Numerical Simulation And Experiment Of Combustion Flow In Plasma Ignition

Ignition reliability of gas turbine is an important factor under a cold start-up condition and it has something to do with maneuverability and security. If gas turbine cannot startup at first time, not only dose it cost more time to startup, but also may arouse a danger that gas turbine catch fire caused by the unburned fuel in combustion chamber. At same time, it may affect the security and the life-span of gas turbine.Plasma ignition for gas turbine engine is a new method which makes use of pyrolysis fuel energy to ignite the main fuel flux. The pyrolysis fuel energy is obtained in a combustion process lacking of oxygen in the plasma ignition device. There are advantages of the new ignition pattern, which has high ignition energy, broad ignition boundary and enhancing widely the ignition reliability and stability of gas turbine. Thus, it is important and significant to study plasma ignition technology and direct the structure design and application of plasma ignition device.In this dissertation, the plasma ignition technology and development of numerical simulation was introduced and the structure and character of chemical flow of plasma ignitor was analyzed in details. A suit of theory models to describe the turbulent flow and the chemical reaction and the numerical simulation were also brought forward. SIMPLEC algorithm method and body-fitted coordination grid were applied to simulate the parameters of turbulent combustion flows with two different fuels under different boundary conditions. With analyzing the results, the dissertation concluded reasonable conclusions and raised a new way, which is the total energy on the outlet to measure the ignition energy. Meantime, in order to value the ignition ability, an experiment to ignite the liquid and gas fuel with plasma ignitor was applied. From the results, this dissertation concluded the ignition boundary about the plasma ignitor. The work the dissertation deals with is important to direct design and application of the plasma ignitor.Based on the theory and experiment mentioned above, a new plasma ignitor design to prolong the life-span and reduce the weight with a forced-cooling electrode was presented. There are many advantages of the new project, such as a small volume, a simply structure, a good technics and a convenient maintenance. The numerical simulation mentioned above to simulate the combustion flow of new project under different air pressure and oil pressure conditions were adopted. With analyzing the results, an ignition performance about new project was showed with a curve. Furthermore, the feasibility was validated with an experiment.