The Kinematic Characteristics of Submerged body under the Influence of the South China Sea Marine Environment

Abstract Based on real ocean environmental data provided by HYCOM, this paper establishes theoretical force model and three-degree-of-freedom kinematic model for the submerged body under the influence of the South China Sea marine environment by combining dynamic equations with the Morison empirical formula. It analyzes the motion of the submerged body under typical sea conditions and reveals its kinematic characteristics under marine environmental influences. The results show that in the horizontal plane, ocean currents play a dominant role in the body’s motion, exhibiting a characteristic of “drifting with the current,” meaning the body’s direction of motion generally aligns with the current direction. Vertically, the ocean currents and seawater density vary at different depths. The motion of the submerged body in the vertical direction exhibits oscillatory behavior, particularly near the pycnocline, where the amplitude of oscillation is most pronounced, reaching up to ±10 meters.