Effects of core flow swirl on the flow characteristics of a scalloped forced mixer

Download
  1. Get@NRC: Effects of core flow swirl on the flow characteristics of a scalloped forced mixer (Opens in a new window)
DOIResolve DOI: http://doi.org/10.1115/1.4005968
AuthorSearch for: ; Search for: ; Search for: ; Search for:
TypeArticle
Journal titleJournal of Engineering for Gas Turbines and Power
ISSN0742-4795
Volume134
Issue11
Article number111201
SubjectCore flow; Equivalent diameter; Experimental investigations; Flow characteristic; Inlet swirls; Low swirl; Normal vortices; Pressure ratio; Radial velocity; Reversed flow; Streamwise vortices; Swirl angles; Temperature ratio; Thrust loss; Turbulence intensity; Vane geometry; Velocity ratio; Acoustic streaming; Deformation; Mixers (machinery); Mixing; Reynolds number; Vortex flow; Bypass ratio
AbstractThis paper presents a detailed experimental investigation of the influence of core flow swirl on the mixing and performance of a scaled turbofan mixer with 12 scalloped lobes. Measurements were made downstream of the mixer in a coaxial wind tunnel. The core-to-bypass velocity ratio was set to 2:1, temperature ratio to 1.0, and pressure ratio to 1.03, giving a Reynolds number of 5.2×10 5, based on the core flow velocity and equivalent diameter. In the core flow, the background turbulence intensity was raised to 5 and the swirl angle was varied from 0 deg to 30 deg with five vane geometries. At low swirl angles, additional streamwise vortices were generated by the deformation of normal vortices due to the scalloped lobes. With increased core swirl, greater than 10 deg, the additional streamwise vortices were generated mainly due to radial velocity deflection, rather than stretching and deformation of normal vortices. At high swirl angles, stronger streamwise vortices and rapid interaction between various vortices promoted downstream mixing. Mixing was enhanced with minimal pressure and thrust losses for the inlet swirl angles less than 10 deg. However, the reversed flow downstream of the center body was a dominant contributor to the loss of thrust at the maximum core flow swirl angle of 30 deg. © 2012 American Society of Mechanical Engineers.
Publication date
LanguageEnglish
AffiliationNational Research Council Canada (NRC-CNRC); Aerospace (AERO-AERO)
Peer reviewedYes
NPARC number21269296
Export citationExport as RIS
Report a correctionReport a correction
Record identifier064be747-e0cc-4a0f-afdd-64af83ddb768
Record created2013-12-12
Record modified2016-05-09
Bookmark and share
  • Share this page with Facebook (Opens in a new window)
  • Share this page with Twitter (Opens in a new window)
  • Share this page with Google+ (Opens in a new window)
  • Share this page with Delicious (Opens in a new window)