Experimental And Numerical Study On Oil Flame Stracture Of A Dual-swirler

To meet the modern aero-engine operating characteristics in variable condition, dual-swirl burner emerged. However, there is less research on visualization in dual-swirler flame structure. This paper focuses on the flame structure and combustion characteristics of dual-swirler oil burner with the mean of conducted research and numerical simulation. The main focus is to explore the influence of equivalence ratio, the inner swirler vane angle and the rotation of the two swirler on the flame structure and combustion characteristics, and trying to analyze the reasons for these effects from the flow structure. Experiments using a planar laser-induced fluorescence(OH-PLIF) technique for the diagnosis of flame structure and use thermocouples and gas analyzers for combustion characteristics measuring. For the purpose of analyzing flame structure quantitatively, this paper defines the flame trajectory curve, the flame deflection angle, the flame start angle and the area of flame. In the numerical part, using Fluent to simulate the combustion process in the experiment conditions, and comparing the experimental results with the simulation results to mutatis mutandis the accuracy of numerical simulation results. Finally, using the data obtained in the numerical calculation of the flow structure to analyze the position and shape of the dual-fuel flame. Study found that:The influence of the equivalence ratio and the variable of the dualswirler geometry structure which can continuous change on flame characters has a characteristic value, the value of these characteristics will be divided into different sections, in each interval, there will be one variable affects the combustion characters determinatively;The relative rotation of the inside and outside swirler has little impact on the temperature distribution of the combustor outlet, but same one has a low NO emission comparing with the opposite one. The vane angle of the inner swirler is bigger, the NO emissions is lower, but it doesn’t has a regular effect on the distribution of the combustor exit.Dual-swirler oil flame stabilizes in an area of flow field with specific fluid velocity, the equivalent ratio will affect the characteristics of the region, at a high equivalent ratio, the region locate where radial velocity is minimum, and at a low equivalence ratio, the region in the tangential velocity is at a minimum.