Hostname: page-component-cd9895bd7-gvvz8 Total loading time: 0 Render date: 2024-12-29T15:08:39.406Z Has data issue: false hasContentIssue false

Modelling circulation, impulse and kinetic energy of starting jets with non-zero radial velocity

Published online by Cambridge University Press:  19 February 2013

Michael Krieg
Affiliation:
Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, FL 32611, USA Institute for Networked Autonomous Systems, University of Florida, Gainesville, FL 32611, USA
Kamran Mohseni
Affiliation:
Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, FL 32611, USA Department of Electrical and Computer Engineering, University of Florida, Gainesville, FL 32611, USA Institute for Networked Autonomous Systems, University of Florida, Gainesville, FL 32611, USA

Abstract

The evolution of starting jet circulation, impulse and kinetic energy are derived in terms of kinematics at the entrance boundary of a semi-infinite axisymmetric domain. This analysis is not limited to the case of parallel jet flows; and the effect of non-zero radial velocity is specifically identified. The pressure distribution along the entrance boundary is also derived as it is required for kinetic energy modelling. This is done without reliance on an approximated potential function (i.e. translating flat plate), making it a powerful analytical tool for any axisymmetric jet flow. The pressure model indicates that a non-zero radial velocity is required for any ‘over-pressure’ at the nozzle exit. Jet flows are created from multiple nozzle configurations to validate this model. The jet is illuminated in cross-section, and velocity and vorticity fields are determined using digital particle image velocimetry (DPIV) techniques and circulation, impulse and kinetic energy of the jet are calculated from the DPIV data. A non-zero radial velocity at the entrance boundary has a drastic effect on the final jet. Experimental data showed that a specific configuration resulting in a jet with a converging radial velocity, with a magnitude close to 40 % of the axial velocity at its maximum, attains a final circulation which is 90–100 % larger than a parallel starting jet with identical volume flux and nozzle diameter, depending on the stroke ratio. The converging jet also attains a final impulse which is 70–75 % larger than the equivalent parallel jet and a final kinetic energy 105–135 % larger.

