Heat transfer model for aerogel filled polyurethane composite

This work explores heat transfer mechanism in aerogel filled polyurethane composite. The heat transfer in the composite occurs through: conduction by solids, radiation on surface between neighbouring aerogel particles and natural thermal convection of gas in mesoporous aerogel particles. A theoretical model for heat transfer through conduction in aerogel filled polyurethane composites based on law of minimal thermal resistance and equal law of specific equivalent thermal conductivity was developed. The effective thermal conductivity of the composites was estimated using the derived equation and then compared with experimental data from the previous research. The results show that the predictions of effective thermal conductivity are close to measured data. One point to be considered is that, data taken from the past research are from polymer filled with high conductive fillers. Thus, when the derived equation is used to predict thermal conductivity of aerogel-filled polyurethane composite, the estimated value may differ with experimental value and may require a correction factor to count for all discrepancies.