Heat transfer simulation and parametric design for firefighter protective clothing under high heat exposure

The purpose of this study was to investigate the heat transfer of fire-resistant fabric and to propose an objective-driven optimization approach for parametric design. A finite volume method (FVM) model was developed to predict the thermal response within the fabric-air gap-skin system under flash fire exposure. Parametric correlations were conducted to identify crucial variables, and optimization designs were performed using surrogate models combined with non-dominated sorting genetic algorithm II (NSGA-II) based on numerical simulations. The results demonstrated that the numerical model accurately predicted the skin temperature with a relative error of 5.0% for single-layer fabrics and 1.8% for muti-layer combinations. Fabric thickness was the dominant parameter affecting skin burns, followed by air gap width and thermophysical properties. Emissivity and transmissivity were not significantly correlated with second-degree burn time. Multi-objective optimization revealed an optimal configuration for single-layer fabric: a 22.0% increase in thickness and a 20.0% increase in porosity, which extended second-degree burn time by 32.1% without compromising weight efficiency. Additionally, textiles with a thickness of 1.38 mm (MB) and a volumetric heat capacity of 1.16×10 ⁶ J/(m ³ K) (TL) exhibited considerable potential for high thermal protection and lightweight design. Research findings in this study will provide a novel approach for intelligent optimization of firefighter protective clothing, and the proposed methodology can also be extended to the development and multifunctional applications of industrial textiles.