THERMAL CONDUCTIVITY OF FIBER-FILLED AEROGELS

A theoretical model is presented for computing the thermal conductivity of fiber-filled aerogels in terms of fiber and aerogel radiative properties, fiber and aerogels bulk densities, temperature and ambient gas pressure. Numerical results are compared with experimental radiative properties and heat wander data to demonstrate the validity of the model. Experimental data are for silica and silicon carbide fibers at several volume fractions in silica aerogel. Heat transfer data were measured in air at ambient pressure over a temperature range from 400 to 1,200 K. Excellent agreement between theory and experiment is seen in all cases.