| The development of gas turbine technology has made demands on the combustionchamber due to higher load, smaller size and more server working conditions. Since gasturbine combustion chamber usually works in highly turbulent conditions, as one of itsenssential components, modifications of swirler structure often lead to variations of turbulentfluctuations in the downstream flow field, which affects the overall performance of thecombustion chamber. Therefore, it is of significant importance to investigate the influence ofturbulent fluctuation on combustion flow field. In this dissertation, the physical model of oneaero engine short annular combustion chamber is established. To investigate the influence ofstructure modifications on the combustion chamber’s performance when volume heat load isenhanced, numerical simulation of its combustion flow field is conducted for purpose ofbetter design.Firstly, CHEMKIN software is employed to determine the optimal air distribution ratioof the falme tube and then the micro-element method is employed to obtain the accurateeffective reaction area of each zone in the combustor to ensure that sufficient reaction volumncould be provided. Take1/20of the entire combustion chamber as the primary study subject athree-dimentional model of the combustion chamber is established according to sizerestrictions, which is equipped with a short diffuser and a two-stage swirl cup. Initialsimulation of the combustion flow field is conduected to see the characteristics of it. Thecombustion flow field is simulated to investigate the influence of various swirl cupsmodification on the combustion chamber’s performance. When carrying out numericalsimulation in Fluent software, Realizable k turbulence model and EDC combustion modelare employed; CONE injection model is used to simulate the atomization process of the fuel.To include the description of variation process of liquid oil droplets, the Particle trajectorymodel is activated. For equation discretions, the upwind scheme is utilized. Standard wallfunctionand the SIMPLE algorithm method are used to solve the wall problem and theequations, respectively.According to the calculated combustion parameters, changes of swirler structure caninfluence the turbulent kinetic energy and the turbulence intensity in the primary zone as well as the size of the recirculation zone, thus affecting the overall performance of the combustionchamber. The optimal structure combination swirl cup for optimal combustion performance is:the two stages of the swirl cup have the same swirl direction; first-stage swirler has8punctureholes of5mm in diameter and a60°angle while the second-stage swirler has10straight bladesof6.5mm in width and a70°installation angle. The outcome of this paper may providereference for future studies in the area of design and simulation of the combustion chamber. |
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