Hydro Dynamic Model of Dielectric Breakdown
When dielectric liquid is subjected to charge carriers, space charge is produced giving rise to coulomb’s force. The charge carriers are originated from electrode surfaces. The hydraulic instability is produced due to which convicting currents are initiated.
Thus whenever conduction in a fluid is subjected to space chargers, convection motion is likely to occur.
To observe this phenomenon, two parallel plate electrodes immersed in oil and current is injected i.e. charge carriers are injected this causes space charge. The hydraulic instability is observed at a critical value of voltage.
If voltage across electrodes is further increased, turbulent effect is observed in oil. At a voltage near to breakdown voltage the speed of liquid motion is approximated to √∈/ρ / E where ε is permittivity of liquid, ρ is specific mass and E is electric field strength.