Transient combined radiation and conduction heat transfer in fibrous media with temperature and flux boundary conditions

Transient radiative and conductive heat transfer in a fibrous medium with anisotropic optical properties is investigated. Two different kinds of boundary conditions are treated: when the temperatures imposed on the boundaries vary with time and when the medium is subject to a radiation source which varies with time. A one dimensional case is considered. The non-linear transient Heat Conduction Equation is solved using the Kirchhoff transformation associated with a <f>P2</f> finite elements method using a non-uniform spatial mesh. The Radiative Transfer Equation is solved using a direct method which is analytical in space whereas the spectral scattering and absorption coefficients as well as the phase function are determined using the Mie theory. This procedure is applied on the whole time domain. Finally, a realistic application to a fibrous insulation composed of silica fibers is treated numerically. [Copyright &y& Elsevier]