Abstract
In this paper, an industrial gas-turbine combustor was numerically investigated by applying large-eddy simulation for turbulent model and 2-scalar flamelet approach for combustion model. In the combustion model, the structures of premixed and non-premixed flame are expressed by conservative scalar and levelset function respectively. These two concepts are coupled for partial premixed combustion field. Flow field properties inside the flame (temperature, density, laminar flame speed) are determined by "flamelet data". The flamelet data is mainly divided in "premixed-like flamelet data" and "diffusion-like flamelet data" in this study. The premixed-like flamelet data is based on chemical equilibrium assumption and is evaluated by 0-dimensional chemical reaction calculation. On the other hand, the diffusion-like flamelet data is based on laminar flamelet assumption and is evaluated by 1-dimensional counter flow combustion calculation. In this study, for the diffusion-like combustion field in the industrial combustor, diffusion-like flamelet data was newly applied. The predicted gas temperature showed a little higher value than the temperature calculated by using the premixed-like flamelet data. However, the predicted temperatures underestimated measured one. Therefore, in this case, it was cleared that difference of flamelet data is insignificant for improving analysis accuracy.
