An Efficient and Accurate Calculation Procedure for Atmospheric Radiation Transport

This Phase I SBIR project is aimed toward the development of a novel computational procedure that will allow accurate and fast prediction of radiative fluxes and transmission losses within the earth's atmosphere. The proposed calculation procedure is expected to be several orders of magnitude faster than the currently used very-narrow-band models in MODTRAN (or MODR), with accuracy comparable to that of line-by-line (LBL) calculations. The calculation procedure will be based on the recently developed (Michael Modest, Penn State University) full spectrum correlated-k distribution (FSCK) model, which allows accurate and superfast prediction of radiative fluxes in a medium comprising of participating molecular gases. This novel method is exact for homogeneous paths and its accuracy for inhomogeneous paths depends on the scaling technique (similar to the Curtis-Godson approximation) used for the absorption coefficient. The model has already been implemented in the commercial code CFD-ACE+ for combustion applications and validated extensively. In this project, we propose to demonstrate the feasibility of using this state-of-the-art model for atmospheric radiation calculations, pending required modifications and enhancements. To prove the feasibility, comparisons will be performed against LBL calculations to judge accuracy, and against MODTRAN and other narrow-band-model codes to judge speed.