Influence of Microscopic Morphological Disturbance on the Streamer Interface Stability in Liquid Dielectrics

This paper deals with the influence of microscopic morphological disturbances on the surface stability of streamer developing in a dielectric liquid. A dynamic model based on the stresses acting at the streamer channel surface is established, and the influence of different modes of microscopic morphological disturbances on the surface stability of streamer are analyzed. The model shows that disturbances on the streamer body can cause pinch-off when the applied voltage is low. At higher voltage, the short-wavelength disturbance is easier to cause unstable of streamer, such as branching, shrinkage, expansion and pinch-off, than long-wavelength disturbance. The symmetric disturbance grows faster than asymmetric disturbance. The streamer head is also sensitive to disturbances and becomes unstable. Depending on the form of the disturbance, the perturbation on streamer head may cause streamer branching and direction change.