Hostname: page-component-cd9895bd7-jkksz Total loading time: 0 Render date: 2024-12-25T15:43:23.761Z Has data issue: false hasContentIssue false
  • English
  • Français

The flow structure of a bubble-driven liquid-metal jet in a horizontal magnetic field

Published online by Cambridge University Press:  07 March 2007

C. ZHANG ,
S. ECKERT  and
G. GERBETH
C. ZHANG
Affiliation:
Forschungszentrum Dresden-Rossendorf e.V., PO Box 510119, 01314 Dresden, [email protected]
S. ECKERT
Affiliation:
Forschungszentrum Dresden-Rossendorf e.V., PO Box 510119, 01314 Dresden, [email protected]
G. GERBETH
Affiliation:
Forschungszentrum Dresden-Rossendorf e.V., PO Box 510119, 01314 Dresden, [email protected]
Get access Rights & Permissions [Opens in a new window]

Abstract

Static magnetic fields are known to be suitable for damping mean flow and turbulent motion in an electrically conducting liquid. In this paper, an experimental study is presented considering the influence of a horizontal magnetic field on a bubble-driven flow of a liquid metal. The investigation is focused on the liquid circulation inside a liquid metal column driven by a central jet produced by gas injection. The fluid vessel has a circular cross-section and electrically insulating walls. Low gas flow rates were applied, resulting in a plume of separated bubbles rising inside a spot around the cylinder axis. This axisymmetric configuration is exposed to a horizontal magnetic field. We present detailed experimental data describing the spatial as well as the temporal structure of the velocity field. Measurements of the vertical and the radial velocity component, respectively, were performed using the ultrasound Doppler velocimetry (UDV), allowing for the first time a complete mapping of the liquid velocity distribution for a bubble-driven liquid metal flow. The magnetic field considerably modified the global and local properties of the flow field compared to an ordinary bubble plume. In the parameter range considered here we did not find a prior flow suppression, but, in fact, a restructuring of the convective motion. The original axisymmetric flow field became anisotropic with respect to the direction of the magnetic field lines. An upwards flow dominated in a plane parallel to the magnetic field, whereas the recirculating motion was enforced in the orthogonal plane. Contrary to usual expectations, the application of a moderate magnetic field (100 < Ha < 400, 1 ≲ N ≲ 10) destabilizes the global flow and gives rise to transient, oscillating flow patterns with predominant frequencies.

Type
Papers
Information
Journal of Fluid Mechanics , Volume 575 , March 2007 , pp. 57 - 82
Copyright
Copyright © Cambridge University Press 2007

