基于静水池模型试验的金枪鱼围网沉降性能研究

The Sinking Performance of Tuna Purse Seine Based on Model Test in Tank

基于重力相似准则,通过静水池模型试验研究下纲重量、放网速度和网衣材料对围网下纲沉降性能的影响。研究得出以下结论:(1)金枪鱼围网网翼后部下纲沉降速度最快,其次为网翼中部和取渔部;(2)下纲重量和放网速度与下纲沉降速度呈显著的正相关关系(P<0.01);(3)同等条件下,涤纶(PES)模型网下纲沉降性能显著优于聚酰胺纤维(PA)模型网,可能与涤纶材料密度较大有关;(4)放网速度1.5m/s和下纲重量47.5g/m条件下,PA材料模型网的网翼中部下纲沉降速度变化规律为先短暂上升,尔后呈快-慢-快趋势下降,平均沉降速度为0.12m/s。

Based on the gravity similarity criterion,the purse seine model experiment was carried out in cyliner-shaped tank to study the sinking performance of tuna purse seine.The foot line sinking speed of the end-part of purse seine was fastest,and then was mid-part of purse seine and bunt.A significant positive correlation was found between the foot line weight,setting speed and the foot line sinking speed（P〈0.01）.Under the same condition,the sinking performance of polyester（PES）model was better than polyamide（PA）model,the material density maybe the primary cause.Under the condition of that setting speed was 1.5m/s and foot line weight was 47.5g/m,the foot line sinking speed of mid-part of PA model had a briefly increase at the beginning,then decline following a fast-slow-fast trend,the average sinking speed was 0.12m/s.