Research Projects

Desert-native animals have evolved to walk on the surface or exhibit subsurface motion with minimal energy loss, such as sand lizards and sidewinder snakes. This understanding has various applications, including designing robots for rescue operations, mining operations, and understanding the dynamics of subsurface motion in earth sciences, biology, and engineering. Preliminary numerical simulation results show that when a passive object is wiggled horizontally, it can rise, sink, or stay at the same position in a granular medium depending on the amplitude and time period of wiggling. A mathematical model inspired by nature and experimental studies is proposed to better understand the rise or sink dynamics. A cavity is created at both ends of an intruder's direction of motion when it oscillates horizontally within a granular medium. For an intruder to move upward, a layer of particles must settle at the bottom of the cavity, allowing it to climb upon the bed of particles and rise within the medium. The downward sink occurs when the intruder oscillates at a lower time period and generates an optimal force to fluidize the particles beneath it. The objectives of the proposed project include developing a mathematical model and computing coarse-grained flow fields to explain the rise or sink of non-spherical intruders in a 2D system, performing numerical simulations and computing the coarse-grained flow fields for the wiggling motion of sandfish-like shapes in a 2D and 3D system, and extending the mathematical model to other objects.