Underwater Motion Analysis of Thin Discs with Non-uniform Mass Distribution

Abstract

Unlike the streamlined structure of existing underwater gliders, the disc structure can glide in all directions by controlling its center of gravity and buoyancy center, and it is expected to use it to design a new underwater gliding robot. By changing the position relationship between the center of gravity-buoyancy center and the center of gravity-point buoyancy, this paper simulates the falling and rising motion of thin disks, and derives the quasi-steady-state equations for falling and rising of thin disks. Studies have shown that a smaller center of gravity—buoyancy center offset $$e$$ and center of gravity—point buoyancy offset $$\delta$$ can result in a large net horizontal displacement of a thin disk. In this paper, the least squares method fitting of the offset is further performed, indicating that when the offsets $$e$$ and $$\delta$$ change within a certain range, the net horizontal displacement is positively correlated with $$e$$ and $$\delta$$ respectively. The analysis conclusions of this paper have certain guiding significance for the design of thin disc underwater gliders in the future.