Large-eddy simulation of a three-feed non-premixed flame for an oxy-fuel gas turbine burner

The development of turbulent combustion models for a three-feednon-premixed flame is essential for the research of gas-turbinein the oxy-fuel integrated coal gasification combined cycle (IGCC)system. The quasi-two-dimensional flamelet models are consideredeffective and accurate substitutes for the two-dimensional flameletmodel, however, there are still many aspects worth furtherinvestigations in terms of each dimension in the flamelet library.The considerations of heat loss, the presumed probability densityfunction (PDF), and the resolution of the diluent fraction in large-eddysimulation (LES) should be attached importance to. In thispaper, heat loss, diluent fraction PDF, and resolution of the diluentfraction have been investigated. It has been shown that the currentheat loss model in the flamelet equation can correctly interpret thereactions which are facilitated by high temperature. The beta-PDFused for diluent fraction results in a lower temperature in the flamezone than that of the delta-PDF as the diluent fraction fluctuationcannot be overlooked. And also, coarse resolution in terms of thediluent fraction gives interpolation error and should be paid attentionto.