Thermal bubble breakdown in liquid nitrogen under nonuniform fields

Author

Hara, Masanori ; Wang, Zhen-chao ; Saito, Hirokatsu

Author_Institution

Fac. of Eng., Kyushu Univ., Fukuoka, Japan

Volume

1

Issue

4

fYear

1994

fDate

8/1/1994 12:00:00 AM

Firstpage

709

Lastpage

715

Abstract

The electrical forces acting on thermally induced bubbles in nonuniform field gaps with/without fins and the correlation between bubble behavior and dielectric characteristics in liquid nitrogen are studied. The results show that the gradient force and Maxwell stress strongly affect the bubble dynamics and bubble shape in the gap. Especially the pronounced gradient force near the fin tip reduces the growth of bubble there. These electrical forces acting on the bubble result in a lesser effect of thermal bubble on the breakdown voltage if the fins are formed to guide a bubble trapped in the groove from a higher field region to a lower one

Keywords

bubbles; cryogenics; electric breakdown of liquids; nitrogen; Maxwell stress; breakdown voltage; bubble behavior; cryogenic liquids; dielectric characteristics; fin tip; gradient force; liquid nitrogen; nonuniform field gaps; thermal bubble breakdown; thermally induced bubbles; Conductors; Cryogenics; Dielectric liquids; Electric breakdown; Electrodes; Nitrogen; Superconducting coils; Surface finishing; Surface treatment; Voltage;

fLanguage

English

Journal_Title

Dielectrics and Electrical Insulation, IEEE Transactions on

Publisher

ieee

ISSN

1070-9878

Type

jour

DOI

10.1109/94.311714

Filename

311714