Large amplitude nonlinear seakeeping using a desingularized method.

Large amplitude ship motion problems are addressed using a non-linear blended time-domain strip theory. The strip theory utilizes body-exact Froude-Krylov and hydrostatic forces with linear diffraction forces. The radiation forces over the bow region are determined via a fully non-linear two-dimensional potential flow solver, while linear added mass and damping terms are used over the remainder of the hull. The two-dimensional potential flow solver uses a desingularized technique to discretize the domain. A new damping mechanism is introduced that modifies the dynamic free surface boundary condition. The new technique allows the solver to remain stable in large amplitude motions as well as free-surface impacting situations. Results are presented for a ship section oscillating in heave, sway, and roll in two dimensions. Additional results are presented for various two dimensional wedges impacting on a free surface. Finally, motions of a high-speed containership in large seas are presented.PhDApplied SciencesOcean engineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/123586/2/3096093.pd