A topology optimization-based design method for liquid cooling garments (LCGs) is proposed, aiming to enhance the heat flow performance of LCG systems by optimizing the internal microchannel structures. The primary objective is to improve flow and heat transfer characteristics in high-temperature environments, ensuring efficient heat dissipation. To achieve this, a novel liquid cooling film replaces traditional fixed hose structures and integrates with a water-cooled heat exchanger, forming a modular system that facilitates rapid assembly. A variable-density topology optimization model is applied to refine the microchannel configurations, examining the effects of fluid domain volume fractions and multi-objective weighting factors. The findings indicate that as the volume fractions increase, the microchannel designs become finer, leading to improved heat dissipation efficiency and reduced pressure drop. Numerical simulations and experimental validations reveal that the topology-optimized (TO) model outperforms traditional designs (TRA and TRB) in terms of heat flow performance, as observed in studies on flow fields, pressure distributions, temperature profiles, and Nusselt numbers. Specifically, the TO model reduces the average temperature by 30.96% compared to TRA and the maximum temperature by 19.46% compared to TRB at a flow rate of 240 ml/min. At a voltage of 8 V and a flow rate of 700 ml/min, the TO-designed LCGs achieve a steady-state temperature of 24 °C, exhibiting superior performance under high-flow scenarios. The TO design also demonstrates faster thermal equilibrium and a reduced temperature gradient, contributing to enhanced wearer comfort. This research confirms the efficacy of topology optimization, offering a theoretical basis and practical framework for developing high-performance LCG systems.
