Updated Weighted-Sum-of-Gray-Gases Model Parameters for a Wide Range of Water and Carbon Dioxide Concentrations and Temperatures up to 5000 K

Journal article, 2025

The weighted-sum-of-gray-gases model (WSGGM) is a commonly used radiative properties model for combustion engineering applications. This work presents updated WSGGM parameters from our previously published WSGGM to cover a temperature range up to 5000 K for pure H2O and CO2 species as well as mixtures of the two. The gases are considered ideal at all temperatures and new conditions are covered in comparison to existing WSGGM parameters; examples of engineering applications are hydrogen combustion, oxygen-enriched, and oxy-fuel combustion as well as thermal and hybrid plasma systems applying either H2O- or CO2-based plasma conditions. Thus, the parameters are considered relevant in high-temperature processes where gas dissociation effects are unknown. The updated sets of WSGGM parameters are compared to existing WSGGMs by predicting the total emissivity for different gaseous domains; the computational accuracy is assessed using the statistical narrow band model (SNBM) as a reference. Additional comparisons applying the WSGGMs for predicting the radiative source term under nonisothermal and nonhomogeneous conditions in a gaseous domain consisting of two infinite black plates are also included. The results show the suitability of the updated model parameters for such conditions and the increasing deviation error from the SNBM for existing WSGGMs when used outside of their temperature limits. The updated parameters achieve a mean deviation error from the SNBM of below 20% for most cases, which is at a range similar to previous works.