Thermal performance enhancement and prediction of narrow liquid cooling channel for battery thermal management

Abstract A novel heat transfer device for narrow space was proposed to meet high power battery heat dissipation. Based on the battery heat generation data, the heat transfer enhancement mechanism of the secondary flow pattern is studied. Then establish the general heat transfer correlation for this liquid-cooled structure with a specific aspect ratio. The results show that the channel with rib angle of 90° has higher Nu as well as ƒ and can achieve the same heat transfer performance with smaller flow rate. This is due to its transition flow pattern of twist-tape vortex and stagnant vortex, which can enhance the contact heat transfer performance of mainstream cold fluid while inhibiting the growth of boundary layer. The increase in rib number gradually decreases the gain of Nu with a minimum increment of less than 1%; while ƒ almost gradually increases with a common difference of 0.05. From the perspective of heat transfer and energy saving, increasing rib number does not essentially improve the heat transfer performance. Because the flow field at different rib number is just a mapping of the complete flow field at the corresponding length. Based on the above data, for the flat channel with aspect ratio of 10:3 in narrow space, the second-order general heat transfer correlation for different hydraulic diameter is established considering the Re, dynamic viscosity, rib angle and rib number. Finally, the coefficient of determination (R2) of the correlation is 0.9973, which can provide guidance for battery thermal management engineering applications.