Abstract:When navigating near surface, underwater vehicle will cause inertial motion of the fluid in the surrounding flow field, and the kinetic energy, meanwhile, will be dissipated with the wave diffusion. It can be described by added mass and damping coefficient how water effects the natural period and amplitude attenuation velocity of the near surface vehicle. In this paper, the computational fluid dynamics software STAR-CCM+ is used to carry out the numerical simulation of free rollling and pitching attenuation motion of the near surface vehicle. According to the free attenuation time history curves obtained under different initial motion amplitudes, the added mass and damping coefficient of the roll and pitch can be calculated respectively. Combined with the actual motion, the causes of the changes of the additional mass and damping coefficient under different initial motion amplitudes are analyzed respectively.
