A Vibratory Conveying Method for Planetary Regolith: Preliminary Experiment and Numerical Simulation
Planetary regolith conveying is an important process during planetary in situ resource utilization. After introducing finlike asperities on a longitudinally vibrated trough surface, we experimentally investigated the effects of vibration amplitude, frequency, and trough inclination angle on the particle flow state and directional conveying capacity. A numerical simulation based on the discrete element method (DEM) was then employed to study the detailed particle motion. Three flow states gradually appeared as the vibration strength increased: the particles remain stationary, flow down to the bottom of the trough, or directionally convey toward the discharge hole. The results indicated that the directional conveying capacity increased and decreased monotonically with increases in the vibration amplitude and trough inclination angle, respectively. The conveying capacity changed circuitously as the frequency increased and vanished when the frequency approached the resonant frequency of the trough. Additionally, according to the DEM simulation, breaking the force chains in the particle pile is necessary for conveying. The asymmetric force induced by the finlike asperities and its cumulative effect over time determines the particle flow state and conveying capacity. The particle flow velocity decreased as the granular layer height increased. This paper provides inspiration and guidance for designing a new type of conveyor for planetary regolith.
Keywords: Vibrations, Moon, Finite element analysis, Discharges (electric), Surface treatment, Surface texture, Resonant frequency