Heat Transfer Modeling for Rigid High-Temperature Fibrous Insulation

Abstract

Combined radiation and conduction heat transfer through a high-temperature, highporosity, rigid multiple-fiber fibrous insulation was modeled using a thermal model previously used to model heat transfer in flexible single-fiber fibrous insulation. The rigid insulation studied was alumina enhanced thermal barrier (AETB) at densities between 130 and 260 kg/m 3 . The model consists of using the diffusion approximation for radiation heat transfer, a semi-empirical solid conduction model, and a standard gas conduction model.

Micro-tomography based analysis of thermal conductivity, diffusivity and oxidation behavior of rigid and flexible fibrous insulators

“…Radiative transfer within the porous medium was not modeled. While existing literature has highlighted the importance of radiative conductivity for FiberForm and similar insulators operating at high temperature [17][18][19][20][21], this is an acceptable approximation for the present work, as only values at room temperature were considered.…”

Study of geometrical characteristics effects on radiation properties in high porosity fibrous porous media using the pore-scale simulation and two-flux model

“…In order to use experimental results presented by Daryabeigi [6,12,25], the medium density was considered to be 48 kg/m 3 and nitrogen gas with the pressure of 0.67 kPa was considered as the fluid occupying the porous medium. The thermal conductivity of the nitrogen gas increases with temperature, and in contrast, it has a decreasing trend in alumina.…”

“…The radiation properties of the porous media are the combination of the solid and fluid parts which can be obtained by different methods [5][6][7][8]. Since direct measurement of these properties is difficult, inverse method is commonly used as an alternative approach in which data obtained from experiments are used as inputs for the solutions of the governing equations [9].…”

Meta-model based stochastic simulation of fire barrier cold-side temperature

“…For a porous structure such as gypsum and stone-wools, however, the heat transfer occurs in all three modes: conduction, convection and radiation, and the structure contains reactive material that decomposes at high temperature and triggers mass transfer within the structure [27,28]. Furthermore, the availability of oxygen within the porous region affects the rate of the chemical reactions and the overall heating behaviour of the structure [1,29].…”