Type
Papers
Copyright
©2013 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Anderson, E. J. & Grosenbaugh, M. A. 2005 Jet flow in steadily swimming adult squid. J. Exp. Biol. 208, 11251146.Google Scholar
Bartol, I. K., Krueger, P. S., Stewart, W. J. & Thompson, J. T. 2009 Hydrodynamics of pulsed jetting in juvenile and adult brief squid Lolliguncula brevis: evidence of multiple jet ‘modes’ and their implications for propulsive efficiency. J. Exp. Biol. 11891903,doi:10.1093/icb/icn043.Google ScholarPubMed
Bartol, I. K., Krueger, P. S., Thompson, J. T. & Stewart, W. J. 2008 Swimming dynamics and propulsive efficiency of squids throughout ontogeny. Integr. Compar. Biol. 48 (6), 114.Google Scholar
Cantwell, B. J. 1986 Viscous starting jets. J. Fluid Mech. 173, 159189.Google Scholar
Dabiri, J. O. & Gharib, M. 2004 Fluid entrainment by isolated vortex rings. J. Fluid Mech. 511 (4), 311331.Google Scholar
Dabiri, J. O., Colin, S. P., Katija, K. & Costello, J. H. 2010 A wake based correlate of swimming performance and foraging behaviour in seven co-occurring jellyfish species. J. Exp. Biol. 213, 12171275.Google Scholar
Didden, N. 1979 On the formation of vortex rings: rolling-up and production of circulation. Z. Angew. Mech. Phys. 30, 101116.Google Scholar
Gharib, M., Rambod, E., Kheradvar, A., Sahn, D. J. & Dabiri, J. O. 2006 Optimal vortex formation as an index of cardiac health. Proc. Natl Acad. Sci. U.S.A. 103 (16), 63056308.Google Scholar
Gharib, M., Rambod, E. & Shariff, K. 1998 A universal time scale for vortex ring formation. J. Fluid Mech. 360, 121140.Google Scholar
Glezer, A. 1988 The formation of vortex rings. Phys. Fluids 12, 35323542.Google Scholar
Haller, G. & Yuan, G. 2000 Lagrangian coherent structures and mixing in two-dimensional turbulence. Physica D 147, 352370.Google Scholar
Holman, R., Utturkar, Y., Mittal, R., Smith, B. L. & Cattafesta, L. 2005 Formation criterion for synthetic jets. AIAA J. 43 (10), 21102116.Google Scholar
Krieg, M. & Mohseni, K. 2008 Thrust characterization of pulsatile vortex ring generators for locomotion of underwater robots. IEEE J. Ocean. Engng 33 (2), 123132.Google Scholar
Krueger, P. S. 2005 An over-pressure correction to the slug model for vortex ring circulation. J. Fluid Mech. 545, 427443.Google Scholar
Krueger, P. S. 2008 Circulation and trajectories of vortex rings formed from tube and orifice openings. Physica D 237, 22182222.Google Scholar
Krueger, P. S. & Gharib, M. 2003 The significance of vortex ring formation to the impulse and thrust of a starting jet. Phys. Fluids 15 (5), 12711281.Google Scholar
Krueger, P. S. & Gharib, M. 2005 Thrust augmentation and vortex ring evolution in a fully pulsed jet. AIAA J. 43 (4), 792801.Google Scholar
Lamb, H. 1945 Hydrodynamics. Dover.Google Scholar
Landau, L. D. & Lifshitz, E. M. 1959 Fluid mechanics. In Ideal Fluids (Energy Flux), pp. 910. Butterworth-Heinemann, chap. 1.6.Google Scholar
Lim, T. T. & Nickels, T. B. 1995 Vortex rings. In Fluid Vortices (ed. Green, S. I.). Kluwer.Google Scholar
Lipinski, D. & Mohseni, K. 2009a Flow structures and fluid transport for the hydromedusa Sarsia tubulosa. AIAA paper 2009-3974. 19th AIAA Computational Fluid Dynamics Conference, San Antonio, Texas. Curran Associates Inc.Google Scholar
Lipinski, D. & Mohseni, K. 2009b Flow structures and fluid transport for the hydromedusae Sarsia tubulosa and Aequorea victoria . J. Exp. Biol. 212, 24362447.Google Scholar
Mohseni, K. 2006 Pulsatile vortex generators for low-speed maneuvering of small underwater vehicles. Ocean Engng 33 (16), 22092223.Google Scholar
Mohseni, K. & Gharib, M. 1998 A model for universal time scale of vortex ring formation. Phys. Fluids 10 (10), 24362438.Google Scholar
Mohseni, K., Ran, H. & Colonius, T. 2001 Numerical experiments on vortex ring formation. J. Fluid Mech. 430, 267282.Google Scholar
Nitsche, M. & Krasny, R. 1994 A numerical study of vortex ring formation at the edge of a circular tube. J. Fluid Mech. 276, 139161.Google Scholar
Olcay, A. B. & Krueger, P. S. 2008 Measurement of ambient fluid entrainment during laminar vortex ring formation. Exp. Fluids 44 (2), 235247.Google Scholar
Pullin, D. I. 1979 Vortex ring formation in tube and orifice openings. Phys. Fluids 22, 401403.Google Scholar
Pullin, D. I. 1978 The large-scale structure of unsteady self-similar rolled-up vortex sheets. J. Fluid Mech. 88 (3), 401430.Google Scholar
Pullin, D. I. & Phillips, W. R. C. 1981 On a generalization of Kaden’s problem. J. Fluid Mech. 104, 4553.Google Scholar
Raffel, M., Willert, C. E. & Kompenhans, J. 1998 Particle Image Velocimetry. Springer.Google Scholar
Raju, R., Mittal, R., Gallas, Q. & Cattafesta, L. 2005 Scaling of vorticity flux and entrance length effects in zero-net mass-flux devices. In AIAA 35th Fluid Dynamics Conference and Exhibit. Toronto, Ontario. AIAA.Google Scholar
Richardson, E. G. & Tyler, E. 1929 The transverse velocity gradients near the mouth of a pipe in which an alternating or continuous flow of air is established. Proc. Phys. Soc. Lond. 42, 115.Google Scholar
Rosenfeld, M., Katija, K. & Dabiri, J. O. 2009 Circulation generation and vortex ring formation by conic nozzles. J. Fluids Engng 131, 091204.Google Scholar
Rosenfeld, M., Rambod, E. & Gharib, M. 1998 Circulation and formation number of laminar vortex rings. J. Fluid Mech. 376, 297318.Google Scholar
Saffman, P. G. 1978 The number of waves on unstable vortex rings. J. Fluid Mech. 84 (4), 625639.Google Scholar
Saffman, P. G. 1992 Vortex Dynamics. Cambridge University Press.Google Scholar
Sahin, M. & Mohseni, K. 2008 The numerical simulation of flow patterns generated by the hydromedusa Aequorea victoria using an arbitrary Lagrangian–Eulerian formulation. AIAA paper 2008-3715. 38th AIAA Fluid Dynamics Conference and Exhibit, Seattle, OR. Curran Associates Inc.Google Scholar
Sahin, M. & Mohseni, K. 2009 An arbitrary Lagrangian–Eulerian formulation for the numerical simulation of flow patterns generated by the hydromedusa Aequorea victoria . J. Comp. Phys. 228, 45884605.Google Scholar
Sahin, M., Mohseni, K. & Colins, S. 2009 The numerical comparison of flow patterns and propulsive performances for the hydromedusae Sarsia tubulosa and Aequorea victoria . J. Exp. Biol. 212, 26562667.Google Scholar
Sexl, T. 1930 Uber den von E.G. Righardson entdeckten ‘Annulareffekt’. Z. Phys. 61, 349362.Google Scholar
Shadden, S. C., Lekien, F. & Marsden, J. E. 2005 Definition and properties of Lagrangian coherent structures from finite time Lyapunov exponents in two-dimensional aperiodic flows. Physica D 212, 271304.Google Scholar
Shariff, K. & Leonard, A. 1992 Vortex rings. Annu. Rev. Fluid Mech. 34, 235279.Google Scholar
Szymanski, F. 1932 Quelques solutions exactes des équations de l’hydrodynamiquede fluide visqueux dans le cas d’un tube cylindrique. J. Math. Pures Appl. 11 (9), 67107.Google Scholar
White, F. M. 2006 Viscous Fluid Flow, 3rd edn. McGraw-Hill.Google Scholar
Willert, C. E. & Gharib, M. 1991 Digital particle image velocimetry. Exp. Fluids 10, 181193.CrossRefGoogle Scholar