The main aim of this work is investigating the heat transfer properties of PAN nanofiber mats theoretically and experimentally. Nanofiber mats with different porosity and thickness were prepared by using a modified electrospinning system and the effect of porosity and thickness of nanofiber mats on heat transfer and air permeability of mats were invistigated. Darcy coefficient, in increase in the temperature of outer surface of nanofiber mats and thermal resistance were calculated. A heat transfer equation that incorporates the complex physical mechanisms of the conductive, radiative and convective heat transfer processes was used and developed an analytical and numerical solution scheme for the equation. The results were compared with experimental data. Furthermore, the effect of radiative heat transfer on overall heat transfer of nanofiber mats was considered. Results showed that nanofiber mats porosity is depended on rotational speed of drum. Also the results present that decreasing the bulk porosity and increasing the thickness of mats reduced the air permeability but enhanced Darcy coefficient of nanofiber mats. Also increasing bulk porosity and thickness decreased the temperature of nanofiber mats. Nanofibers mats have a good capability in reduction of heat transfer because of high porosity and this capability increases with increasing of porosity. Results obtained of numerical and analytical solutions of heat transfer equation were compatible. Comparing of experimental data with the results of analytical and numerical solution indicated that there is good agreement in the heat transfer trend properly in high porosity and low thickness of nanofiber mats. Prediction of heat transfer trend in low porosity and high thickness of nanofiber mats depends on the profile and size of pores that dont considered in the equation. Heat transfer analysis in nanofiber mats showed that radiative heat transfer compared to conductive and convective heat transfer has lower effect in overall heat transfer.
