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Transverse jet mixing characteristics

Published online by Cambridge University Press:  02 February 2016

L. Gevorkyan ,
T. Shoji ,
D. R. Getsinger ,
O. I. Smith  and
A. R. Karagozian
L. Gevorkyan
Affiliation:
Department of Mechanical and Aerospace Engineering, University of California, Los Angeles, CA 90095-1597, USA
T. Shoji
Affiliation:
Department of Mechanical and Aerospace Engineering, University of California, Los Angeles, CA 90095-1597, USA
D. R. Getsinger
Affiliation:
Department of Mechanical and Aerospace Engineering, University of California, Los Angeles, CA 90095-1597, USA
O. I. Smith
Affiliation:
Department of Mechanical and Aerospace Engineering, University of California, Los Angeles, CA 90095-1597, USA
A. R. Karagozian*
Affiliation:
Department of Mechanical and Aerospace Engineering, University of California, Los Angeles, CA 90095-1597, USA
*
†Email address for correspondence: ark@seas.ucla.edu
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Abstract

This experimental study explores and quantifies mixing characteristics associated with a gaseous round jet injected perpendicularly into cross-flow for a range of flow and injection conditions. The study utilizes acetone planar laser-induced fluorescence imaging to determine mixing metrics in both centreplane and cross-sectional planes of the jet, for a range of jet-to-cross-flow momentum flux ratios ($2\leqslant J\leqslant 41$), density ratios ($0.35\leqslant S\leqslant 1.0$) and injector configurations (flush nozzle, flush pipe and elevated nozzle), all at a fixed jet Reynolds number of 1900. For the majority of conditions explored, there is a direct correspondence between the nature of the jet’s upstream shear layer instabilities and structure, as documented in detail in Getsinger et al. (J. Fluid Mech., vol. 760, 2014, pp. 342–367), and the jet’s mixing characteristics, consistent with diffusion-dominated processes, but with a few notable exceptions. When quantified as a function of distance along the jet trajectory, mixing metrics for jets in cross-flow with an absolutely unstable upstream shear layer and relatively symmetric counter-rotating vortex pair cross-sectional structure tend to show better local molecular mixing than for jets with convectively unstable upstream shear layers and generally asymmetric cross-sectional structures. Yet the spatial evolution of mixing with downstream distance can be greater for a few specific convectively unstable conditions, apparently associated with the initiation and nature of shear layer rollup as a trigger for improved mixing. A notable exception to these trends concerns conditions where the equidensity jet in cross-flow has an upstream shear layer that is already absolutely unstable, and the jet density is then reduced in comparison with that of the cross-flow. Here, density ratios below unity tend to mix less well than for equidensity conditions, demonstrated to result from differences in the nature of higher-density cross-flow entrainment into lower-density shear layer vortices.

JFM classification

Instability: Absolute/convective instability Wakes/Jets: Jets Mixing: Mixing
Type
Papers
Information
Journal of Fluid Mechanics , Volume 790 , 10 March 2016 , pp. 237 - 274
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Copyright
© 2016 Cambridge University Press 

