Numerical Simulation Of Turbulence Diffusion Combustion In Plasma Ignition

The plasma ignition is one of the new ignition devices that produced when the plasma technology is applied in the power and energy project domain. As early as the end of 1980s the ignition process has been applied to the gas turbine in aviation and on road. At the same time the plasma ignition technology has been started application in the less oil ignition of the coal fuel in the power plant ,the steady combustion process and the fuel ignition in each kind of hot equipment and burning craft.High density energy of the plasma ignition carries on the heat and chemical effect to the air and the fuel mixture, produces a great deal of plasma activation carrier, broadens the ignition limit scope of the rich fuel and poor fuel in the firebox and enhances the reliability of the ignition. At the same time, it accelerates the rate of chemical reaction, enhances the efficiency of the combustion, saves the fuel and strengthens the stability of the burning in the firebox.The air and fog fuel in the igniter experiences an extremely complex process, which involves the turbulence flow, heat transfer, mass transfer, chemical reaction, radiation and so on. For the non-linear controls simultaneous differential equation that describes the process, we can not solve it with the analysis law yet. As for the burning equipment, if we can not profoundly understand and accurately describe its work process, it will be quite difficult to construct effective equipment.This dissertation carries on the three dimensional simulation to the combustion process in the plasma ignition. For the actual geometry model, it establishes a mathematics physical model of the non-premixed turbulence diffusion combustion and presents the governing simultaneous differential equation.(1) To the turbulence model, it selects the standardκ-εturbulence model and RNGκ-εturbulence model for simulative calculation separately, and then analyzes and compares the results of the velocity field, the turbulence kinetic energy and the turbulent dissipation rate. The above process concludes that the RNGκ-εturbulence model has considered the effect of the strive streamline bend,spire and eddy, so it will be more suitable to the plasma ignition.(2) To the process of the radiation heat transfer, it uses the DTRM model and the DO model to simulate computation, and compares the temperature field, absorption coefficient and radiation temperature. It is thought that better results can be received by using the DO model because it considers the effect of the soot and the dispersion and describes the actual process wonderfully.(3) It uses the turbulence combustion theory to analyze and describe the turbulence combustion process in the plasma ignition and then adopts the simple chemical reaction system under the partial chemistry balance supposition, which selects 15 kinds of fuel, air and intermediary products altogether. Thus it describes the systematic burning chemical reaction mechanism by the computation results by simulation the mean mixture fraction and the mass fraction of the composition combined with the basic law of the combustion theory.(4) It adopts the LES model and the sub-grid scale model to analyze the results of the temperature, velocity field.(5) To the calculation region in the plasma ignition we introduce the body coordinates system, uses the unstructured grid to disperse and the discrete governing equations of the finite volume method, applies the SIMPLE method in the staggered unstructured grid. For the different instance we use the different discrete governing equation and difference discrete scheme. The chosen scheme includes the first order upwind scheme, the second order upwind scheme and the QUICK scheme.