A Coupled Model for Heat and Moisture Transport Simulation in Porous Materials Exposed to Thermal Radiation

Understanding mechanism of transmitted and stored heat in porous materials was extremely important for improving thermal protective performance of clothing. A coupled heat and moisture transfer model in a three-layer fabric system while exposing to a low-level thermal radiation was developed in this study. The model simulated the transmitted and stored heat in porous materials, and considered the effect of moisture transport on the transmitted and stored heat. The predicted results from the coupled model were validated with the experimental results, and compared with the predicted results from the previous model without considering the moisture effect. It was found that the prediction accuracies in skin burn and skin temperature through the coupled model were further improved. The coupled model was used to examine the moisture effect on heat transport and storage in porous materials. The results demonstrated that the moisture within porous materials increased the heat storage and discharge, but decreased the heat transport. The increases in initial moisture content and fiber moisture regain, while increasing the thermal hazardous effect, greatly enhanced the thermal protective performance of clothing. Therefore, it suggested that the moisture management in porous materials was a key consideration for thermal functional design of fabric.