Simulation of surface ship dynamics

We present a summary of the three-year Challenge Project (C68), begun in 2001, with the objective of demonstrating a capability to simulate time-dependent six-degree-of-freedom motions of ships in waves and the associated near-field flow using unsteady Reynolds-Averaged Navier-Stokes (RANS) codes. The efforts involved a team of researchers using two state-of-the-art unsteady RANS codes for a progression of building-block simulations at both model- and full-scales and for practical configurations including detailed resolution of propulsors and appendages. The two RANS codes used for this project are UNCLE, developed at the Mississippi State University, and CFDSHIP-IOWA, developed at the University of Iowa. The three-year efforts have successfully demonstrated a capability to simulate coupled pitch/heave motions, coupled pitch/heave/roll motions, maneuvers in the horizontal plane, and near-field wake, including propeller and viscous effects. The predictive capability demonstrated in this project has clearly paved the way for more challenging computations that involve large-amplitude motions in high sea states for a new generation of naval ships, including surface combatant and other future hull forms.