Experimental Investigation of Breakup Characteristics of Elliptical, Rectangular and Circular Water Jets

Document Type : Original Article

Authors

Amirkabir University of Technology

Abstract

In this study, the instabilities of elliptical, rectangular and circular water jets were experimentally investigated. Shadowgraph technique was employed to capture the jet column status instantaneously. Jet parameters such as disintegration length and axis switching wavelength were quantitatively studied. The results showed that due to the similar characteristics of rectangular and elliptical jets, their breakup length in the second wind-induced regime is nearly equal, while the breakup length of circular jet is perceptibly shorter. Both rectangular and elliptical jets are affected by aerodynamic forces sooner and thus enter the first wind induced regime at lower velocities. Furthermore, it was revealed that the axis switching wavelength is not dependent upon the jet geometry at low Weber numbers and remains equal for both elliptical and rectangular jets. However, at high Weber numbers, the axis switching wavelength of rectangular jet become larger than the elliptical one. Based on the obtained results, a semi-empirical relation was proposed to predict the axis switching wavelength of rectangular and elliptical jets.

Keywords


1. Savart, F., "Memoire Sur la Constitution des Veines Liquides Lancees par des Orifices Circulaires en Mince Paroi", Ann. Chim. Phys, Vol. 53, No. 337, (1833).
2. Plateau, J., "Statique Experimentale et. Theorique des Liquids Soumie aux Seules Forces", Cauthier Villars, Paris, Vol. 1 & 2, pp. 450-495, (1873).
3. Rayleigh, L., "On the Instability of Jets", Proc. R. Soc. London, Vol. 10, pp. 4-13, (1878).
4. Rayleigh, L., "On the Capillary Pheomena of Jets", Proc. R. Soc. London, Vol. 29, pp. 71-97, (1879).
5. Weber, C., "Zum Zerfall Eines Flüssigkeitsstrahles", ZAMM‐Journal of Applied Mathematics and Mechanics/Zeitschrift für Angewandte Mathematik und Mechanik, Vol. 11, No. 2, pp. 136-154, (1931).
6. Taylor, G.I., "Generation of Ripples by Wind Blowing over Viscous Fluids", In The Scientific Papers of G.I. Taylor, ed. GK Batchelor, Cambridge Univ., Vol. 3, pp. 244-254, (1962).
7. Bogy, D.B., "Drop Formation in a Circular Liquid Jet", Annual Review of Fluid Mechanics, Vol. 11, No. 1, pp. 207-228, (1979).
8. Reitz, R.D., "Mechanisms of Breakup of Round Liquid Jets", Encyclopedia of Fluid Mechanics, Vol. 3, pp. 233-249, (1986).
9. Lin, S.P. and Reitz, R.D., "Drop and Spray Formation from a Liquid Jet", Annual Review of Fluid Mechanics, Vol. 30, No. 1, pp. 85-105, (1998).
10. Birouk, M. and Lekic, N. "Liquid Jet Breakup in Quiescent Atmosphere: A Review", Atomization and Sprays, Vol. 19, No. 6, pp. 501-528, (2009).
11. Gutmark, E.J. and Grinstein, F.F., "Flow Control with Noncircular Jets", Annual Review of Fluid Mechanics, Vol. 31, No. 1, pp. 239-272, (1999).
12. Wang, F. and Fang, T., "Liquid Jet Breakup for Non-circular Orifices under Low Pressures", International Journal of Multiphase Flow, Vol. 72, pp. 248-262, (2015).
13. Magnus, G., "Hydraulische Untersuchungen", Ann. Phys., Vol. 171, pp. 1-59, (1855).
14. Kasyap, T.V., Sivakumar, D. and Raghunandan, B.N., "Breakup of Liquid Jets Emanating from Elliptical Orifices at Low Flow Conditions", Atomization and Sprays, Vol. 18, No. 7, pp. 1-24, (2008).
15. Kasyap, T.V., Sivakumar, D. and Raghunandan, B.N. "Flow and Breakup Characteristics of Elliptical Liquid Jets", International Journal of Multiphase Flow, Vol. 35, No. 1, pp. 8-19, (2009).
16. Amini, G. and Dolatabadi, A., "Axis-switching and Breakup of Low-speed Elliptic Liquid Jets", International Journal of Multiphase Flow, Vol. 42, pp. 96-103, (2012).
17. Sharma, P. and Fang, T., "Breakup of Liquid Jets from Non-circular Orifices", Experiments in Fluids, Vol. 55, No. 2, pp. 1-17, (2014).
18. Konkachbaev, A.I., Morley, N.B., Gulec, K. and Sketchley, T., "Stability and Contraction of a Rectangular Liquid Metal Jet in a Vacuum Environment", Fusion Engineering and Design, Vol. 51, pp. 1109-1114, (2000).
19. Negeed, E.S.R., Hidaka, S., Kohno, M. and Takata, Y., "Experimental and Analytical Investigation of Liquid Sheet Breakup Characteristics", International Journal of Heat and Fluid Flow, Vol. 32, pp.
95-106, (2011).
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