Estimation of the charge density of a liquid from the surface potential of an insulating container

This paper proposes a method for estimating the charge density of liquid entering insulating containers. The validity of this method is investigated using a computational model which calculates the potential distributions within domains involving insulating containers containing conductive or insulating liquids. The model demonstrates that, for conductive liquids, the charge density can be estimated from the potential outside the containers. As the model can also estimate the liquid potential, it can be used to evaluate the possibility of a spark discharge and its energy. However, the model shows that, for insulating liquids, the method is not suitable for estimating the charge density in the early stages of the filling. Nevertheless, in the steady state, the potential outside the containers approaches that of the liquid surface at the centre of the containers.