Numerical study of particle transport by an alternating travelling-wave electrostatic field

Abstract

Precise particle control is crucial to the development of In Situ Resource Utilization (ISRU) devices on the Moon and Mars. The electrostatic method becomes a promising particle control method for the high-vacuum and low-gravity extraterrestrial conditions. In this paper, the dynamics of particle transport by an alternating four-phase travelling-wave electrostatic field is numerically investigated. The discrete element method (DEM) is used for modeling particles' behaviors, and the distribution of electric field is simulated by the finite element method (FEM). The electrostatic force is exerted on each particle at a mesoscopic level and the interaction forces between particles are carefully included. The simulation is validated with existing experimental results, the detailed particle trajectories and macroscopic phenomena, such as particle ensemble transport mode, transport direction and leap heights, are explained by the force analysis in the simulation. The results show that particle transport direction is independent of particle charge polarities. Particle transport velocity and the changes of electrodes’ polarities should be designed in conjunction with each other for particle directed transport. Comparing with the particle forward transport for low excitation frequency, the backward transport of particle under higher frequency conditions could be adopted to realize much faster and more smooth particle directed transport.