A drift/diffusion conduction model for flow electrification of turbulent liquid dielectrics

A drift/diffusion flow electrification model is developed for bipolar conduction in a turbulent liquid dielectric between rotating concentric cylindrical electrodes with open-circuited, short-circuited, or DC voltage energized electrodes. Experimental data are used to estimate model parameters such as the density of each charge carrier at the electrode walls and the mobility ratio of the charge carriers. Typical experimental measurements indicate wall charge densities much larger than the equilibrium charge densities of each carrier, invalidating a quasiequilibrium ohmic conductivity model as the local conductivity near the wall is enhanced over the equilibrium conductivity. Specific electrode wall charge densities are found which yield near self-consistent solutions with measurements of open-circuit voltage, short-circuit current, and turbulent core charge densities. Experimental DC voltage excitation across the cylinders is treated in anticipation of future measurements.<>