A theoretical and numerical study on the gas-contributed thermal conductivity in aerogel

Abstract In this paper, a modified model for predicting the gaseous thermal conductivity in aerogel pores is proposed based on the kinetic theory of gases and the data from Direct Simulation Monte Carlo (DSMC) method. With the proposed modified model and the classical Effective Medium Theory (EMT) model, a gas-contributed thermal conductivity model which includes the equivalent gaseous thermal conductivity and the solid-gas coupling thermal conductivity is derived. The present gas-contributed model is validated by available experiment results for different types of aerogels. Comparisons between the present model and existing models show that the present gas-contributed model has a higher accuracy without complex calculations and assumptions.