Propulsive motion of cylindrical vibration-driven robot in a viscous fluid

The propulsive motion of a multimass system, vibration-driven robot (VR), in a viscous incompressible fluid was studied. The VR consisted of a round cylindrical body submerged in the fluid and an internal mass (IM) performing small-amplitude pendulum-like oscillations inside the body. Using the method of asymptotic expansions, the combined mechanical and hydrodynamic problems that describe the self-propulsion of the system in the fluid were solved. The hydrodynamic problem was formulated on the basis of the complete non-stationary Navier–Stokes equation. An analytical solution was derived to describe the cruising regime of the VR motion in the fluid. The non-stationary hydrodynamic influence on the VR was determined. The efficiency of the propulsive system’s motion was assessed.