NASA LogoNTRSNTRS - NASA Technical Reports ServerSearchmore_vertCollectionsAboutNewsHelpLogin Back to ResultsMixing 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 ID19910014889Acquisition SourceLegacy CDMSDocument TypeConference PaperAuthorsHoldeman, James D.*(NASA Lewis Research Center Cleveland, OH, United States)*Date AcquiredSeptember 6, 2013Publication DateJanuary 1, 1991Subject CategoryAircraft Propulsion And PowerReport/Patent NumberE-6239NASA-TM-104412NAS 1.15:104412AIAA PAPER 91-2458Meeting InformationMeeting: Joint Propulsion ConferenceLocation: Sacramento, CACountry: United StatesStart Date: June 24, 1991End Date: June 27, 1991Sponsors:ASME,SAE,AIAA,American Socienty for Electrical EngineersAccession Number91N24202Funding Number(s)PROJECT: RTOP 537-02-21Distribution LimitsPublicCopyrightWork of the US Gov. Public Use Permitted.Available DownloadsNameType19910014889.pdfSTIcloud_downloadcontent_copyvisibilityRelated RecordsThere are no records associated with this record.visibility_offNo Preview Available
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