Evolving Computational Capability for Ship Hydrodynamics

Abstract

Abstract : The ability to obtain flow field predictions of surface ships with Reynolds Averaged Navier-Stokes (RANS) codes has improved tremendously in the last few years. This has been a result of improvements in experience, RANS codes in general, and computer capacity. In particular, the move to parallel processing has been a major catalyst for the recent improvements and a threshold of the usefulness of RANS may well have been crossed. This is particularly significant at a time the U. S. Navy is attempting to move to high-speed ships and more operations in the littorals, both of which are driving ship designs well outside of the traditional experience and experimental data bases. A discussion of where RANS computations may be able to significantly influence the current design and analysis process for surface ships is discussed. Specific areas include: hull flow field and resistance, propulsor inflow, waterjet inlets, bilge keel and appendage alignment, roll motions, maneuvering forces, and scale effects. A number of examples are given for various configurations including: Athena fitted with waterjets, AWJ-21, CG-47, DDG-51, an early DD(X) concept, an aircraft carrier, and Sea Shadow.