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References

Bagheri, S., Schlatter, P., Schmid, P. J. & Henningson, D. S. 2009 Global stability of a jet in crossflow. J. Fluid Mech. 624, 33–44.Google Scholar
Boss, J. 1986 Evaluation of the homogeneity degree of a mixture. Bulk Solids Handling 6 (6), 1207–1215.Google Scholar
Broadwell, J. E. & Breidenthal, R. E. 1984 Structure and mixing of a transverse jet in incompressible flow. J. Fluid Mech. 148, 405–412.Google Scholar
Brown, G. L. & Roshko, A. 1974 On density effects and large structure in turbulent mixing layers. J. Fluid Mech. 64, 775–816.CrossRefGoogle Scholar
Cortelezzi, L. & Karagozian, A. R. 2001 On the formation of the counter-rotating vortex pair in transverse jets. J. Fluid Mech. 446, 347–373.Google Scholar
Danckwerts, P. V. 1952 The definition and measurement of some characteristics of mixtures. Appl. Sci. Res. A 3, 279–296.Google Scholar
Davitian, J., Getsinger, D., Hendrickson, C. & Karagozian, A. R. 2010a Transition to global instability in transverse-jet shear layers. J. Fluid Mech. 661, 294–315.Google Scholar
Davitian, J., Hendrickson, C., Getsinger, D., M’Closkey, R. T. & Karagozian, A. R. 2010b Strategic control of transverse jet shear layer instabilities. AIAA J. 48 (9), 2145–2156.Google Scholar
Dimotakis, P. E. & Miller, P. L. 1990 Some consequences of the boundedness of scalar fluctuations. Phys. Fluids A 2 (11), 1919–1920.Google Scholar
Fearn, R. & Weston, R. 1974 Vorticity associated with a jet in a crossflow. AIAA J. 12, 1666–1671.Google Scholar
Forliti, D. J., Salazar, D. V. & Bishop, A. J. 2015 Physics-based scaling laws for confined and unconfined transverse jets. Exp. Fluids 56, 36.Google Scholar
Fric, T. F. & Roshko, A. 1994 Vortical structure in the wake of a transverse jet. J. Fluid Mech. 279, 1–47.CrossRefGoogle Scholar
Getsinger, D. R.2012 Shear layer instabilities and mixing in variable density transverse jet flows. PhD thesis, UCLA.Google Scholar
Getsinger, D., Gevorkyan, L., Smith, O. I. & Karagozian, A. R. 2014 Structural and stability characteristics of jets in crossflow. J. Fluid Mech. 760, 342–367.Google Scholar
Getsinger, D. R., Hendrickson, C. & Karagozian, A. R. 2012 Shear layer instabilities in low-density transverse jets. Exp. Fluids 53, 783–801.Google Scholar
Gevorkyan, L.2015 Structure and mixing characterization of variable density transverse jet flows. PhD thesis, UCLA.Google Scholar
Ghandhi, J. B. 2006 Spatial resolution and noise considerations in determining scalar dissipation rate from passive scalar image data. Exp. Fluids 40, 577–588.CrossRefGoogle Scholar
Hasselbrink, E. F.1999 Transverse jets and jet flames: structure, scaling, and effects of heat release. PhD thesis, Stanford University.Google Scholar
Hasselbrink, E. F. & Mungal, M. G. 2001 Transverse jets and jet flames. Part 1. Scaling laws for strong transverse jets. J. Fluid Mech. 443, 1–25.CrossRefGoogle Scholar
Hendrickson, C. & M’Closkey, R. 2012 Phase compensation strategies for modulated–demodulated control with application to pulsed jet injection. ASME J. Dyn. Syst. Meas. Control 134, 011024.Google Scholar
Hermanson, J. C., Mungal, M. G. & Dimotakis, P. E. 1987 Heat release effects on shear-layer growth and entrainment. AIAA J. 25 (4), 578–583.CrossRefGoogle Scholar
Holdeman, J. D. 1993 Mixing of multiple jets in a confined subsonic crossflow. Prog. Energy Combust. Sci. 19 (1), 31–70.Google Scholar
Huerre, P. & Monkewitz, P. A. 1990 Local and global instabilities in spatially developing flows. Annu. Rev. Fluid Mech. 22, 473–537.Google Scholar
Jendoubi, S. & Strykowski, P. J. 1994 Absolute and convective instability of axisymmetric jets with external flow. Phys. Fluids 6, 3000–3009.CrossRefGoogle Scholar
