Streamer breakdown in elongated, compressed and tilted bubbles immersed in water

In this paper we report on results from a computational investigation of a streamer evolution in distorted bubbles immersed in water. Electric field inside highly distorted bubbles can be essentially enhanced or depleted relative to the field in a spherical bubble. We show that elongation or compression of a bubble is crucial for a streamer formation. In bubbles elongated along the external electric field a streamer breakdown occurs at higher values of the field than in spherical bubbles. In compressed bubbles the external field required for a streamer ignition can be as low as 15–20 kV cm−1 despite the shorter avalanche path. The streamer ignition field is estimated for different bubbles aspect ratio b/a.