金枪鱼延绳钓单丝和绳索的惯性力系数和阻力系数研究OA北大核心CSTPCD

Inertia force coefficient CM and resistance coefficient CD of monofilament and rope used in tuna longline gear directly affect the computational speed and accuracy of numerical simulations of fishing gear.In this study,wave forces acting on seven types of monofilament and rope materials for tuna longline gear under regular wave conditions were investigated through wave tank experiments.CM and CD for respective materials were calculated using the Morison equation and employing the least squares method.The variations of CM and CD with Keulegan-Carpenter number KC and Reynolds number Re were analyzed.The results indicate that:(1)Under the same wave height,the wave forces acting on experimental materials gradually increase with increasing wave period.(2)Under the same wave period,the wave forces acting on experimental materials gradually increase with increasing wave height.(3)With increasing diameter,the wave forces acting on experimental materials also increase.(4)For three types of nylon monofilament,CD gradually increases with the increasing KC while CM remains relatively stable,and CM and CD exhibit an increasing trend with the increasing of Re.(5)For three types of polypropylene ropes,CM increases with the increasing KC and Re,while CD stabilizes at lower KC numbers and decreases gradually with the increasing Re.(6)Polypropylene ropes coated with asphalt exhibit relatively stable CM and CD values.The obtained CD and CM values from this experiment can be applied to the numerical simulations of longline fishing gear.