| Summary: | 碩士 === 逢甲大學 === 機械工程學所 === 93 === In this study, a three dimensional numerical simulation was performed to analyze the phenomena of coaxial jets burning field by changing dump ratio and the tangential velocity. The simulation adopts κ-εturbulence model and eddy-dissipation combustion model which is one-step reaction process. The control-volume integration model was used to set up the difference equation. The SIMPLE algorithm was employed in the numerical scheme.
The investigation of this study was divided into two parts. The first part consider the change of the burner dump ratio which has three different values 2,4,and 6. The second part consider the change of the two inlet swirling angles which also have three different values 30°、45°and 60°. The inlet swirling angle can increasing the tangential velocity and the mixing flow field. The air inlet （outer jet）and fuel（inner jet）having same swirling angle, different angle ,and no angle were considered to the effects of the mixing flow field in the burner.
The focuses of the burner design are combustion efficiency , thrust, and performance safety. Through the simulation results of this study ,we obtained the temperature, velocity and the turbulence kinetic distribution field inside the burners , Also ,we obtained the surface temperature distribution and the fuel concentration . These parameters provide the designer how to chose the best burner dump ration to obtain the better combustion efficiency and the avoid to the energy wasted.
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