PhD student Jannis Teunissen from Centrum Wiskunde & Informatica (CWI) has made major progress in modelling the early stages of electric discharges as they occur in lightning, high voltage electricity nets and plasma technology. He received a 'cum laude' predicate for his thesis '3D Simulations and Analysis of Pulsed Discharges', which he defended on 12 November 2015 at Eindhoven University of Technology. Teunissen has developed computer models that allow for studying their development in full three dimensions within hours, while up to now one had to wait weeks or months, or in many cases computations were not possible at all.
While electrical engineers and lightning researchers typically assume that discharges would always grow in the direction of the electric forces, experiments in Eindhoven and Japan have shown, that they sometimes can move just into a perpendicular direction. Teunissen’s simulations explained these apparently paradoxical observations: a typical discharge needs both electrons and a high electric field. Under certain conditions the discharge grows rather into the direction where free electrons are available than where the field is high. But to see such behavior, a fully three-dimensional simulation is needed.
Jannis Teunissen performed his PhD research in the Multiscale Dynamics research group at CWI, which is headed by Ute Ebert. In October 2015 he won the Student Award of Excellence at the Gaseous Electronics Conference in the USA. The PhD research has been funded by Technology Foundation STW (project 10755).
More information: the MD research group at CWI, www.cwi.nl/research-groups/Multiscale-Dynamics and www.cwimd.nl. Promotor is prof. dr. Ute Ebert (CWI and TU/e) and co-promotor dr. ir. Sander Nijdam (TU/e).
Animation of two interacting streamers in three dimensions. Left: electron density, right: electric field strength. Animation by Jannis Teunissen, CWI.