Hydrodynamic characteristics of vertical V type otter board.

• DOI: 10.2331/suisan.56.1815
• Publication Date: 2011-09-20T04:17:54Z
• Authors: Ko Matuda; Fuxiang Hu; Satoshi Ishizawa
• Keywords: 0106 biological sciences; 0401 agriculture, forestry, and fisheries; 04 agricultural and veterinary sciences; 01 natural sciences

The hydrodynamic characteristics of a vertical V type otter board, which has been widely used recently by Japanese trawlers, were studied using a model with a dihedral angle and a sweepback angle. The model with 309cm2 wing area and 14.1% camber ratio were rigged for an attack angle ranging from -5° to 90°. The lift, drag and moment were measured by a three-component balance on a circulating water tank. Results showed that the maximum lift coefficient was 1.27 while the maximum lift-drag ratio was 4.03 when the stall angle was 22°. The range of the common attack angle sustaining 75% of maximum lift-drag ratio was comparatively wide (17°), and variation of the coefficient of pressure center was only 10%. It follows that this type of otter board is of good stability.