Gradient increasing-angle Tesla minichannel cold plate for battery thermal management: numerical investigation and experimental verification

Lithium-ion batteries generate significant heat during high-rate operation, which leads to elevated temperature and non-uniform temperature distribution. Liquid cooling is widely used in battery thermal management systems (BTMS) due to its high heat transfer efficiency. However, conventional straight channels exhibit limited flow disturbance and insufficient heat transfer performance. This study proposes an incrementally angled Tesla minichannel structure. The channel angle is gradually increased along the flow direction to balance flow resistance and heat transfer enhancement. Numerical simulations are conducted to analyze the thermal-hydraulic performance of straight channels, fixed-angle Tesla channels, and Increasing-angle channel Tesla channels. The results show that the Tesla structure enhances flow disturbance and improves heat transfer by inducing vortex and secondary flow. The proposed incrementally angled Tesla channel further improves performance. Compared with the straight-channel baseline, the 6° − 20° configuration reduces the maximum battery temperature from 313.53 K to 311.00 K, corresponding to an absolute decrease of 2.53 K. Relative to the coolant inlet temperature of 295.15 K, the maximum temperature rise is reduced by 13.76%, and the temperature difference reduces from 8.30 K to 6.69 K compared with the straight channel, representing a reduction of 19.40%. The pressure drop increases slightly from 1165.55 Pa to 1231.65 Pa, corresponding to an increase of 5.67%, while the performance evaluation criterion (PEC) reaches 1.22. It demonstrates that the Increasing-angle channel Tesla structure achieves a better balance between heat transfer enhancement and flow resistance. This design provides an effective approach for liquid-cooled battery thermal management systems.