Application of the extended weighted sum of gray gases model to light fuel oil spray combustion

Numerical and experimental studies have been conducted to examine the extended weighted sum of gray gases model (WSGGM), which takes account of nongray gases, suspended soot particles, and spray droplets in a multistage air/light fuel oil burner. The Eulerian balance equations for mass, momentum, energy, and species mass fractions were adopted with the standard k-ε turbulence model, whereas the Lagrangian approach was used for the particulate phase. The radiative transfer equation was solved using the discrete ordinates method with the two-phase WSGGM. In the NO chemistry model, the chemical reaction rates for thermal and prompt NO were statistically averaged using a probability density function. The results were validated by comparison with measurements. For the experiment, a 0.2 MW prototype multiannular burner was designed and fabricated. Comparisons between predicted and measured results were carried out to investigate the feasibility of application of the extended WSGGM to light fuel oil. The extended WSGGM gave reasonable agreements with the measurements except in the upstream region of combustor near the burner inlet.