A full-spectrum correlated-K distribution based weighted-sum-of-gray-gases method for gas-soot mixture in aero-engine combustors with nongray wall

Sooting flames are prevalent in aero-engine combustors, and their intense radiative emission can significantly affect combustor performance predictions. Accurate and efficient calculation of radiative heat transfer for such flames over a wide pressure range remain challenging. To address this, a new Weighted-Sum-of-Gray-Gases method (denoted as ngWSGG-PS) based on the Full-Spectrum Correlated-K distribution (FSCK) is developed. The method is designed for sooting flames bounded by nongray walls over a pressure range of 1–50 atm, and is applicable to temperatures of 300–2800 K, H₂O/CO₂ molar ratios of 0.05–4, and soot volume fractions of 0–20 ppm. The accuracy and efficiency of ngWSGG-PS are assessed using eight one- and three-dimensional flames with different length scales and soot concentration levels. 50 pressures are considered for each one-dimensional flame, and 9 pressures for each three-dimensional flame. Results show that ngWSGG-PS achieves accuracy comparable to the 32-node FSCK method and outperforms the other three typical WSGG methods. In most cases, the nongray wall treatment (ngWSGG-PS) yields higher accuracy than the gray wall assumption (denoted as gWSGG-PS). Moreover, the time required by ngWSGG‑PS to solve the radiative transfer equation is only 24.5%–37.7% of that needed by the 32‑node FSCK method and the other three WSGG methods based on the superposition approach.