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Mixing of multiple jets with a confined subsonic crossflow. Summary of NASA-supported experiments and modelingExperimental and computational results on the mixing of single, double, and opposed rows of jets with an isothermal or variable temperature mainstream in a confined subsonic crossflow are summarized. The studies were performed to investigate flow and geometric variations typical of the complex 3-D flowfield in the dilution zone of combustion chambers in gas turbine engines. The principal observations from the experiments were that the momentum-flux ratio was the most significant flow variable, and that temperature distributions were similar (independent of orifice diameter) when the orifice spacing and the square-root of the momentum-flux ratio were inversely proportional. The experiments and empirical model for the mixing of a single row of jets from round holes were extended to include several variations typical of gas turbine combustors. Combinations of flow and geometry that gave optimum mixing were identified from the experimental results. Based on results of calculations made with a 3-D numerical model, the empirical model was further extended to model the effects of curvature and convergence. The principle conclusions from this study were that the orifice spacing and momentum-flux relationships were the same as observed previously in a straight duct, but the jet structure was significantly different for jets injected from the inner wall wall of a turn than for those injected from the outer wall. Also, curvature in the axial direction caused a drift of the jet trajectories toward the inner wall, but the mixing in a turning and converging channel did not seem to be inhibited by the convergence, independent of whether the convergence was radial or circumferential. The calculated jet penetration and mixing in an annulus were similar to those in a rectangular duct when the orifice spacing was specified at the radius dividing the annulus into equal areas.
Document ID
19910014889
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Holdeman, James D. (NASA Lewis Research Center Cleveland, OH, United States)
Date Acquired
September 6, 2013
Publication Date
January 1, 1991
Subject Category
Aircraft Propulsion And Power
Report/Patent Number
E-6239
NASA-TM-104412
NAS 1.15:104412
AIAA PAPER 91-2458
Report Number: E-6239
Report Number: NASA-TM-104412
Report Number: NAS 1.15:104412
Report Number: AIAA PAPER 91-2458
Meeting Information
Meeting: Joint Propulsion Conference
Location: Sacramento, CA
Country: United States
Start Date: June 24, 1991
End Date: June 27, 1991
Sponsors: ASME, SAE, AIAA, American Socienty for Electrical Engineers
Accession Number
91N24202
Funding Number(s)
PROJECT: RTOP 537-02-21
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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