基于模型试验的秋刀鱼舷提网纲索张力性能研究

根据2014年11—12月进行的秋刀鱼(Cololabis saira)舷提网静水槽模型试验测定的网具数据,通过多元线性回归分析了模型网绞收过程中的张力变化,以及绞网速度和下纲配重与模型网网具张力的关系,试图研究涤纶材料的模型网网具起网张力性能。试验结果表明:(1)模型网侧纲、下纲的张力在绞网过程中随时间均呈逐渐增加的趋势,在绞网过程即将结束时张力达到最大值。(2)模型网侧纲、下纲张力均随绞网速度的提高而增加,并随着绞网速度的提高增速加快,不同绞网速度组之间张力变化存在显著性差异(P0.05);当绞网速度在0.12~0.36 m/s之间时,网具张力变化比较稳定;绞网速度在0.36~0.60 m/s时网具张力增加的幅度较大。模型网侧纲、下纲张力随下纲配重的增加逐渐提高,但影响并不显著。

Factors influencing the rope tension of saury stick-held lift nets

We evaluated the influence of haul speed and leadline weight on net tension inCololabis saira stick-held lift nets. Tests were carried out in a water tank using a scale model net in November–December, 2014. The tension on the siderope and leadline of the model net increased with haul time. The tension approached a maximum near the end of the haul. The tension on the model net siderope and leadline increased as the hauling speed increased and the rate of increase in net speed accelerated as the hauling speed increased. The hauling speed at 0.36–0.60 m/s had a significant effect on rope tension (P<0.05), while at hauling speed of 0.12–0.36 m/s, the change in rope tension was stable. The tension in the model net sideline and the leadline increased when the lead-line weight increased, though there was no effect on rope tension. Our observations provide insight into ways to improve rope tension performance and a reference for fishing operations.