Hostname: page-component-8448b6f56d-c4f8m Total loading time: 0 Render date: 2024-04-24T18:50:03.177Z Has data issue: false hasContentIssue false

Resistive tearing-mode instability in a magnetic-field-reversing current sheet with coplanar viscous stagnation-point flow

Published online by Cambridge University Press:  13 March 2009

Justin T. C. Ip
Affiliation:
Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire, 03755, U.S.A.
Bengt U. Ö. Sonnerup
Affiliation:
Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire, 03755, U.S.A.

Abstract

The tearing-mode instability of a magnetic-field-reversing current sheet in the presence of coplanar incompressible stagnation-point flow is examined. The unperturbed equilibrium state is an exact solution of the steady-state, dissipative, incompressible magnetohydrodynamic equations; thus the analysis is valid even for small viscous and resistive Lundquist numbers Sν and Sη. The instability problem has no known analytical solution; for this reason, it is studied numerically by use of a finite-element method. Simulation results indicate stability for sufficiently small values of Sν or Sη and instability for large values. The boundary separating stable and unstable regions in the (Sν, Sη) plane is located. In the unstable regime, the simulation results show formation and subsequent convection of magnetic islands along the current sheet at about 80% of the unperturbed outflow flow speed, on average. Stretching and pinching of convecting magnetic islands are also observed. The results show the occurrence of multiple X-line reconnection at the centre of the current sheet (x = 0). Small-scale structures of vorticity and current density near the X-point reconnection sites are found to be qualitatively consistent with results obtained by Matthaeus. Normalized global linear growth rates are found to obey the approximate power law, within the ranges 20 ≦ Sν ≦ 70 and 200 ≦ Sη 1000. At least for Sν ≦ 1000, the number of magnetic islands is found to be nearly independent of Sν indicating the existence of a narrow band of dominant wavelengths in this range. The stretching of magnetic islands, which is present in this coplanar flow and field configuration, but not in the perpendicular flow and field configuration examined by Phan and Sonnerup, causes a substantial decrease in linear growth rate relative to that obtained by those authors. The stability curves obtained are qualitatively similar in both analyses, but the stable region is much larger for coplanar flow and field. Unlike most simulations of the tearing mode, no symmetry conditions are imposed on the perturbations; nevertheless, they develop in a symmetric manner.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1996

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

Anderson, C. & Priest, E. R. 1993 J. Geophys. Res., 98, 19 395.Google Scholar
Bondeson, A. & Persson, M. 1986 Phys. Fluids 29, 2997.CrossRefGoogle Scholar
Bulanov, S. V., Syrovatskiiˇ, S. I. & Sakai, J. 1978 JETP Lett. 28, 177.Google Scholar
Chen, X. L. & Morrison, P. J. 1990 Phys. Fluids B 2, 495.CrossRefGoogle Scholar
Clark, A. 1964 Phys. Fluids 7, 1299.CrossRefGoogle Scholar
Clark, A. 1965 Phys. Fluids 8, 644.CrossRefGoogle Scholar
Einaudi, G. & Rubini, F. 1986 Phys. Fluids 29, 2563.CrossRefGoogle Scholar
Einaudi, G. & Rubini, F. 1989 Phys. Fluids B 1, 2224.CrossRefGoogle Scholar
Fu, Z. F. & Lee, L. C. 1986 J. Geophys. Res. 91, 13 373.CrossRefGoogle Scholar
Furth, H. P., Killeen, J. & Rosenbluth, M. N. 1963 Phys. Fluids 6, 459.CrossRefGoogle Scholar
Gresho, P. M. 1991 a Annu. Rev. Fluid Mech. 23, 413.CrossRefGoogle Scholar
Gresho, P. M. 1991b Comput. Meth. Appl. Mech. Engng 87, 201.CrossRefGoogle Scholar
Gresho, P. M. 1991 c. Adv. Appl. Mech. 28, 45.CrossRefGoogle Scholar
Gunzburger, M. D. 1989 Finite Element Methods for Viscous Incompressible Flows: A Guide to Theory, Practice, and Algorithms, p. 209.Google Scholar
Gunzburger, M. D., Meir, A. J. & Peterson, J. S. 1991 Math. Comput. 56, 523.CrossRefGoogle Scholar
Ip, J. T. C. 1993 Finite element simulation of two-dimensional incompressible magnetohydrodynamic flows. PhD dissertation, Thayer School of Engineering, Dartmouth College.Google Scholar
Jardine, M., Allen, H. R., Grundy, R. E. & Priest, E. R. 1992 J. Geophys. Res. 97, 4199.CrossRefGoogle Scholar
Jardine, M., Allen, H. R. & Grundy, R. E. 1993 J. Geophys. Res. 98, 19 409.Google Scholar
Johnsen, M., Paulson, K. D. & Werner, F. E. 1991 Int. J. Numer. Meth. Fluids 12, 765.CrossRefGoogle Scholar
Killeen, J. & Shestakov, A. I. 1978 Phys. Fluids 21, 1746.CrossRefGoogle Scholar
Lee, L. C. & Fu, Z. F. 1986 J. Geophys. Res. 91, 3311.CrossRefGoogle Scholar
Levitt, L. C. 1963 J. Math. Anal. Applics 6, 483.CrossRefGoogle Scholar
Lin, C. C. 1958 Arch. Rat. Mech. Anal. 1, 391.CrossRefGoogle Scholar
Matthaeus, W. H. 1982 Geophys. Res. Lett. 9, 660.CrossRefGoogle Scholar
Papanastasiou, T. C., Malamataris, N. & Ellwood, K. 1992 Int. J. Numer. Meth. Fluids 14, 587.CrossRefGoogle Scholar
Parker, E. N. 1973 J. Plasma Phys. 9, 49.CrossRefGoogle Scholar
Peterson, J. S. 1988 Numer. Meth. Partial. Diff. Eqns 4, 57.CrossRefGoogle Scholar
Phan, T. D. & Sonnerup, B. U. Ö. 1990 J. Plasma Phys. 44, 525.CrossRefGoogle Scholar
Phan, T. D. & Sonnerup, B. U. Ö. 1991 J. Plasma Phys. 46, 407.CrossRefGoogle Scholar
Press, W. H., Flannery, B. P.Teukolsky, S. A. & Vetterling, W. T. 1986 Numerical Recipes: The Art of Scientific Computing, p. 504. Cambridge University Press.Google Scholar
Rutherford, P. H. 1973 Phys. Fluids 16, 1903.CrossRefGoogle Scholar
Ramshaw, J. D. & Mesina, G. L. 1990 Comput. Fluids 20. 907.Google Scholar
Sonnerup, B. U. Ö. & Priest, E. R. 1975 J. Plasma Phys. 14, 283.CrossRefGoogle Scholar
Sonnerup, B. U. Ö. & Sakai, J. I. 1981 EOS Abstract 62, 353.Google Scholar
Sonnerup, B. U. Ö., Ip, J. & Phan, T. D. 1990 Physics of Magnetic Flux Ropes (ed. Russell, C. T., Priest, E. R. & Lee, L. C.), p. 63. AGU Monograph, Washington, DC.CrossRefGoogle Scholar