Optimization and thermal characterization of a new liquid-cooled plate with branching channels of fractal geometry

In order to improve the heat transfer effect of the liquid-cooled plate with the traditional straight channel, 24 new liquid-cooled structures were obtained based on the fractal concept by adding 6 geometrically structured branch channels to the traditional straight channel and adding different forms of secondary channels between the branch channels and between the branch channels and the main channel. On the basis of establishing a numerical simulation model and verifying the accuracy of the model, the thermal characteristics of 24 liquid-cooled structures were analysed by computational fluid dynamics (CFD) simulation, and the initial relative optimal liquid-cooled channel structure was obtained by taking the comprehensive thermal performance as the evaluation index. Then, the initial relative optimal channel structure parameters were optimised in steps using NSGA-II and grey correlation analysis algorithms. In order to further improve the heat transfer effect of the liquid-cooled plate, the relative optimal model after stepwise optimization was arced. The final results showed a decrease in the average temperature by 0.57 °C (1.6 %), an increase in the heat transfer coefficient by 356 W m−2 k−1 (21.3 %), and a decrease in the pressure drop by 34.55 Pa (50.2 %), as compared with the initial model. This study will provide some reference for the optimisation of the internal structural features of the channel and the improvement of the thermal performance of the liquid-cooled plate.