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The gear shape and cross section of sweep at mouth of a bottom trawl

저층 트롤의 그물입구 형상과 소해 단면적

  • Park, Hae-Hoon (Fisheries Resources Division, East Sea Fisheries Research Institute, NFRDI) ;
  • Cho, Bong-Kon (Marine Science & Production Major, Kunsan National University) ;
  • Ko, Gwang-Su (Marine Science & Production Major, Kunsan National University) ;
  • Chang, Ho-Young (Marine Science & Production Major, Kunsan National University)
  • 박해훈 (국립수산과학원 동해수산연구소 어업자원과) ;
  • 조봉곤 (군산대학교 해양생산학) ;
  • 고광수 (군산대학교 해양생산학) ;
  • 장호영 (군산대학교 해양생산학)
  • Published : 2008.05.31

Abstract

Estimation of the gear shape and cross section of sweep at mouth of a bottom trawl net was described and applied to the field experiments obtained with the Scanmar system. The shape of the trawl net from wingend to the beginning of codend was assumed to be part of an elliptic cone of which the cross section was ellipse, and that of the float rope be of form $y_f=a_fx^{bf}$. In case of a bottom trawl with warp 180m long, the radius of ellipse, the cross section of sweep at mouth, the eccentricity of the ellipse, the inclination angle of float rope and the contribution of the side panel to net height were estimated in accordance with towing speed. The horizontal radius of the upper ellipse increased with increasing towing speed, the eccentricity of it became slightly bigger as increasing the towing speed which meant the shape of it being flat. And the inclination angle of the float rope was about between 7 and 12 degrees in case of the above bottom trawl.

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