G.J. Grigoropoulos, G. M. Katsaounis
MEASURING PROCEDURES FOR SEAKEEPING TESTS OF LARGE-SCALED SHIP MODELS AT SEA
This paper describes the procedures developed in the Laboratory for Ship and Marine Hydrodynamics (LSMH) of NTUA to test large models of ships at sea. It is common practice in experimental ship hydrodynamics to test scaled ship models in Towing Tank facilities, to investigate their performance in calm water and in waves. However, it is both time-consuming and very expensive to generate conditions, which simulate properly the actual sea environment. Parameters of the environment such as the incident wave angle, the short-crested nature of the waves encountered in real world, the effect of the wind and the scale of the experiment, which should be accommodated in the available facility, reduce, or even prohibit in some cases, the execution of such tests.
An alternative to laboratory measurements is to conduct tests with larger models at sea and to record both the sea conditions and the ship performance. This paper describes the design, specification, instrumentation and preparation of this kind of tests. Their advantages and shortcomings are also discussed.