Comparative performance of nongray gas modeling techniques

This study compares the relative efficiencies (accuracy and computation time) of five methods developed for characterizing radiative exchanges in enclosures, mono- and bi-dimensional, containing real gases: the correlated-k method (CK), three versions of the hybrid CK/statistical narrow-band method (SNB-CK), and the spectral line-based weighted sum of gray gases method (SLW). Attention is drawn to the hybrid SNB-CK method featuring band regrouping strategies. The version proposed in this article, which is characterized by a selective regrouping of bands, leads to good results, while the computation time is significantly decreased with respect to the original SNB-CK version. Mono- and bi-dimensional enclosures are analyzed. Diagrams illustrate the reeommended fields of application of the various methods.