圆形曲面网板水动力学性能研究

Study on the Hydrodynamic Performance of Circular Cambered Otter Board

拖网是现代渔业主要作业方式之一,其中单船拖网是拖网渔业中最常见的作业方式。网板是单船拖网系统的重要属具,主要为拖网作业提供水平扩张力。本文通过水槽模型试验和数值模拟研究圆形曲面网板的水动力性能。通过数据处理,获得该网板的升阻力系数、升阻比以及压力中心系数等水动力参数,并根据数值模拟结果分析网板周围的流场流态。结果显示,该网板既有较大的升力系数,又有较高的升阻比,且该网板的曲面外形及导流板结构可有效延缓流的分离,从而增大网板的临界冲角;数值模拟结果与模型试验结果比较近似,对网板最大升力系数及最大升阻比的模拟误差均低于10%,且数值模拟可以有效预测网板的临界冲角。本文建议在条件允许的情况下,利用水槽试验与数值模拟方法开展网板水动力学性能研究。

Trawling is one of the main methods of modern fisheries, of which the single trawling is the common operation types. Otter board is the vital components of a single trawler system;it can provide the desired horizontal opening of a trawl net. In the present study, the hydrodynamic of a circular cambered otter board was studied using flume tank experiment and numerical simulation. The lift/drag coefficient, lift-to-drag ratio and center-of-pressure coefficient were obtained during the data processing, and the flow distribution around the otter board was analyzed according to the numerical results. It showed that the otter board had a good hydrodynamic performance for its high lift coefficient and lift-to-drag ratio, and the camber/deflector structure can delay the flow separation. Numerical simulation results showed a good agreement with experiment ones and could predict the critical angle of attack. Simulation errors the maximum lift coefficient and lift-to-drag ratio were under 10%. Given the otter boards are operated in water, it was suggested to apply both flume tank experiment and numerical simulation to study the hydrodynamic performance of otter board.