COMPARISON OF FORCE AND MOTION PREDICTIONS USING STRIP THEORY AND A THREE-DIMENSIONAL METHOD FOR HULLS AT ZERO SPEED IN WAVES

Abstract : A comparison is presented of ship added mass, damping, exciting force, and motion coefficients calculated by Program SMP which uses strip theory and Program MOTIONSO which uses a three-dimensional singularity method. The comparison is made for four ship hulls at zero speed in waves. A summary is given of similarities and differences between the two methods. For the vertical modes of motion: surge, heave, and pitch, the comparison between the two methods generally shows the expected trend of poor agreement at lower frequencies and better agreement at higher frequencies. For the lateral modes of motion: sway, roll, and yaw, the agreement is more dependent upon the shape of the hull and the density and distribution of points used by MOTIONSO to represent the hull. Comparison of calculated and measured motions for one ship hull shows that the agreement is fair. (Author)