Trajectory Measurements of a Horizontally Oriented Buoyant Jet in a Coflow Using Filtered Rayleigh Scattering
Publication: Journal of Aerospace Engineering
Volume 30, Issue 1
Abstract
The filtered Rayleigh scattering technique was implemented to discern the mechanisms associated with trajectory and mixing characteristics of buoyant jets in the presence of a coflow. A continuous wave laser in conjunction with a high-speed camera and a molecular filter constituted the equipment needed to obtain near-field concentration measurements of a carbon dioxide jet within a coflow of air. The arrangement enabled carbon dioxide concentration measurements with and without the coflow at a sampling rate of 400 Hz. The time-averaged results demonstrate the significance that adding the coflow has on increasing the mixing rate, thus reducing the impact of the buoyant jet by flattening the jet trajectory. The effects of various flow parameters such as the jet velocity, the jet to coflow velocity ratio, the relative velocity between the jet and the coflow, and the Froude number on the jet trajectory are studied. The downward trajectory of the carbon dioxide jet, absent a coflow, was well correlated with the Froude number. However, the addition of the coflow led to a substantial impact on the jet trajectory, reducing its buoyant effects due to a combination of increased momentum and, likely, the mixing rate. Further increases in the coflow, including the relative magnitude of the coflow, had a lesser impact. Mixing characteristics and time-dependent jet motion were captured.
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Acknowledgments
The authors would also like to thank Jake Schmidt of Spectral Energies, LLC for his contribution in the setup of the laser diagnostic systems and Jay Anderson and John Hixenbaugh at AFIT for their support in setting up the experiment. The views expressed in this article are those of the authors and do not reflect the official policy or position of the United States Air Force, Department of Defense, or the U.S. Government.
References
Benhassen, F., Polanka, M. D., and Reeder, M. F. (2011). “Time resolved filtered Rayleigh scattering measurement of a buoyant jet in a co-flow.” 49th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition, AIAA, Reston, VA.
Bivolaru, D., Danehy, P., Lee, J., Gaffney, R., and Cutler, A. (2006). “Single-pulse multi-point multi-component interferometric Rayleigh scattering velocimeter.” 44th AIAA Aerospace Sciences Meeting, AIAA, Reston, VA.
Boguszko, M., and Elliott, G. S. (2005). “Property measurement utilizing atomic/molecular filter-based diagnostics.” Progr. Aerosp. Sci., 41(2), 93–142.
Cheung, B. H., and Hanson, R. K. (2010). “CW laser-induced fluorescence of toluene for time resolved imaging of gaseous flows.” Appl. Phys. B, 98(2), 581–591.
Clem, M. M., Mielke-Fagan, A. F., and Elam, K. A. (2010). “Study of Fabry-Perot Etalon stability and tuning for spectroscopic Rayleigh scattering.” 48th AIAA Aerospace Sciences Meeting, AIAA, Reston, VA.
Jenkins, T. P., and Desabrais, K. J. (2010). “Three components velocity field measurements near a parachute during a drop test.” 48th AIAA Aerospace Sciences Meeting, AIAA, Reston, VA.
Mielke, A. F., Elam, K. LA., and Clem, M. M. (2009). “Multiple-point mass flux measurement system using Rayleigh scattering.” 47th AIAA Aerospace Sciences Meeting, AIAA, Reston, VA.
Mielke, A. F., Seasholtz, R. G., Elam, K. A., and Panda, J. (2005). “Time-average measurement of velocity, density, temperature, and turbulence velocity fluctuations using Rayleigh and Mie scattering.” Exp. Fluids, 39(2), 441–454.
Miles, R. B., Lempert, W. R., and Forkey, J. N. (2001). “Laser Rayleigh scattering.” Meas. Sci. Tech., 12(5), R33–R51.
Reeder, M. F., Huffman, R. E., Branam, R. D., LeBay, K. D., and Meents, S. M. (2011). “Near-field development of gas-phase horizontal laminar jets with positive and negative buoyancy measured with filtered Rayleigh scattering.” Exp. Fluids, 50(6), 1455–1472.
Samimy, M., and Wernet, M. P. (2000). “Review of planar multiple-component velocimetry in high speed flows.” AIAA J., 38(4), 553–574.
Seasholtz, R. G., Buggele, A. E., and Reeder, M. F. (1997). “Flow measurements based on Rayleigh scattering and Fabry-Perot interferometer.” Opt. Lasers Eng., 27(6), 543–570.
Seasholtz, R. G., Zupanc, F. J., and Schneider, S. J. (1992). “Spectrally resolved Rayleigh scattering diagnostic for hydrogen-oxygen rocket plume studies.” J. Propul. Power, 8(5), 935–942.
Su, L. K., Helmer, D. B., and Brownell, C. J. (2010). “Quantitative planar imaging of turbulent buoyant jet mixing.” J. Fluid Mech., 643, 59–95.
Subbarao, E. (1989). “The effects of Reynolds number and Richardson number on the structure of a vertical co-flowing buoyant jet.” AIAA 20th Fluid Dynamics, Plasma Dynamics and Lasers Conf., AIAA, Reston, VA.
Sutton, J. A., Patton, R. A., Gabet, K. N., Jiang, N., and Lempert, W. (2010). “Towards high-repetition rate Rayleigh and Raman scattering imaging in turbulent jets and flames.” 48th AIAA Aerospace Sciences Meeting, AIAA, Reston, VA.
Wilson, J. D., Polanka, M. D., and Miranda, J. (2013). “Flame structure effects at high G-loading.” 49th Joint Propulsion Conf., AIAA, Reston, VA.
Xiao, J., Travis, J. R., and Breitung, W. (2009). “Boussinesq integral model for horizontal turbulent buoyant round jets.” Sci. Technol. Nucl. Inst., 2009(2009), 7.
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Published In
Journal of Aerospace Engineering
Volume 30 • Issue 1 • January 2017
Copyright
© 2016 American Society of Civil Engineers.
History
Received: Aug 24, 2015
Accepted: Apr 14, 2016
Published online: Jul 19, 2016
Discussion open until: Dec 19, 2016
Published in print: Jan 1, 2017
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