| 摘要 |
There is provided a trawl-net collecting apparatus of net-mouth inclination maintainable type capable of autonomously maintaining a posture thereof. The present invention is a trawl-net collecting apparatus of net-mouth inclination maintainable type in which a trawl net is attached to a substantially rectangular cylindrical frame, the trawl net being formed of an upper net, a lower net, and a pair of side nets, and the trawl net having a shape formed of a body part of a quadrangular trapezoid shape and a cod-end part connected to an end of the quadrangular trapezoidal body part, wherein each of the side nets attached to the frame has a longer side and a shorter side as an upper side and a lower side, and a side defining a net-mouth edge defines a side-net front edge inclination angle (gamma), which satisfies a relationship represented by the following expression (1), relative to a bottom side of an isosceles trapezoid having the shorter side as a shorter leg, so that the frame autonomously maintains an inclination angle (beta) due to a resistance and a lift of a water flow against the net. <?in-line-formulae description="In-line Formulae" end="lead"?>(y1CDtheta1-x1CLtheta1)S1+(y2CDtheta2+x2CLtheta2)S2+2ySCDthetaSSS+2awf sin beta/(rhoalphaV2)=0 (1)<?in-line-formulae description="In-line Formulae" end="tail"?>
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