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Published on: August 18, 2018
Dynamical mechanism of the liquid film motor
Zhong-Qiang Liu1, Ying-Jun Li, Guang-Cai Zhang
1State Key Laboratory for GeoMechanics and Deep Underground Engineering, SMCE, China University of Mining and Technology, Beijing 100083, China.
Abstract:
The paper presents a simple dynamical model to systemically explain the rotation mechanism of the liquid film motor reported by experiments. The field-induced-plasticity effect of the liquid film is introduced into our model, in which the liquid film in crossed electric fields is considered as a Bingham plastic fluid with equivalent electric dipole moment. Several analytic results involving the torque of rotation, the scaling relation of the threshold fields, and the dynamics equation of a square film and its solution are obtained. We find that the rotation of the liquid film motor originates from the continuous competition between the destruction and the reestablishment of the polarization equilibrium maintained by the external electric field, which is free from the boundary effects. Most experimental phenomena observed in direct current electric fields are interpreted well.
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