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Topological Flow Structures of Annular Swirling Jets

Published online by Cambridge University Press:  05 May 2011

Feng Chin Tsai  and
Rong Fung Huang
Feng Chin Tsai*
Affiliation:
Department of Mechanical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan 10672, R.O.C.
Rong Fung Huang*
Affiliation:
Department of Mechanical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan 10672, R.O.C.
*
*Graduate student
**Professor
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Abstract

The effects of blockage and swirl on the macro flow structures of the annular jet past a circular disc are experimentally studied through the time-averaged streamline patterns. In the blockage-effect regime, the flows present multiple modes, single bubble, dual rings, vortex breakdown, and triple rings, in different regimes of blockage ratio and swirl number. The topological models of the flow structures are proposed and discussed according to the measured flow fields to manifest the complex flow structures. The single bubble is a closed recirculation bubble with a stagnation point on the central axis. The dual-ring flow is an open-top recirculsation zone, in which a pair of counter-rotating vortex rings exists in the near wake. The fluids in the dual rings are expelled downstream through a central jet-like swirling flow. A vortex breakdown may occur in the central jet-like swirling flow if the exit swirl number exceeds critical values. When the vortex breakdown interacts with the dual rings, a complex triple-ring flow structure forms. Axial distributions of the local swirl number are presented and discussed. The local swirl number increases with the increase of the exit swirl number and attains the maximum in the dual-ring mode. At large exit swirl numbers where the vortex breakdown occurs, the local swirl number decreases drastically to a low value.

Keywords

Swirling wakeVortex breakdownRecirculation bubble
Type
Articles
Information
Journal of Mechanics , Volume 17 , Issue 3 , September 2001 , pp. 131 - 138
Copyright
Copyright © The Society of Theoretical and Applied Mechanics, R.O.C. 2001

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References

REFERENCES

1.Gupta, A. K., Lilley, D. G. and Syred, N., Swirl Flows, Abacus Press, Cambridge, pp. 13–117 (1984).Google Scholar
2.Chigier, N. A. and Beer, J. M., “Velocity and Static Pressure Distributions in Swirling Air Jets Issuing from Annular and Divergent Nozzles,” Trans. ASME, Series D, 86, pp. 788–798 (1964).CrossRefGoogle Scholar
3.Kerr, N. M. and Fraser, D., “Swirl, Part 1: Effect on Axisymmetrical Turbulent Jets,” J. Institute Fuel, 38, pp. 519–526 (1965).Google Scholar
4.Chigier, N. A. and Chervinsky, A., “Experimental Investigation of Swirling Vortex Motions in Jets,” J. Appl. Mech., 89, pp. 443–451 (1967).CrossRefGoogle Scholar
5.Baker, R. J., Hutchinson, P., Khallil, E. E. and Whitelaw, J. H., “Measurements of Three Velocity Components in a Model Furnace with and without Combustion,” Fifteenth Symposium (International) on Combustion, The Combustion Institute, Pittsburgh, pp. 553–559 (1974).Google Scholar
6.Escudier, M. P. and Keller, J. J., “Recirculation in Swirling Flow: a Manifestation of Vortex Breakdown,” AIAA Journal, 23, pp. 111–116 (1985).CrossRefGoogle Scholar
7.Harvey, J. K., “Some Observation of the Vortex Breakdown Phenomenon,” J. Fluid Mech., 14, pp. 585–592 (1962).CrossRefGoogle Scholar
8.Faler, J. H. and Leibovich, S., “An Experimental Map of the Internal Structure of a Vortex Breakdown,” J. Fluid Mech., 86, pp. 313–335 (1978).CrossRefGoogle Scholar
9.Sheen, H. J., Chen, W. J. and Jeng, S. Y., “Recirculation Zones of Unconfined and Confined Annular Swirling Jets,” AIAA Journal, 34, pp. 572–579 (1996).CrossRefGoogle Scholar
10.Heywood, J. B., Internal Combustion Engine Fundamentals, McGraw-Hill, New York, pp. 326–353 (1988).Google Scholar
11.Ekchian, A. and Hoult, D. P., “Flow Visualization Study of the Intake Process of an Internal Combustion Engine,” SAE Paper 800044 (1979).CrossRefGoogle Scholar
12.Nadarajah, S., Balabani, S., Tindal, M. J. and Yianneskis, M., “The Effect of Swirl on the Annular Flow Past an Axisymmetric Poppet Valve,” Journal of Mechanical Engineering Science, IMechE Part C, 212, pp. 473–484 (1997).CrossRefGoogle Scholar
13.Perry, A. E. and Fairlie, B. D., “Critical Points in Flow Patterns,” Adv. Geophys. B, 18, pp. 299–315 (1974).CrossRefGoogle Scholar
14.Chong, M. S. and Perry, A. E., “A General Classification of Three-Dimensional Flow Fields,” Phys. Fluids A, 2, pp. 765–777 (1990).CrossRefGoogle Scholar
15.Flagan, R. C. and Seinfeld, J. H., Fundamentals of Air Pollution Engineering, Prentice Hall, Englewood Cliffs, New Jersey, pp. 290–357 (1988).Google Scholar
16.Hjelmfelt, A. T. and Mockros, L. F., “Motion of Discrete Particles in a Turbulent Fluid,” AIAA J., 16, pp. 149–154 (1966).Google Scholar
17.Farokhi, S. and Taghavi, R., “Effect of Initial Swirl Distribution on the Evolution of a Turbulent Jet,” AIAA Journal, Vol.27, pp. 700–706 (1989).CrossRefGoogle Scholar
18.Haile, E., Delabray, D., Durox, D., Lacas, F. and Candel, S., “Combustion Enhancement by Active Control,” Flow Control — Fundamentals and Practices, Gad-el-Hak, M., Pollard, A. and Bonnet, J. P., Springer-Verlag, Berlin, pp. 467–499 (1998).Google Scholar
19.Lighthill, M. J., Laminar Boundary Layers, Oxford University Press, Cambridge, pp. 48–88 (1963).Google Scholar
20.Perry, A. E. and Steiner, T. R., “Large-Scale Vortex Structures in Turbulent Wakes behind Bluff Bodies, Part 1, Vortex Formation,” J. Fluid Mech., 174, pp. 233–270 (1987).CrossRefGoogle Scholar
21.Perry, A. E., Chong, M. S. and Lim, T. T., “The Vortex-Shedding Process Behind Two-Dimensional Bluff B1odies,” J. Fluid Mech., 116, pp. 77–90 (1982).CrossRefGoogle Scholar
22.Hunt, J. C. R., Abell, C. J., Peterka, J. A. and Woo, H., “Kinematical Studies of the Flows Around Free or Surface-Mounted Obstacles; Applying Topology to Flow Visualization,” J. Fluid Mech., 86, pp. 299–446 (1978).CrossRefGoogle Scholar
23.Sarpkaya, T., “On Stationary and Traveling Vortex Breakdown,” J. Fluid Mech., 45, pp. 545–559 (1971).CrossRefGoogle Scholar