Numerical investigation of cylinders’ motion trajectory and landing positions in regular waves

Abstract

During the underwater motion of structures, random effect of waves and currents can lead to sudden changes in its hydrodynamic characteristics, the sudden changes in hydrodynamic characteristics and random effect of currents can further couple, seriously affecting its underwater motion mode affecting, so a targets' underwater motion situation model (TUMS) was proposed in this paper which can predict the targets' underwater motion trajectory envelope and the landing positions. Firstly, the influence of random factors such as wave, current, drag coefficient, and xt coefficient was considered based on the targets' three-dimensional (3-D) motion theory and a TUMS model was proposed. Secondly, the underwater motion trajectory of the cylinder is simulated using the TUMS model, and the numerical simulation results are compared with the experimental results which were in good agreement with experimental results. Thirdly, the effect of wave height and wave frequency on the cylinders' motion trajectory was discussed. Finally, the cylinders’ underwater motion trajectory envelope, landing position distribution, sinking bottom velocity distribution, and sinking bottom attitude distribution were calculated.