Inverse radiation problem in three-dimensional complicated geometric systems with opaque boundaries

An inverse radiation analysis is presented to identify the three-dimensional source term distribution in complicated geometric systems of known radiative properties from the knowledge of the exit radiative intensities. The inverse radiation problem is formulated as an optimization problem, and solved by the conjugate gradient method that minimizes the errors between the calculated exit radiative intensities and the experimental data. The measured data are simulated by adding random errors to the exact solution of the direct problem. The analysis consists of the direct problem, the gradient equation, and the sensitivity problem. In this approach, the discrete ordinates method is employed to solve the direct and the sensitivity problems in general body-fitted coordinates. The effects of the measurement errors, single scattering albedo, and scattering asymmetry parameter on the accuracy of the inverse analysis are investigated. The study shows that the three-dimensional source term distribution in complicated geometric systems with opaque and diffuse-gray boundaries can be estimated accurately for the exact and noisy data. (C) 2001 Elsevier Science Ltd. All rights reserved.