Simulation of Microbubbles during the Initial Stages of Breakdown in Cyclohexane
2013 (English)In: 2013 Annual Report Conference on Electrical Insulation and Dielectric Phenomena, IEEE conference proceedings, 2013, 901-904 p.Conference paper (Refereed)
The formation of a vapor microbubble has previouslybeen suggested to be the initial mechanism in the process ofdielectric failure of dielectric liquids. The bubble is generated bya rapid, highly localized heating of a volume close to a highlystressed electrode, caused by electric currents in the liquid athigh voltages. A numerical model is presented in order toinvestigate the dynamics of a single microbubble in the pointplanegeometry in cyclohexane. A condition for the formation ofa vapor bubble is discussed. Thereafter, a Computational FluidDynamics (CFD) model of two-phase flow with phase transition isused to study the dynamics of the bubble from generation tocollapse, under a highly divergent electrostatic field in asubcooled liquid. The amount of subcooling in the simulations is5 K, and it is found that convergence gets significantly weaker asthe amount of subcooling increases. The bubble dynamics is alsosimulated considering the electrohydrodynamic (EHD) processesin the liquid and vapor phases. Finally, it is shown how theelectrostatic forces on the dielectric will cause a bubble to detachfrom the electrode.
Place, publisher, year, edition, pages
IEEE conference proceedings, 2013. 901-904 p.
Bubble, breakdown, cyclohexane
Other Electrical Engineering, Electronic Engineering, Information Engineering
Research subject SRA - Energy
IdentifiersURN: urn:nbn:se:kth:diva-139057ScopusID: 2-s2.0-84901743769OAI: oai:DiVA.org:kth-139057DiVA: diva2:683017
Conference on Electrical Insulation and Dielectric Phenomena CEIDP October 2013,Shenzhen (China)
QC 201401102014-01-012014-01-012014-01-10Bibliographically approved