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Organized motions in a fully developed turbulent axisymmetric jet

Published online by Cambridge University Press:  26 April 2006

Jin Tso  and
Fazle Hussain
Jin Tso
Affiliation:
Department of Mechanical Engineering, University of Houston, TX 77004, USA Present address: Aeronautical Engineering Department, California Polytechnic State University, San Luis Obispo, CA 93407, USA.
Fazle Hussain
Affiliation:
Department of Mechanical Engineering, University of Houston, TX 77004, USA
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Abstract

An experiment has been conducted to study the occurrence, configuration and dynamics of large-scale coherent vortical motions in the fully developed region of a turbulent axisymmetric jet. The key idea is to use vorticity signals from a spatial grid to detect and sample large-scale vortical structures and then use the (smoothed) vorticity peaks of spatial vorticity patterns to align and ensemble average successive realizations to determine structure configuration and dynamics. Measurements were made in an air jet at ReD = 69000 by employing a radial rake of seven × -wires to obtain the azimuthal vorticity map. Two additional conditioning probes were placed ± 90° away from the rake to determine the three-dimensional phase and hence the structure configuration. Structures with axisymmetric, helical and double helical configurations have been educed. Among them, the helical structures are far more dominant than the others, and the jet dynamics are thus discussed in terms of these helical structures. Helical structures move radially outward as they advect downstream. This radial movement, in conjunction with simultaneous local ejection of turbulent fluid and subsequent entrainment of the ejected fluid with ambient fluid, appears to be a major means of jet spreading. The shear strain rate is strong on the downstream side of the structure, causing intense small-scale turbulence production and mixing there.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 203 , June 1989 , pp. 425 - 448
Copyright
© 1989 Cambridge University Press

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References

Batchelor, G. K. & Gill, A. E., 1962 Analysis of the stability of axisymmetric jets. J. Fluid Mech. 14, 529–551.Google Scholar
Bernal, L. P. & Roshko, A., 1986 Streamwise vortex structure in plane mixing layers. J. Fluid Mech. 170, 499–525.Google Scholar
Blackwelder, R. F. & Kaplan, R. E., 1976 On the wall structure of the turbulent boundary layer. J. Fluid Mech. 76, 89–112.Google Scholar
Browand, F. K. & Troutt, T. R., 1980 A note on spanwise structure in the two-dimensional mixing layer. J. Fluid Mech. 97, 771–781.Google Scholar
Browand, F. K. & Weidman, P. D., 1976 Large scales in the developing mixing layer. J. Fluid Mech. 76, 127–144.Google Scholar
Cantwell, B. J.: 1981 Organized motion in turbulent flow. Ann. Rev. Fluid Mech. 13, 457–515.Google Scholar
Chevray, R. & Tutu, N. K., 1978 Intermittency and preferential transport of heat in a round jet. J. Fluid Mech. 88, 133–160.Google Scholar
Coles, D.: 1981 Prospects for useful research on coherent structure in turbulent shear flow. Proc. Indian Acad. Sci. 4, 111–128.Google Scholar
Crow, S. C. & Champagne, F. H., 1971 Orderly structure in jet turbulence. J. Fluid Mech. 48, 547–591.Google Scholar
Dimotakis, P. E., Miake-lye, R. L. & Papantoniou, D. A. 1983 Structure and dynamics of round turbulent jets. Phys. Fluids 26, 3185–3192.Google Scholar
Gupta, A. K., Laufer, J. & Kaplan, R. E., 1971 Spatial structure in the viscous sublayer. J. Fluid Mech. 50, 493–512.Google Scholar
Hayakawa, M.: 1985 Eduction of coherent structures in the turbulent plane wake. In Proc. 5th Symp. on Turbulent Shear Flows, Cornell University, pp. 433–438. Springer.
Hussain, A. K. M. F.: 1980 Coherent structures in perturbed and unperturbed jets. In Lecture Notes in Physics, vol. 136, pp. 252–291. Springer.
Hussain, A. K. M. F. & Clark, A. R. 1981a Measurements of wavenumber celerity spectrum in plane and axisymmetric jets. AIAA J. 19, 51–55.Google Scholar
Hussain, A. K. M. F. & Clark, A. R. 1981b On the coherent structure of the axisymmetric mixing layer: a flow-visualization study. J. Fluid Mech. 104, 262–294.Google Scholar
Hussain, A. K. M. F. & Zaman, K. B. M. Q. 1982 The organized motions in the turbulent plane mixing layer. Rep. FM-14. University of Houston. See also J. Fluid Mech. 159, 85 (1985).
Kibens, V.: 1980 Discrete noise spectrum generated by an acoustically excited jet. AIAA J. 18, 434–441.Google Scholar
Konrad, J. H.: 1976 An experimental investigation of mixing in two-dimensional turbulent shear flows with applications to diffusion limited chemical reactions. Intern. Rep. CIT-8-PU. California Institute of Technology.
Lin, C. C.: 1953 On Taylor's hypothesis in wind tunnel turbulence. Q. Appl. Maths 10, 295–306.Google Scholar
Lumley, J. L.: 1981 Coherent structures in turbulence. In Transition and Turbulence (ed. J. Th. Meyer), pp. 215–242. Academic.
Morris, P. J.: 1976 The spatial viscous instability of axisymmetric jets. J. Fluid Mech. 77, 511–529.Google Scholar
Oshima, Y. & Asaka, S., 1977 Interaction of two vortex rings along parallel axes in air. J. Phys. Soc. Japan 42, 708–713.Google Scholar
Reynolds, A. J.: 1962 Observations of a liquid-into-liquid jet. J. Fluid Mech. 14, 552–556.Google Scholar
Sreenivasan, K. R.: 1984 The azimuthal correlations of velocity and temperature fluctuations in an axisymmetric jet. Phys. Fluids 27, 867–875.Google Scholar
Strange, P. J. R. & Crighton, D. G. 1983 Spinning modes on axisymmetric jets. J. Fluid Mech. 134, 231–245.Google Scholar
Tso, J.: 1983 Coherent structures in a fully-developed turbulent axisymmetric jet. Ph.D. thesis, Johns Hopkins University.
Tso, J., Kovasznay, L. S. G. & Hussain, A. K. M. F. 1981 Search for large-scale coherent structures in the nearly self-preserving region of a turbulent axisymmetric jet. Trans. ASME I: J. Fluids Engng 103, 503–508.Google Scholar
Wygnanski, I. & Fiedler, H., 1969 Some measurements in the self-preserving jet. J. Fluid Mech 38, 577–612.Google Scholar
Zaman, K. B. M. Q. & Hussain, A. K. M. F. 1980 Vortex pairing in a circular jet under controlled excitation: part 1, general jet response. J. Fluid Mech. 101, 449–491.Google Scholar
Zaman, K. B. M. Q. & Hussain, A. K. M. F. 1981 Taylor hypothesis and large-scale coherent structures. J. Fluid Mech. 112, 379–396.Google Scholar