Computer analysis and observation of streamer growth at a dielectric interface

A simulation study of streamer growth within a dielectric liquid at a solid interface was undertaken. Using the finite element method with computer graphics, the shape of the growing streamer was determined and plotted. In addition, the changing voltage and electric field values within the dielectric were calculated, and simulated images of these parameters produced. The behavior of the streamer is based on the formation of a localized gas phase discharge and the growth of the resulting plasma within the liquid. The model determines an inception site and predicts a growth path that depends on the electric field immediately surrounding the streamer tip. Two liquids, n-hexane and water, both with an interface, were investigated using the simulation model. The effect of the choice of the liquid and the solid dielectric, in addition to the geometry, was explored. For mixed solid and liquid insulation, the results show that streamer growth depends on the permittivity mismatch between the two materials. Experimental findings are presented that show streamer growth for different interfacial conditions. A good correlation is observed between the theoretical and experimental work.