Experimental and numerical study on the parametric roll of an offshore research vessel with extended low weather deck

Abstract

After over 10 years' development, the International Maritime Organization (IMO) published the 2nd Generation Intact Stability Criteria (SGISC), including Parametric Roll (PR) criteria to avoid its serious harm to the safety of ship navigation. With the trial of SGISC, ships with extended low weather deck, such as typical Offshore Research Vessel (ORV), are found may be vulnerable to PR too. Relative research on such kind of ship is insufficient, because most of previous researches focus on conventional high freeboard ships such as container ships or passenger ships. With an aim to study the PR characteristic of ships with extended low weather deck, an experimental investigation and numerical comparison investigation are carried out. The effect of highly nonlinear water-on-deck phenomena caused by ORV's extended low weather deck on PR response is specially investigated. Regarding numerical simulation of ORV's parametric roll, the effects of assessment accuracies of GZ curves in waves and roll damping coefficients are analyzed. As a result, it was found that parametric roll may occur for ORV's in adverse sea conditions when overtaking of green water is seen on the deck in following wave conditions. It is recommended to account for this specific issue when analyzing PR for ORV's.