Flow electrification process: the physicochemical corroding model revisited

Though the phenomenon of flow electrification has been observed for several decades, the physicochemical process appearing at the solid/liquid interface creating the double layer is not yet totally understood. In particular, returns from experiments made with oil and pressboard seems to show that the wall current density at the interface for a diffuse layer under development is not only a function of the chemical behaviour of the interface but also of the flow wall shearing stress. The present work concerns analysis of experiments made with heptane flows through a stainless steel capillary of varying length. In that case also, even if the wall material is conductive and not porous, divergences appear with the classical physicochemical model predictions, while a model taking into account the effect of the wall shearing stress on the interfacial process seems to have a much better agreement with the experiments, especially, for high laminar Reynolds numbers.