Reynolds Number Effects on the Near-Exit Region of Turbulent Jets
Publication: Journal of Hydraulic Engineering
Volume 136, Issue 9
Abstract
In this paper, attention has been focused on the near-exit region of a round turbulent free jet to study the large-scale coherent structures and to document the signatures of the vortices over a range of Reynolds numbers. Particle image velocimeter measurements were conducted at three jet exit Reynolds numbers of 10,000, 30,000, and 55,000. The large-scale structures in the near field were investigated by performing a proper orthogonal decomposition analysis of the velocity fields. A vortex identification algorithm was complemented by swirling strength maps to identify the vortex centers, rotational sense, size, and circulation of the vortices. The influence of the Reynolds number on the distribution of the number, size, and circulation of the identified vortices was studied. Proper orthogonal decomposition of the velocity fields revealed that Reynolds number has a strong influence on the mean circulation of vortices. The present results show that the axial location where vortices first appear and the number of vortices close to the nozzle exit are dependent on the Reynolds number.
Get full access to this article
View all available purchase options and get full access to this article.
References
Adrian, R. J., Christensen, K. T., and Liu, Z. C. (2000). “Analysis and interpretation of instantaneous turbulent velocity fields.” Exp. Fluids, 29, 275–290.
Agrawal, A., and Prasad, A. K. (2002). “Properties of vortices in the self-similar turbulent jet.” Exp. Fluids, 33, 565–577.
Bey, A., Faruque, M. A. A., and Balachandar, R. (2007). “Two-dimensional scour hole problem: Role of fluid structures.” J. Hydraul. Eng., 133(4), 414–430.
Brown, G. L., and Roshko, A. (1974). “On density effects and large structure in turbulent mixing layers.” J. Fluid Mech., 64, 775–816.
Dimotakis, P. E., Miake-Lye, R. C., and Papantoniou, D. A. (1983). “Structure and dynamics of round turbulent jets.” Phys. Fluids, 26, 3185–3192.
Faruque, M. A. A. (2004). “Transient local scour by submerged three-dimensional wall jets: Effect of tailwater depth.” MASc thesis, Dept. of Civil and Environmental Engineering, Univ. of Windsor, Windsor, Canada.
Fiedler, H. E. (1988). “Coherent structures in turbulent flows.” Prog. Aerosp. Sci., 25, 231–269.
Forliti, D. J., Strykowski, P. J., and Debatin, K. (2000). “Bias and precision errors of digital particle image velocimetry.” Exp. Fluids, 28, 436–447.
Ganapathisubramani, B., Longmire, E. K., and Marusic, I. (2002). “Investigation of three dimensionality in the near field of a round jet using stereo PIV.” J. Turbul., 3, 1–10.
Gutmark, E. J., Parr, T. P., Hanson-Parr, D. M., and Schadow, K. C. (1990). “Coherent and random structure in interacting jets.” Exp. Fluids, 10, 147–156.
Holmes, P., Lumley, J. L., and Berkooz, G. (1996). Turbulence, coherent structures, dynamical systems and symmetry, Cambridge University Press, New York.
Hussain, A. K. M. F. (1983). “Coherent structures—Reality and myth.” Phys. Fluids, 26, 2816–2850.
Hussain, A. K. M. F., and Zedan, M. F. (1978). “Effects of the initial condition on the axisymmetric free shear layer: Effect of the initial fluctuation level.” Phys. Fluids, 21, 1475–1481.
Hussein, H. J., Capp, S. P., and George, W. K. (1994). “Velocity measurements in a high-Reynolds-number, momentum-conserving, axisymmetric, turbulent jet.” J. Fluid Mech., 258, 31–75.
Longmire, E. K., and Eaton, J. K. (1992). “Structure of a particle-laden round jet.” J. Fluid Mech., 236, 217–257.
Prasad, A. K., Adrian, R. J., Landreth, C. C., and Offutt, P. W. (1992). “Effect of resolution on the speed and accuracy of particle image velocimetry interrogation.” Exp. Fluids, 13, 105–116.
Raffel, M., Willert, C., and Kompenhans, J. (1998). Particle image velocimetry: A practical guide, Springer, Berlin.
Rajaratnam, N. (1976). Turbulent jets, Elsevier Science, Amsterdam, The Netherlands.
Shinneeb, A. M. (2006). “Confinement effects in shallow water jets.” Ph.D. thesis, Dept. of Mechanical Engineering, Univ. of Saskatchewan, Saskatoon, Canada.
Shinneeb, A. M., Balachandar, R., and Bugg, J. D. (2008a). “Analysis of coherent structures in the far-field region on an axisymmetric free jet identified using particle image velocimeter and proper orthogonal decomposition.” ASME Trans. J. Fluids Eng., 130, 011202.
Shinneeb, A. M., Bugg, J. D., and Balachandar, R. (2004). “Variable threshold outlier identification in PIV data.” Meas. Sci. Technol., 15, 1722–1732.
Shinneeb, A. M., Bugg, J. D., and Balachandar, R. (2008b). “Quantitative investigation of vortical structures in the near exit region of an axisymmetric turbulent jet.” J. Turbul., 9, 1–20.
Sirovich, L. (1987). “Turbulence and the dynamics of coherent structures. Part I: Coherent structures.” Q. Appl. Math., 45, 561–571.
Tandalam, A. (2008). “Effect of Reynolds number on the characteristics of coherent structures in free round jets.” MASc thesis, Dept. of Mechanical, Automotive and Materials Engineering, Univ. of Windsor, Windsor, Canada.
Tso, J. (1984). “Coherent structures in a fully developed turbulent axisymmetric jet.” Ph.D. thesis, Dept. of Mechanical Engineering, The Johns Hopkins Univ., Baltimore.
Wygnanski, I., and Fiedler, H. (1969). “Some measurements in the self-preserving jet.” J. Fluid Mech., 38, 577–612.
Information & Authors
Information
Published In
Journal of Hydraulic Engineering
Volume 136 • Issue 9 • September 2010
Pages: 633 - 641
Copyright
© 2010 ASCE.
History
Received: Aug 5, 2008
Accepted: Mar 19, 2010
Published online: Mar 27, 2010
Published in print: Sep 2010
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.