Flow Electrification in Turbulent Flows of Liquids - Comparison of Two Models for One Specific Case

Abstract

This paper deals with flow electrification phenomenon for turbulent flows of liquids through pipes of a circular cross section. Two models are proposed. The first one is based on the comparison of the radial fluctuant velocity magnitude with the magnitude of the diffuse layer relaxation velocity: it assumes that in the region where the fluctuant velocity is greater than the relaxation velocity the diffuse layer is totally perturbed so that the charge is homogenized by the turbulence, whereas when the relaxation velocity is greater than the fluctuant velocity the diffuse layer is considered not perturbed at all. The charge transported by the flow is then calculated with this new charge profile. The second model consists in solving the system of the diffuse layer equations perturbed by the turbulence, taking into account the eddy diffusivity; then with the profile of the charge obtained in the cross section the charge transported is calculated. Finally, the predictions of the charge transported using each model are compared in a specific case and discussed.