Swirling flows in an annular-to-rectangular transition section

Sobota, Thomas H.; Marble, Frank E.

doi:10.2514/3.23157

Cited by 7 publications

(1 citation statement)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2 Enhancement of fuel-air mixing in aircraft engines for these purposes has been traditionally accomplished essentially through streamwise vorticity generation 5 via transverse jet injection 6 or via axial swirl introduction. 7 It has been suggested, however, that there may exist optimal levels of fuelair premixing ͑or fuel dilution with air͒, beyond which mixing enhancement could increase NO x emissions due to reduced sooting and associated radiative heat losses. 8,9 The lobed fuel injector is designed to passively control fuel-air mixing via streamwise vorticity generation.…”

Section: Introductionmentioning

confidence: 99%

Numerical simulations of a lobed fuel injector

1998

View full text Add to dashboard Cite

Numerical modeling of the nonreactive mixing processes associated with a lobed fuel injector in a coflowing air stream is presented. The lobed fuel injector is a device which generates strong streamwise vorticity, producing locally high strain rates which can enhance the molecular mixing of reactants while delaying ignition in a controlled manner. Vortex element modeling is used to simulate flow field evolution and fuel element mixing characteristics for this lobed fuel injector. Quantitative predictions for vorticity generation and qualitative results for streamwise rollup compare well qualitatively with recent experimental investigations of this flow field ͓Smith et al., Phys. Fluids 9, 667 ͑1997͔͒. Parametric studies of the effects of lobe amplitude-to-wavelength ratio, lobe angle, and lobe shape for given flow conditions suggest that geometrical features may be optimized to enhance mixing and control reaction processes.

show abstract

Section: Introductionmentioning

confidence: 99%

Numerical simulations of a lobed fuel injector

1998

View full text Add to dashboard Cite

show abstract

Swirling flows in circular-to-rectangular transition ducts

Miau

Lin

Chen

et al. 1996

Experiments in Fluids

View full text Add to dashboard Cite

Swirling flows in three circular-to-rectangular transition ducts, each of them with an aspect ratio of 2.0 at the rectangular exit, have been studied experimentally. The swirling flows were produced by swirlers whose vane angles were at 5 ~ 10 ~ and 20 ~ inclinded to the incoming flow, respectively. Flow visualization experiments were made at selected cross-sectional planes in the transition ducts. Pressure and velocity measurements were obtained on the contoured duct walls and at the rectangular exit planes, respectively. The results show that the swirling flow pattern evolves into a skewed structure at the exit plane which, in connection with the wall pressure distributions, is asymmetric with respect to the centerline of either the top and bottom walls or the side walls. Moreover, an analysis based on the mean streamwise vorticity equation with the velocity data obtained immediately downstream of the rectangular exit plane indicates that the cross-stream Reynolds stress plays an important role in transporting the streamwise vorticity of the swirling flow into the surrounding fluid.

show abstract