Numerical simulation on planar motion mechanism of KCS ship model with a body-force propeller model

In order to solve the ship maneuvering hydrodynamic derivatives efficiently and accurately, full-appendage KCS ship model is taken in this paper as the studying object. Based on RANS equation and VOF model, a descriptive body-force model is established to represent real propellers on the star-ccm+; the influences of the free surface wave and motion attitudes change on hydrodynamic are taken into account. The oblique motion, the yaw motion, the combination of yaw and drift angle motion on Planar Motion Mechanism (PMM) are simulated, and the athwartship force Y, the yawing moment N, and the heeling moment K are also acquired. The simulation results are then compared with the actual test results: according to the dynamics equation of PMM test, the time history curves of numerical and experimental results are analyzed with least-squares fitting and Fourier integral, where the hydrodynamic derivatives of manipulation are finally obtained. The results demonstrate the feasibility of the proposed method in PMM simulation, though the errors of Y'vvv and N'vvv are slightly larger, the errors of remaining hydrodynamic derivatives are all below 15%.