Application of jet shear layer mixing and effervescent atomization to the development of a low nitrogen oxide combustor
Abstract
An investigation has been conducted to develop appropriate technologies for a low NO$\sb{\rm x}$, liquid-fueled combustor. The combustor incorporates an effervescent atomizer used to inject fuel into a premixing duct. Only a fraction of the combustion air is used in the premixing process to avoid autoignition and flashback problems. This fuel-rich mixture is introduced into the remaining combustion air by a rapid jet shear layer mixing process involving radial fuel-air jets impinging on axial air jets in the primary combustion zone. Computational analysis was used to provide a better understanding of the fluid dynamics that occur in jet shear layer mixing and to facilitate a parametric analysis appropriate to the design of an optimum low NO$\sb{\rm x}$ combustor. A number of combustor configurations were studied to assess the key combustor technologies and to validate the modeling code. The results from the experimental testing and computational analysis indicate a low NO$\sb{\rm x}$ potential for the Jet Shear Layer combustor. Key features found to affect NO$\sb{\rm x}$ emissions are the primary combustion zone fuel-air ratio, the number of axial and radial jets, the aspect ratio and radial location of the axial air jets, and the radial jet inlet hole diameter. Each of these key parameters exhibits a low NO$\sb{\rm x}$ point from which an optimized combustor was developed. Using this approach, NO$\sb{\rm x}$ emissions were reduced by a factor of three as compared to conventional, liquid-fueled combustors operating at cruise conditions. Further development promises even lower NO$\sb{\rm x}$ with high combustion efficiency.
Degree
Ph.D.
Advisors
Lefebvre, Purdue University.
Subject Area
Mechanical engineering|Aerospace materials
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