Inverse Estimation of Thermal Properties in a Semitransparent Graded Index Medium With Radiation-Conduction Heat Transfer

An inverse radiation-conduction analysis is performed for simultaneous estimation of the thermal properties in an absorbing, emitting, and linear-anisotropically scattering medium with spatially variable refractive index. The discrete ordinates method in conjugation with finite volume method is adopted to solve the direct problem. The conjugate gradient method (CGM) is employed to simultaneously estimate the conduction-radiation parameter, optical thickness, single scattering albedo, scattering phase function, and the wall emissivities from the knowledge of the exit radiation intensities over the boundaries. The effects of these parameters and the measurement errors on the precision of the inverse analysis are investigated. Results show that the proposed inverse approach can successfully retrieve the unknown parameters for different refractive index profiles.