Title :
Stability of a DC SF6 arc in an axially accelerating flow
Author :
Blundell, R.E. ; Fang, Michael T C ; Vourdas, A.
Author_Institution :
Dept. of Electr. Eng. & Electron., Liverpool Univ., UK
fDate :
10/1/1997 12:00:00 AM
Abstract :
The stability of a DC arc burning in an axially accelerating flow of SF6 is investigated. The method of normal modes is applied to the equations governing an axisymmetric, infinitesimal perturbation of a self-similar arc, and solutions are obtained numerically. Results are presented for a range of discharge conditions. The physical mechanisms causing instability are deduced from equations for the time-averaged, squared enthalpy, and velocity of a perturbation. The steep radial gradient of the density at the edge of the arc is shown to cause instability. The effect of density fluctuations in comparison with velocity fluctuations is not negligible, and the possible implication of this result for turbulent arc modeling is discussed
Keywords :
arcs (electric); plasma density; plasma devices; plasma flow; plasma fluctuations; plasma instability; plasma thermodynamics; plasma turbulence; sulphur compounds; DC arc burning; SF6; SF6 arc; axially accelerating flow; axisymmetric infinitesimal perturbation; density; density fluctuations; discharge conditions; instability; normal modes; perturbation velocity; physical mechanisms; self-similar arc; stability; steep radial gradient; time-averaged, squared enthalpy; turbulent arc modeling; velocity fluctuations; Acceleration; Circuit breakers; Circuit stability; Fluctuations; Heat engines; Nonlinear equations; Plasma devices; Plasma stability; Predictive models; Stability analysis;
Journal_Title :
Plasma Science, IEEE Transactions on