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

REFERENCES

Authie, G., Tagawa, T. & Moreau, R. 2003 Buoyant flow in long vertical enclosures in the presence of a strong horizontal magnetic field. Part 2. Finite enclosures. Eur. J. Mech. B/Fluids 22, 203–220.Google Scholar
Becker, S., DeBie, H. Bie, H. & Sweeney, J. 1999 Dynamic flow behaviour in bubble columns. Chem. Engng Sci. 54, 4929–4935.CrossRefGoogle Scholar
Borchers, O., Busch, C., Sokolichin, A. & Eigenberger, G. 1999 Applicability of the standard k-ϵ turbulence model to the dynamic simulation of bubble columns. Part II. Comparison of detailed experiments and flow simulations. Chem. Engng Sci. 54, 5927–5935.CrossRefGoogle Scholar
Brito, D., Nataf, H. C., Cardin, P., Aubert, J. & Masson, J. P. 2001 Ultrasonic Doppler velocimetry in liquid gallium. Exps. Fluids 31, 653–663.CrossRefGoogle Scholar
Burr, U. & Müller, U. 2001 Rayleigh–Bénard convection in liquid metal layers under the influence of a vertical magnetic field. Phys. Fluids 13, 3247–3257.CrossRefGoogle Scholar
Burr, U. & Müller, U. 2002 Rayleigh–Bénard convection in liquid metal layers under the influence of a horizontal magnetic field. J. Fluid Mech. 453, 345–369.Google Scholar
Burr, U., Barleon, P., Jochmann, P. & Tsinober, A. 2003 Magnetohydrodynamic convection in a vertical slot with horizontal magnetic field. J. Fluid Mech. 475, 21–40.CrossRefGoogle Scholar
Cramer, A., Zhang, C. & Eckert, S. 2004 Local structures in liquid metals measured by ultrasonic Doppler velocimetry. Flow Meas. Instrum. 15, 145–153.CrossRefGoogle Scholar
Davidson, P. A. 1995 Magnetic damping of jets and vortices. J. Fluid Mech. 299, 153–186.CrossRefGoogle Scholar
Davidson, P. A. 2001 An Introduction to Magnetohydrodynamics. Cambridge University Press.Google Scholar
Eckert, S. & Gerbeth, G. 2002 Velocity measurements in liquid sodium by means of ultrasound Doppler velocimetry. Exps. Fluids 32, 542–546.CrossRefGoogle Scholar
Eckert, S., Gerbeth, G. & Lielausis, O. 2000 The behavior of gas bubbles in a turbulent liquid metal magnetohydrodynamic flow. Part I. Dispersion in quasi-two-dimensional magnetohydrodynamic turbulence. Intl J. Multiphase Flow 26, 45–66.CrossRefGoogle Scholar
Eckert, S., Gerbeth, G. & Lielausis, O. 2000 The behavior of gas bubbles in a turbulent liquid metal magnetohydrodynamic flow. Part II. Magnetic field influence on the slip ratio. Intl J. Multiphase Flow 26, 67–82.CrossRefGoogle Scholar
Fauve, S., Laroche, C., Libchaber, A. & Perrin, B. 1984 Chaotic phases and magnetic order in convective fluid. Phys. Rev. Lett. 52, 1774–177111–122.7.Google Scholar
Iguchi, M., Demoto, Y., Sugawara, N. & Morita, Z. 1992 Bubble behavior in Hg-air vertical bubbling jets in a cylindrical vessel. ISIJ Intl 32, 998–1005.Google Scholar
Iguchi, M., Tsuji, Y., Mizuno, T., Mashiko, T., Sano, M. Kawabata, H., Ito, Y., NakaJima, K. & Morita, Z. 1994 Continuous measurements of bubble characteristics in a molten iron bath with Ar gas injection. ISIJ Intl 34, 980–985.Google Scholar
Kuwagi, K. & Ozoe, H. 1999 Three-dimensional oscillation of bubbly flow in a vertical cylinder. Intl J. Multiphase Flow 25, 175–182.Google Scholar
Leitch, A. M. & Baines, W. D. 1989 Liquid volume flux in a weak bubble plume. J. Fluid Mech. 205, 77–98.Google Scholar
Milgram, J. H. 1983 Mean flow in round bubble plumes. J. Fluid Mech. 133, 345–376.Google Scholar
Mudde, R. F. 2005 Gravity-driven bubbly flows. Annu. Rev. Fluid. Mech. 27, 393–423.Google Scholar
Mudde, R. F., Groen, J. S. & VanDen Akker, H. E. A. Den Akker, H. E. A. 1997 Liquid velocity field in a bubble column: LDA experiments. Chem. Engng Sci. 52, 4217–4224.Google Scholar
Papailiou, D. & Lykoudis, P. 1968 Magneto-fluid mechanic laminar natural convection: An experiment. Intl J. Heat Mass Transfer 11, 1385–1391.CrossRefGoogle Scholar
Serizawa, A., Kataoka, I. & Michiyshi, I. 1975 Turbulence structure of air–water bubbly flow. Part I. Measuring techniques. Intl J. Multiphase Flow 2, 221–233.CrossRefGoogle Scholar
Sommeria, J. & Moreau, R. 1982 Why, how, and when, MHD turbulence becomes two-dimensional. J. Fluid Mech. 118, 507–518.CrossRefGoogle Scholar
Tagawa, T. & Ozoe, H. 1997 Enhancement of heat transfer rate by application of a static magnetic field during natural convection of liquid metal in a cube. J. Heat Transfer 119, 265–271.Google Scholar
Tagawa, T. & Ozoe, H. 1998 Enhanced heat transfer rate measured for natural convection in liquid gallium in a cubical enclosure under a static magnetic field, J. Heat Transfer 120, 1027–1032.CrossRefGoogle Scholar
Tagawa, T., Authie, G. & Moreau, R. 2002 Buoyant flow in long vertical enclosures in the presence of a strong horizontal magnetic field. Part 1. Fully-established flow. Eur. J. Mech. B/Fluids 21, 383–398.CrossRefGoogle Scholar
Takeda, Y. 1991 Development of an ultrasound velocity profile monitor. Nucl. Engng Design 126, 277–284.Google Scholar
Takeda, Y. & Kikura, H. 2002 Flow mapping of the mercury flow. Exps. Fluids 32, 161–169.Google Scholar
Tokuhiro, A. T. & Lykoudis, P. S. 1994 Natural convection heat transfer from a vertical plate. Part II. With gas injection and transverse magnetic field. Intl J. Heat Mass Transfer 37, 1005–1012.Google Scholar
Wang, T., Wang, J., Ren, F. & Jin, Y. 2003 Application of Doppler ultrasound velocimetry in multiphase flow. Chem. Engng J. 92, 111–122.Google Scholar
Zhang, C., Eckert, S. & Gerbeth, G. 2004 Gas and liquid velocity measurements in bubble chain driven two-phase flow by means of UDV and LDA. In Proc. 5th Intl Conf. Multiphase Flow, Yokohama, ICMF04-260.Google Scholar
Zhang, C., Eckert, S. & Gerbeth, G. 2005 Experimental study of single bubble motion in a liquid metal column exposed to a DC magnetic field. Intl J. Multiphase Flow 31, 824–842.Google Scholar