective heat transfer strength. Between them, gravitational acceleration yields the most significant enhancement in heat transfer performance.