Locomotion of Self-Excited Vibrating and Rotating Objects in Granular Environments

Many reptiles, known as ‘sand swimmers’, adapt to their specific environments by vibrating or rotating body. To understand these type of interactions active objects with granular media, we study a simplified model self-excited spherical object (SO) immersed in the bed, using three-dimensional discrete element method (DEM) simulations. Modelling vibration an oscillatory motion, simulate longitudinal locomotion SO three modes: transverse vibration, rotation around different axes, and combination both. We find that mode oscillation y direction coupled x-axis is optimal sense rises fastest, periodic oscillations, z while remaining stable at initial x position. analyze physical mechanisms governing meandering up down show large oscillations are caused asynchronous changes between directions rotation. also observed SO’s rising rate sensitive parameters: amplitude, frequency, f, angular velocity, Ω. report following results. 1. When frequencies motion synchronised, when Ω<0 sinks Ω>0; average rising/sinking proportional |Ω|. 2. The increases linearly amplitude. 3. There exists critical above below which different. Our reveals range parameters idealized ‘swimmers’ need use optimize performance environments.