Studies on counterflow diffusion flames

Counterflow;Diffusion Flames;Large-activation-energy Asymptotic Therory;Displacement Effects;Thermal Expansion;Slowly-varying Flames

Li, Lixiang

关键词: Counterflow;    Diffusion Flames;    Large-activation-energy Asymptotic Therory;    Displacement Effects;    Thermal Expansion;    Slowly-varying Flames;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/78555/LI-THESIS-2015.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

Certain aspects of counterflow diffusion flames are addressed in the context of one-step Arrhenius-type global chemical reaction. The general Large-activation-energy asymptotic theory for diffusion flames is first revised and then applied to one dimensional counterflow diffusion flames with finite separation distance between reactant supplies under constant density assumption. Comparisons are made between solutions for plug flow and for potential flow boundary conditions. Furthermore, the displacement effects of one dimensional counterflow diffusion flames in an infinite domain are studied by solving the governing boundary value problem numerically using Newton's method with a well defined analytical Jacobian. Based on the numerical results, a considerable increase in strain rate at the flame due to thermal expansion is observed, especially for fuel lean conditions. Finally, a potential flow that support a slowly varying two dimensional counterflow diffusion flame is proposed. The location of the curved flame front is determined by asymptotic techniques.