Extended Injectant Mole-Fraction Imaging of Supersonic Mixing using Acetone PLIF

  • Takahashi, Hidemi (Department of Aerospace Engineering, Tohoku University) ;
  • Ikegami, Shuzo (Department of Aerospace Engineering, Tohoku University) ;
  • Hirota, Mitsutomo (Department of Mechanical Systems Engineering, Muroran Institute of Technology) ;
  • Masuya, Goro (Department of Aerospace Engineering, Tohoku University)
  • Published : 2008.03.30

Abstract

The fluorescence ratio method for processing planar laser induced fluorescence(PLIF) data was generalized for quantitative imaging of the injectant mole-fraction in supersonic mixing flowfields. The original fluorescence ratio approach was introduced by Hartfield et al. for tests in a special closed-loop wind tunnel to eliminate the effects of thermodynamic property variations in compressible flowfields and to provide a quantitative means of mole-fraction measurement. However, they implicitly assumed that the tracer molecules were seeded at the same fraction in both main and secondary flows. In the present study, we proposed generalizing the Hartfield method by considering differences in the tracer seeding rates. We examined the generalized method in a mixing flowfield formed by sonic transverse injection into a Mach 1.8 supersonic air stream. The injectant molefraction distribution obtained from PLIF data processed by our new approach showed better agreement with the gas chromatograph than one based on the Hartfield method.

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