CFD Simulation of Thermal–Moisture Comfort of Clothing Fabrics in Hot–Dry Climate

To investigate the effect of clothing fabrics on human thermal and moisture comfort in dry–hot environments, computational fluid dynamics (CFD) was employed to analyze the thermal–moisture coupling mechanisms within the human–clothing–environment system. Nine commercially available fabrics of different materials were selected, and their performance parameters were tested. Four fabrics with similar specifications were then selected, and a clothing simulation was conducted under constant dry–hot environmental conditions of 35°C and 30% relative humidity (RH). By monitoring the dynamic changes in the under-garment microclimate (temperature and relative humidity) in sweat-prone areas of the human torso, including the front chest, back, and abdomen, we investigated the effect of different fabric materials on human thermal and hygroscopic comfort in a dry–hot environment. The results indicate that F4, containing Lyocell, demonstrated the best under-garment temperature and humidity regulation performance across the three key areas. Its steady-state temperatures in the abdomen and front chest were approximately 0.5–0.6% lower than those of F5, and the amplitude of fluctuations was significantly smaller than that of other fabrics. The under-garment relative humidity of F4 was generally maintained within the range of 55–70% RH, which is approximately 15–30% lower than that of F2, enabling more effective maintenance of a relatively stable microenvironment. This indicates that in dry and hot summer environments (such as the Xinjiang region), Lyocell fabric can have a positive effect on human thermal and humidity comfort. This study provides a theoretical basis and data reference for the selection and design of functional clothing materials in such environments.