Rapid methods for calculating radiation transport in the entry environment

A procedure is developed for the prediction of radiation transport events in the context of the entry heating environment. The equivalent-width and exponential approximations are employed to reduce the computational requirements of the governing equations. Novel features are introduced in the use of an Elsasser band model to estimate line overlapping events and in the formulation of the wall reflection events. A matrix of calculations is presented to allow an assessment of the trade-offs between accuracy and computational efforts. It is concluded that the equivalent width model allows significant savings in computational effort with only modest penalties in accuracy. Consequently, the model should be viewed as an attractive candidate for use in radiation-coupled flow field prediction procedures