Multigroup Correlated-k Distribution Method for Nonequilibrium Atomic Radiation

Accurate and efficient modeling of shock-layer radiative heat loads is critical for many spacecraft designs. A correlated-k distribution method has been developed for the most important atomic species (N and O), which provides great accuracy with high numerical efficiency for the evaluation of radiative transfer in a hot plasma. Challenges posed by typical nonequilibrium gas conditions and extreme concentration and temperature gradients in the shock layer were overcome by splitting the full spectrum into a number of nonoverlapping part spectra. Results for one-dimensional nonhomogeneous gas slabs are presented, comparing line-by-line benchmarks with the fullspectrum correlated-k model, showing very good accuracy with a maximum error of 2–3% for the stagnation-line flowfield of the Stardust vehicle and more severe nonhomogeneous two-cell problems.