CORRELATION OF MEASURED AND COMPUTED RADIATION INTENSITY EXITING A PACKED-BED

The spectral and directional distribution of radiation intensity is me asured using a direct radiometric technique, at the exposed boundary o f a packed bed of stainless steel spheres. The purpose of these measur ements is to provide an experimental data base of radiation intensify with which to correlate intensity field solutions of the radiative tra nsfer equation in participating media. The bed is considered to be one -dimensional, is optically thick, and has measured constant-temperatur e boundary conditions. Intensity exiting the bed is numerically simula ted using a discrete ordinates solution to the radiative transfer equa tion, with combined mode radiation-conduction solution of the coupled energy conservation equation. Radiative properties for the bed are com puted using the large size parameter correlated scattering theory deri ved by Kamiuto from the general theory of dependent scattering by Tien and others. The measured intensity results show good agreement with c ompared results in near-normal directions, though agreement in near-gr azing directions is poor. This suggests that either radiative transfer near the boundaries of this medium might nor be adequately represente d by a continuous form of the radiative transfer equation, or that the properties derived from correlated scattering theory are insufficient . In either case, development of a more detailed radiation model for s pherical packed beds appears warranted.