Ability to predict the added resistance of ships in waves has matured

Over the last five years the RAW working groups in CRS have investigated the nature of the added resistance of ships at sea and the merits of alternative ways to predict its magnitude.
The investigation made use of MARIN’s potential flow Rankine source code FATIMA, and CFD contributions from DNV GL, Lloyd’s Register, ABS, Bureau Veritas, Chantiers de ‘l Atlantique, Navantia and MARIN. CETENA examined the impact of course-keeping. These numerical results were compared with scale model tests at MARIN and DGA. In the first years, the work focused on the added resistance of a container ship, a full block tanker and a fast, naval hull in waves from four directions. We learned that the added resistance is not always described adequately in terms of a quadratic transfer function, and the work in later years has focused on deviations from this concept.