On Wave Condition for Model Experiments of Ships in Following and Quartering Seas

Abstract

The feature of encounter waves a ship will experience when navigation in following and quartering seas is investigated by tank experiments and numerical simulations. The energy spectrum of encounter waves becomes narrow-banded shape with a high peak on the encounter frequency domain, when the ship speed-wave period ratio is within a certain range. This shape of spectrum connects closely with the specific feature of encounter waves that a ship will be attacked by a series of very high waves which sometimes causes danger of capsizing. This is named as "Dangerous encounter wave grouping phenomena" and the authors propose that any model experiment of ships in following and quartering seas should include this dangerous encounter wave grouping zone determinable on the "V/T diagram" for test conditions and to conduct the test in highest wave group in irregular waves.