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Heat exchangers are general equipment for energy exchange in the industrial field. Enhancing the heat transfer of a heat exchanger with low pump energy consumption is beneficial to the maximum utilization of energy. The optimization design for enhanced heat transfer structure is an effective method to improve the heat transfer coefficient. Present research shows that the biomimetic structures applied in different equipment could enhance heat transfer and reduce flow resistance significantly. Firstly, six biomimetic structures including the fractal-tree-like structure, conical column structure, hybrid wetting structure, scale structure, concave-convex structure and superhydrophobic micro-nano structure were summarized in this paper. The biomimetic structure characteristics and heat transfer enhancement and drag reduction mechanisms were analyzed. Secondly, four processing methods including photolithography, nanoimprinting, femtosecond laser processing and 3D printing were introduced as the reference of biomimetic structure machining. Finally, according to the systemic summary of the research review, the prospect of biomimetic heat transfer structure optimization was proposed.

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To improve the thermal performance of electric vehicle batteries, a novel cooling system of liquid cold plates coupled with air flow channels (LCP-AFC) for battery thermal management was proposed. Three-dimensional models were established for simulation. The effects of five factors on the heat dissipation of the electric vehicle battery module were studied, which included the battery discharge rate, inlet temperature of cooling liquid, nanofluids, airflow velocity, liquid, and air flow directions. The results showed that the maximum temperature T max and temperature difference ΔT of the battery module under 1 C discharge rate could be reduced by 1.1°C and 0.92°C compared to the single liquid cooling. Comparing the LCP-AFC with single air cooling, the T max and ΔT of the battery module under 4 C discharge rate could be reduced by 18.74°C and 2.71°C. The temperature uniformity of the battery module was not satisfied with the inlet temperature of the cooling liquid, which was lower than 15°C. The heat transfer performance was improved by adding Al, Cu, or Ag nanoparticles into the deionized water. Among them, Ag-water nanofluid had the most significant cooling effect. Parallel flow indicated better thermal performance than cross flow and counter flow. The developed cooling system of LCP-AFC offers a new method to design lithiumion battery thermal management system for controlling temperature distribution of a battery module.