Hostname: page-component-78c5997874-4rdpn Total loading time: 0 Render date: 2024-11-07T21:04:04.675Z Has data issue: false hasContentIssue false

Experimental study of secondary flow in a magnetohydrodynamic channel

Published online by Cambridge University Press:  21 April 2006

S. L. Girshick
Affiliation:
Department of Mechanical Engineering, Stanford University, Stanford. CA 94305, USA Present address: Department of Mechanical Engineering, University of Minnesota, 111 Church Street Southeast, Minneapolis, MN 55455 USA.
C. H. Kruger
Affiliation:
Department of Mechanical Engineering, Stanford University, Stanford. CA 94305, USA

Abstract

The Hall effect in the magnetohydrodynamic (MHD) channel flow of a plasma leads to the presence of transverse Lorentz forces. The non-uniform distribution of these body forces may cause secondary flows to develop; these can exert a significant influence on the plasma momentum, thermal and electrical behaviour. The effect is predicted to be large for envisioned large-scale MHD devices. An experimental study of this phenomenon is described. The apparatus consisted of a laboratory-scale MHD channel in which a controlled net axial current was applied. Plasma velocities were measured using laser-Doppler anemometry. The results demonstrate that transverse Lorentz forces can drive intense secondary flows at a value of the magnetic interaction parameter based on the Hall current of approximately one. The peak measured transverse velocities were 15% of the bulk velocity. Qualitatively, the basic character of the large-scale secondary flow structure was in accord with a simple model based on a first-order distribution of the axial current density. Measurements were also made under a variety of conditions of the profiles of mean axial velocity and of the axial and transverse components of turbulence intensity, of electrode surface temperatures and of plasma voltage distributions. These results all support the conclusion that convective transport by MHD secondary flow caused significant asymmetries to develop in the cross-plane distribution of scalar quantities.

Type
Research Article
Copyright
© 1986 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

Apollonskii, S. M. & Kos'kin Yu. P.1968 On transverse velocity disturbances in magneto-hydrodynamic channel flows. Magnetohydrodynamics 4, 37.Google Scholar
Barton J. P.1980 Fluctuations in combustion driven MHD generators. Ph.D. dissertation; HTGL Report 118, Stanford University.
Bityurin V. A., Zatelepin, V. N. & Lyubimov G. A.1978 Effect of force field nonuniformity on flow in an MHD channel. Fluid Dyn. 13, 1.Google Scholar
Broer L. J. F., Peletier, L. A. & Wijngaarden L. van1960 A mechanical Hall effect Appl. Sci. Res. B, 8, 259.Google Scholar
Demetriades S. T., Maxwell, C. D. & Oliver D. A.1983 Progress in analytical modeling of MHD power generators II. In Proc. 21st Symp. on Engineering Aspects of Magnetohydro-dynamics, Argonne, Illinois.
Demetriades S. T., Oliver D. A., Swean, T. F. & Maxwell C. D.1981 On the magneto-aerothermal instability. AIAA 19th Aerospace Sciences Meeting, St Louis, Paper AIAA-81–0248.Google Scholar
Doss, E. D. & Ahluwalia R. K.1983 Three-dimensional flow development in MHD generators at part load. J. Energy 7, 289.Google Scholar
Fay J. A.1959 Hall effects in a laminar boundary layer of the Hartmann type. Avco-Everett Research Report 81.Google Scholar
Girshick S. L.1985 Secondary flow in a magnetohydrodynamic channel. Ph.D. dissertation, Stanford University.
Girshick, S. L. & Kruger C. H.1983 Evidence of secondary flow in Faraday MHD generators. Proc. 21st Symp. on Engineering Aspects of Magnetohydrodynamics, Argonne, Illinois.
Ishikawa, M. & Umoto J.1984 New approach to calculation of three-dimensional flow in MHD generators. Proc. 22nd Symp. on Engineering Aspects of Magnetohydrodynamics, Starkville, Mississippi.
James, R. K. & Kruger C. H.1983 Joule heating effects in the electrode wall boundary layer of MHD generators AIAA J. 21, 679.Google Scholar
Liu B. L., Lineberry, J. T. & Schmidt H. J.1983 Simplified three-dimensional modeling for MHD DCW channels. J. Energy 7, 456.Google Scholar
Mcclaine A. W., Swallom, D. W. & Kessler R.1985 Experimental investigation of subsonic combustion-driven MHD generator performance. J. Propulsion 1, 263.Google Scholar
Maxwell C. D., Early, D. W. & Demetriades S. T.1985 Predicted strength and influence of MHD-induced secondary flows in recent experiments. Proc. 23rd Symp. on Engineering Aspects of Magnetohydrodynamics, Somerset, Pennsylvania.
Maxwell C. D., Markham D. M., Demetriades, S. T. & Oliver D. A.1977 Coupled electrical and fluid calculations in the cross-plane in linear MHD generators. Proc. 16th Symp. on Engineering Aspects of Magnetohydrodynamics, Pittsburgh.
Melling, A. & Whitelaw J. H.1976 Turbulent flow in a rectangular duct. J. Fluid Mech. 78, 289.Google Scholar
Mitchner, M. & Kruger C. H.1973 Partially Ionized Gases. Wiley.
Reis, J. C. & Kruger C. H.1986 Turbulence suppression in combustion-driven magnetohydro-dynamic channels. J. Fluid Mech. (accepted for publication).Google Scholar
Sastry, V. U. K. & Bhadram C. V. V.1978 Effect of Hall currents on the hydromagnetic flow in an annular channel with a radial magnetic field. Phys. Fluids 21, 857.Google Scholar
Sato H.1961 The Hall effect in the viscous flow of ionized gas between parallel plates under transverse magnetic field. J. Phys. Soc. Japan 16, 1427.Google Scholar
Starr R. F., Christensen L. S., Garrison, G. W. & Whitehead G. L.1982 Preliminary Faraday performance of a large magnetohydrodynamic generator at high magnetic field. J. Energy 6, 163.Google Scholar
Swean T. F., Oliver D. A., Maxwell, C. D. & Demetriades S. T.1981 Prediction of transverse asymmetries in MHD ducts with zero net Hall current. AIAA J. 19, 651.Google Scholar
Tani I.1962 Steady flow of conducting fluids in channels under transverse magnetic fields, with consideration of Hall effect. J. Aerosp. Sci. 29, 297.Google Scholar