2003 · 22 citations · 5 references
EngineeringMaterials EngineeringMaterials ScienceComputational Heat TransferHeat TransferRadiation TransportHeat ConductionHeat Transfer AnalysisHeat Transfer ModelingInsulation MaterialsRadiative Heat TransferThermal InsulationCombined Heat TransferConductive Heat TransferFibrous InsulationFibrous Insulation MaterialsNumerical Modeling Of InsulationPhase FunctionRadiative Transfer ModelingTransient Thermal Response
A first-principle approach is used to analyze combined conductive/radiative heat transfer in a high porosity silica insulation materials (LI900) currently used by the Space Shuttle. Using the measured value of the refractive index (n, κ), solutions to the radiative transfer equation for fibrous insulation with a random packing geometry is used to generate macroscopic average radiative properties such as extinction coefficient, scattering albedo and phase function. Based on a non-gray application of the zonal method, transient thermal response of the insulation tile subjected to an external radiant flux is generated and compared with experimental data. The agreement is excellent. The computation is both efficient and accurate. Numerical results show that even with the presence of conduction and large extinction coefficient in some wavelength region, a large temperature drop (“temperature slip”) occurs over a short distance near the heating surface. The inclusion of this effect is important for a correct interpretation of the heat transfer data.
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