楕円柱の旋回運動について

概要

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In order to investigate fundamental properties of turning motion of a ship, movements of an elliptic cylinder were dealt theoretically with, when the cylinder in advance was steered suddenly in the perfect fluid. The resultant force on the cylinder in the direction of its long axis is a resistance in a case of stern rudder, while in bow rudder it becomes a negative resistance. But they are small and neglegible. The resultant force on the cylinder in the direction of its short axis is smaller than the lift of the rudder due to steering and acts in the contrary direction. Then the cylinder is on the bodily movement in the direction of the lift of the rudder. The resultant moment due to fluid pressure on the surface of the cylinder is smaller than the turning moment of the rudder and has the contrary sense. Then the turning motion of the cylinder is delayed. These effects is varied in accordance with the shape of the ellipse. The narrow form is effective, that is, it has better directional stability than the broadish one.
社団法人日本船舶海洋工学会の論文