The role of dielectrophoresis in the water treeing phenomenon

The water treeing phenomenon is considered from the viewpoint of how far dielectrophoresis can be the decisive phenomenon. In the model concept discussed, a locally increased electric field leads to a local increase of the concentration of water molecules. The consequent precipitation of liquid water produces water trees. A quantitative examination of the electric forces on molecular dipoles shows that, taking into account only the net flow of molecules, there is a much higher force on these dipoles than expected from previous model concepts. Consideration of the diffusion processes through curved boundaries shows that there is an additional factor in increasing the local concentration of molecules. The results of numerical computations show that for diffusion processes, only slight deviations from symmetry may lead to significant changes in the local concentrations of molecules. Computations of the electric field distribution around water trees (simulated by ellipsoids of rotation) indicate the directions of the movement of water molecules and show that the lines of constant electric field resemble the shape of the water trees