Numerical Study Of Combution With Triple Swirler

Combustion performance of model combustor with a triple-stage swirler has been investigated by numerical simulation method. The primary work of this study is to design several different triple-stage swirlers similarly in structure, taking the design method of single swirler as a reference. The central task of this study is to make numerical investigations on model combustor with different triple swirlers. The effects of various parameters of triple-stage swirler (such as vane angle, the number of swirler vanes, rotation direction of swirler vanes and airflow distribution among different stages of the swirler) on velocity distribution, temperature distribution and emissions of NO_x were studied numerically. By comparing the performance of triple-stage swirler model combustor and dual-stage swirler model combustor, influences of the swirler stages on combustor were also considered in this thesis.In the process of designing triple-stage swirler, dimension match and flow distribution among stages were taken into special consideration. Physical models chosen in the simulation include Realizable k-εturbulence model, non-premixed combustion model, DO (discrete ordinates) radiation model and thermal NO_x model etc. The computational method for simulating the flow field is SIMPLE (Semi-Implicit Method for Pressure Linked Equations). The numerical study indicates that parameters of triple-stage swirler and its rotation direction affect the velocity distribution, temperature distribution and emissions prosperities of model combustor to a varying extent, while the effect of swirler angle and rotation direction is more evident. Among several swirlers, the one with 3rd swirler angle 52°and counter-rotating stages has a better performance. The investigation results in this thesis will be a reference for optimum design of triple-stage swirler.