Discussing the rotation movement of an electric whirl through mechanical modelling and video analysis

Abstract

This paper performs a semi-quantitative and low-cost experiment, combining video analysis technique and mechanical modelling, to discuss the rotation movement of an electric whirl on the top of a well-known and popular electrostatic generator. To this end, we perform video analysis of the circular trajectory described by a given sharp point of the electric whirl arm. We propose a simple model to describe the inertia moment of the electric whirl in terms of simple geometries, like: cylinders, truncated cone, and one-dimensional linear arms. The analytical results for the inertia moment are validated using SolidWorks simulations and the electronic microscopy experimental technique. When considering a simple electrostatic model for the electric field around sharp points of the electric whirl arms, kinematic and dynamic analyses are used to estimate an upper bound for the magnitude of the electric charge pulled from the air, which results in the electric wind phenomenon.