A nongray-wall Weighted-Sum-of-Gray-Gases method based on Full-Spectrum Correlated-K distribution for aero-engine combustors and afterburners

Thermal radiation greatly affects the performance of combustors and afterburners of aero-engines, thus, it is needed to predict the radiative heat transfer accurately and efficiently. In order to accommodate the nongray radiative property of the wall and the wide variation of pressure in combustors and afterburners, a nongray-wall WSGG with pressure varying continuously from sub-atmospheric to super-atmospheric conditions (ngWSGG-P) is proposed based on the Full-Spectrum Correlated-K distribution (FSCK), which can be employed to arbitrary wall materials and CO₂-H₂O mixtures with a temperature of 300 K–2800 K, a pressure of 0.4 atm–50 atm, and a mole fraction ratio of H₂O to CO₂ of 0.05–4.0. Two 1D flames with different pressures and length scales, and two 3D swirling and bluff-body flames with various pressures are simulated to evaluate the accuracy and efficiency of ngWSGG-P. The results show that ngWSGG-P demonstrates pretty good accuracy as compared to the benchmarks Line-By-Line and Narrow-Band Correlated-K methods, and its accuracy is close to 32-Points FSCK and better than other 3 typical WSGG methods. The computational time of ngWSGG-P is 13.7 % of that of FSCK, and close to other WSGG methods due to approximately the same number of gray gases.