Hydrodynamic characteristics of a biplane-type otter board,equipped with nylon canvas of 2 mm in thickness was investigated through flume-tank experiment in this study.A series of predesigned structures with different gap-chord ratios G/c(0.75,0.90,1.05),stagger angles θ(30°,45°,60°),and proportions of flexible area relative to the whole wing area fr(0,55％,65％,75％),at an aspect ratio of 2.0 and a camber ratio of 15％,were experimentally carried out.The results showed the solution referring to the usage of flexible canvas replacing part of rigid structure for the biplane-type otter board was efficient for the trawling in the middle or shallow water area.The improvement of lift and stability for the biplane-type otter board was concluded,and drag of the structure was reduced by 1.9％at fr =55％.In addition,the coefficient of variation of the lift and drag coefficient at different current velocities were 2.69％and 2.28％,respectively,which was smaller than those at relatively large proportion of the flexible area.Compared with the other tested structures,the frame-type flexible structure with the gap-chord ratio of 0.9 and a stagger angle of 45° and the proportion of the flexible area of 55％,performed best,and its drag was reduced by 5.72％and lift increased by 4.8％,compared with the rigid biplane-type otter board at the angles of attack from 18° to 28°.

XIE Si-jie;WU Ru-ke;HU Fu-xiang;SONG Wei-hua

Department of Marine Fisheries,Zhejiang Ocean University,Zhoushan 316022,China;Key Laboratory of Marine Fishery Equipment and Technology of Zhejiang,Zhoushan 316022,China;Tokyo University of Marine Science and Technology,Minato,Tokyo 108-8477,Japan

中国海洋工程（英文版）

[1]XIE Si-jie;WU Ru-ke;HU Fu-xiang;SONG Wei-hua-.Hydrodynamic Characteristics of the Biplane-Type Otter Board with the Canvas Through Flume-Tank Experiment)[J].中国海洋工程（英文版）,2022(06):911-921

Biplane,Otter,biplane,otter,trawling

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