Executive Summary : | This research project aims to explore the dynamics of granular chains, translating/rotating/oscillating objects in a granular medium. Four objectives are identified: understanding how an active or passive chain diffuses in a sea of spherical particles or shape heterogeneous mixtures, comparing active chain dynamics with biological polymer dynamics, and determining the extent of diffusion affected by environmental concentration. The study also investigates the lift force in a translating and rotating disk in a granular medium, its magnitude when changing the spin axis of a spherical intruder, and the pressure distribution and shear rate across the sphere. The study also investigates the influence of material properties on lift force magnitude. The study also examines the behavior of non-spherical intruders oscillated in a granular medium, such as sandfish, which exhibit an in-plane meandering motion with a frequency of about 3 Hz and an amplitude of about half its body length. The minimal work required to move the object in a sinusoidal path at 3 Hz frequency is observed for other intruder shapes, and the addition of a limb-like structure to the passive object (cylinder) may affect the observed dynamics. In conclusion, this research aims to provide insights into the dynamics of granular chains, translating/rotating/oscillating objects, and the behavior of animals native to desert environments. |