Experiments and modeling of an instability of an atmospheric pressure arc

An instability of a free-burning atmospheric pressure ≈200 A carbon arc is investigated experimentally and modeled analytically. The presence of the instability is found to depend critically on cathode dimensions. In particular, for cylindrical cathodes, the instability occurs only for a narrow range of cathode diameters. Cathode spot motion is proposed as the mechanism of the instability. A simple fluid model combining the effect of the cathode spot motion and the inertia of the cathode jet successfully describes the shape of the arc column during low amplitude instability. The amplitude of cathode spot motion required by the model is in agreement with measurements. The average jet velocity required is approximately equal to that found from applied oscillating transverse magnetic field experiments. The primary reasons for cathode spot motion are most likely cathode vaporization and interaction of arc current with the current distribution in the cathode. Cathode surface temperature distribution is likely ...

[1]  S. Zweben,et al.  Experiment and Modeling of Atmospheric Pressure Arc in Applied Oscillating Magnetic Field , 2000 .

[2]  A. Vourdas,et al.  Stability of a DC SF/sub 6/ arc in an axially accelerating flow , 1997 .

[3]  Xiaogang Wang,et al.  An electrostatic magnetohydrodynamics theory for resistive-viscous helical instabilities of arc discharges , 1997 .

[4]  Thomas L. Ochs,et al.  Chaotic responses in electric arc furnaces , 1994 .

[5]  P. Bellan,et al.  Magnetic suppression of arc blowout in a model arc furnace , 1992 .

[6]  John J. Lowke,et al.  Theory of free-burning arc columns including the influence of the cathode , 1992 .

[7]  G. Jones.  High pressure arcs in industrial devices : diagnostic and monitoring techniques , 1988 .

[8]  H. Hülsmann,et al.  The helical magnetic instability of arcs in an axial magnetic field treated by a linear time dependent perturbation theory , 1987 .

[9]  H. Hülsmann,et al.  Experimental investigation of the helical magnetic instability of an arc discharge in an axial magnetic field and comparison with theory , 1987 .

[10]  John Lancaster,et al.  The Physics of Welding , 1984 .

[11]  E. Hantzsche.  Thermal Runaway Prevention in Arc Spots , 1983, IEEE Transactions on Plasma Science.

[12]  J. Szekely,et al.  A mathematical model of the cathode region of a high intensity carbon arc , 1983 .

[13]  James M. Lafferty,et al.  Vacuum arcs : theory and application , 1980 .

[14]  Peter Plaschko,et al.  Helical instabilities of slowly divergent jets , 1979, Journal of Fluid Mechanics.

[15]  J. Mentel.  The influence of vaporization upon the roots of a high current arc. II , 1977 .

[16]  A. M. Howatson,et al.  The instability of electric arcs burning axially in accelerated flow , 1976 .

[17]  K. Ragaller,et al.  Investigations on Instabilities of Electric Arcs , 1974 .

[18]  N. A. Krall,et al.  Principles of Plasma Physics , 1973 .

[19]  J. Mentel,et al.  Der Einsatz der Wendelinstabilität in wandstabilisierten Lichtbögen , 1973 .

[20]  S. Ferrara,et al.  Conformal Algebra in Space-Time and Operator Product Expansion , 1973 .

[21]  P. Gaede.  Der wendelnde Wasserstoffbogen , 1972 .

[22]  S. Crow,et al.  Orderly structure in jet turbulence , 1971, Journal of Fluid Mechanics.

[23]  C. H. Sharp,et al.  The effect of cathode geometry on the stability of arcs , 1969 .

[24]  Charles L. Mantell,et al.  Carbon and Graphite Handbook , 1968 .

[25]  G. Eoker.  Electrode components of the arc discharge , 1961 .

[26]  N. Rasor,et al.  Thermal properties of graphite, molybdenum and tantalum to their destruction temperatures , 1960 .

[27]  P. Guillery.  Notizen: Über Temperatur und Stromdichte an der Kathode von Hochstromkohlebögen , 1955 .

[28]  H. Maecker,et al.  Plasmaströmungen in Lichtbögen infolge eigenmagnetischer Kompression , 1955 .