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Fundamental Study of a Single Point Lean Direct Injector. Part I: Effect of Air Swirler Angle and Injector Tip Location on Spray CharacteristicsLean direct injection (LDI) is a combustion concept to reduce oxides of nitrogen (NOx) for next generation aircraft gas turbine engines. These newer engines have cycles that increase fuel efficiency through increased operating pressures, which increase combustor inlet temperatures. NOx formation rates increase with higher temperatures; the LDI strategy avoids high temperature by staying fuel lean and away from stoichiometric burning. Thus, LDI relies on rapid and uniform fuel/air mixing. To understand this mixing process, a series of fundamental experiments are underway in the Combustion and Dynamics Facility at NASA Glenn Research Center. This first set of experiments examines cold flow (non-combusting) mixing using air and water. Using laser diagnostics, the effects of air swirler angle and injector tip location on the spray distribution, recirculation zone, and droplet size distribution are examined. Of the three swirler angles examined, 60 deg is determined to have the most even spray distribution. The injector tip location primarily shifts the flow without changing the structure, unless the flow includes a recirculation zone. When a recirculation zone is present, minimum axial velocity decreases as the injector tip moves downstream towards the venturi exit; also the droplets become more uniform in size and angular distribution.
Document ID
Document Type
Conference Paper
Tedder, Sarah A.
(NASA Glenn Research Center Cleveland, OH, United States)
Hicks, Yolanda R.
(NASA Glenn Research Center Cleveland, OH, United States)
Tacina, Kathleen M.
(NASA Glenn Research Center Cleveland, OH, United States)
Anderson, Robert C.
(NASA Glenn Research Center Cleveland, OH, United States)
Date Acquired
April 27, 2015
Publication Date
July 28, 2014
Subject Category
Aircraft Propulsion And Power
Fluid Mechanics And Thermodynamics
Report/Patent Number
Meeting Information
AIAA/ASME/SAE/ASEE Joint Propulsion Conference(Cleveland, OH)
Funding Number(s)
WBS: WBS 794072.
Distribution Limits
Work of the US Gov. Public Use Permitted.
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