横傾斜を含む線形応答モデルによる船舶操縦性の検討 [in Japanese] Effect of Roll Motion on Ship Manoeuvrability by a Rudder to Yaw Response Equation [in Japanese]
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Abstract
Many researches have been done about the effect of a steering motion on roll motion, as the turning motion sometimes introduces a capsizing of ship and makes serious disasters. On the contrary, the researches of the effect of a roll motion on the manoeuvrability are very few, and the mechanism is not clear. In 1970s after the construction of a highspeed container ship, it began to be pointed out that the navigation difficulty arises with such ships, and then the research on the latter was started. Eda<SUP>1)</SUP>, Hirano<SUP>2)</SUP> and Sohn<SUP>3)</SUP>respectively proposed the mathematical models of manoeuvring motion including the roll motion, and pointed out that the coursekeeping ability becomes worse and the turning radius becomes smaller when ship speed increases. This tendency becomes remarkable with lower <I>GM</I>. In these researches, although the turning motions were well simulated using each mathematical model,the mechanism or structure of the roll effect on the manoeuvrability has not been clarified yet.In this paper, the author introduces the rudder to yaw response equation from the simple linear mathematical model, and has clarified the following principal structure regarding to the effect of the roll motion on ship manoeuvrability. 1) The turning moment <I>Y<SUB>φ</SUB>φ</I> and <I>N<SUB>φ</SUB>φ</I> induced by the roll angle become the key parameter that strongly affects the coursekeeping and turning abilities of ship. This tendency becomes remarkable when roll angle becomes larger by the lower <I>GM</I> and higher Froude number.2) For a highspeed merchant ship whose (<I>N'<SUB>φ</SUB></I> <I>Y'<SUB>φ</SUB>l'<SUB>β</SUB></I>) becomes larger in negative due to the large bulbous bow for example, the larger negative (<I>N'<SUB>φ</SUB></I> <I>Y'<SUB>φ</SUB>l'<SUB>β</SUB></I>) makes the less stability on course and the stronger turning ability, which may make the smaller turning radius and the larger overshoot angle in Zmanoeuvre.3) On the other hand, when (<I>N'<SUB>φ</SUB></I> <I>Y'<SUB>φ</SUB>l'<SUB>β</SUB></I>) is a positive value, it becomes a phenomenon completely contrary to the above.
Journal

 Journal of the Japan Society of Naval Architects and Ocean Engineers

Journal of the Japan Society of Naval Architects and Ocean Engineers (13), 1118, 20110601
The Japan Society of Naval Architects and Ocean Engineers