Juniper, M. P., Li, L. K. B. & Nichols, J. W. 2009 Forcing of self-excited round jet diffusion flames. Proc. Combust. Inst. 32, 1191–1198.CrossRefGoogle Scholar
Kamotani, Y. & Greber, I. 1972 Experiments on a turbulent jet in a cross flow. AIAA J. 10 (11), 1425–1429.Google Scholar
Karagozian, A. R. 1986 An analytical model for the vorticity associated with a transverse jet. AIAA J. 24, 429–436.CrossRefGoogle Scholar
Karagozian, A. R. 2010 Transverse jets and their control. Prog. Energy Combust. Sci. 36, 531–553.Google Scholar
Karagozian, A. R. & Marble, F. E. 1986 Study of a diffusion flame in a stretched vortex. Combust. Sci. Technol. 45 (1–2), 65–84.Google Scholar
Keffer, J. F. & Baines, W. D. 1963 The round turbulent jet in a cross-wind. J. Fluid Mech. 15 (4), 481–496.Google Scholar
Kelso, R. M., Lim, T. T. & Perry, A. E. 1996 An experimental study of round jets in cross-flow. J. Fluid Mech. 306, 111–144.Google Scholar
Kelso, R. M. & Smits, A. J. 1995 Horseshoe vortex systems resulting from the interaction between a laminar boundary layer and a transverse jet. Phys. Fluids 7, 153–158.CrossRefGoogle Scholar
Kuzo, D. M.1995 An experimental study of the turbulent transverse jet. PhD thesis, California Institute of Technology.Google Scholar
Lozano, A.1992 Laser-excited luminescent tracers for planar concentration measurements in gaseous jets. PhD thesis, Stanford University.Google Scholar
Lozano, A., Yip, B. & Hanson, R. K. 1992 Acetone: a tracer for concentration measurements in gaseous flows by planar laser-induced fluorescence. Exp. Fluids 13, 369–376.Google Scholar
Mahesh, K. & Iyer, P. 2013 Numerical study of shear layer instability in transverse jets. Bull. Am. Phys. Soc. 58 (18), 174.Google Scholar
Margason, R. J.1993 Fifty years of jet in cross flow research. AGARD-CP-534 1, 1–141.Google Scholar
M’Closkey, R. T., King, J., Cortelezzi, L. & Karagozian, A. R. 2002 The actively controlled jet in crossflow. J. Fluid Mech. 452, 325–335.Google Scholar
Megerian, S., Davitian, J., de B. Alves, L. S. & Karagozian, A. R. 2007 Transverse-jet shear-layer instabilities. Part 1. Experimental studies. J. Fluid Mech. 593, 93–129.Google Scholar
Moussa, Z. M., Trischka, J. W. & Eskinazi, S. 1977 The nearfield in the mixing of a round jet with a cross-stream. J. Fluid Mech. 80, 49–80.Google Scholar
Muppidi, S. & Mahesh, K. 2005 Study of trajectories of jets in crossflow using direct numerical simulations. J. Fluid Mech. 530, 81–100.Google Scholar
Muppidi, S. & Mahesh, K. 2007 Direct numerical simulation of round turbulent jets in crossflow. J. Fluid Mech. 574, 59–84.Google Scholar
Niederhaus, C. E., Champagne, F. H. & Jacobs, J. W. 1997 Scalar transport in a swirling transverse jet. AIAA J. 35 (11), 1697–1704.CrossRefGoogle Scholar
Shan, J. & Dimotakis, P. 2006 Reynolds-number effects and anisotropy in transverse-jet mixing. J. Fluid Mech. 566, 47–96.Google Scholar
Shapiro, S., King, J., M’Closkey, R. T. & Karagozian, A. R. 2006 Optimization of controlled jets in crossflow. AIAA J. 44, 1292–1298.Google Scholar
Smith, S. H. & Mungal, M. G. 1998 Mixing, structure and scaling of the jet in crossflow. J. Fluid Mech. 357, 83–122.Google Scholar
Srinivasan, V., Hallberg, M. P. & Strykowski, P. J. 2010 Viscous linear stability of axisymmetric low-density jets: parameters influencing absolute instability. Phys. Fluids 22, 024103.Google Scholar
Su, L. K. & Mungal, M. G. 2004 Simultaneous measurements of scalar and velocity field evolution in turbulent crossflowing jets. J. Fluid Mech. 513, 1–45.Google Scholar
Thurber, M. C., Grisch, F., Kirby, B. J., Votsmeier, M. & Hanson, R. K. 1998 Measurements and modeling of acetone laser-induced fluorescence with implications for temperature-imaging diagnostics. Appl. Opt. 37, 4963–4978.CrossRefGoogle ScholarPubMed