矩形曲面网板水动力性能的数值模拟

刘圣聪+刘佳茗

摘 要：拖网网板为网衣提供水平张力，是拖网作业系统非常重要的渔具构件之一。该文利用CFD软件FLUENT研究了展弦比对矩形曲面网板其水动力性能的影响。研究中设计了2种不同展弦比λ的网板，在流速1.54m/s，迎流冲角α = 0°～50°时，建立数值水槽进行数值模拟，得到网板的阻力系数Cd、升力系数Cl、俯仰力矩系数Cm和升阻比K，对比不同网板的水动力性能差异。结果表明，1号网板（λ = 2.0）与2号网板（λ = 1.5）的最大升力系数分别为0.85（α =15°）和0.92（α = 42°）；最大升阻比分别为9.59和8.35，俯仰力矩系数的绝对值分别为0.013和0.001。可见，展弦比越大，临界冲角和Cl值越小，最大升阻比越高，但稳定性越差。研究结果可为拖网网板的结构优化设计提供参考。

关键词：拖网网板；展弦比；水动力学性能；数值模拟

中图分类号 S141 文献标识码 A 文章编号 1007-7731（2017）18-0092-04

Numerical Simulation on Hydrodynamic Performance of Rectangular Otter Boards with Different Aspect Ratios

Liu Shengcong et al.

（Dalian Tianzheng Industrial Co. Ltd，Dalian 116001，China）

Abstract：The otter board is a vital component for the efficient expansion performance of an otter trawl system. The numerical CFD code ANSYS fluent was conducted for rectangular otter board model to study the effect of aspect ratio on hydrodynamic performance. 2 different kinds of aspect ratio of otter boards were numerical simulated using the FLUENT with the flow velocity at 1.54m/s and the angle of attack measured from 0° to 50°. The cal-culated drag coefficient Cd，lift coefficient Cl，pitching moment coefficient Cm，lift to drag ratio K and the relations curve of these value and angle of attack were compared. The results showed that the maximum lift coefficient of otter boards 1 and 2 was 0.85（α =15°） and 0.92（α =42°），the maximum lift to drag ratio was 9.59 and 8.35，and the absolute value of pitching moment coefficient was 0.013 and 0.001 respectively. The result indicated that the greater the aspect ratio，the smaller the critical angle of attack and lift coefficient，the higher the maximum lift to drag ratio，but the worse of stability. The results would provide reference for the structural optimization design of trawl otter board.

Key words：Otter boards；Aspect ratio；Hydrodynamic performance；CFD analysis

拖網作业具有灵活、高效、适应性强等特点，是最常见的一种捕捞方式，也是目前我国远洋捕捞中最主要的作业方式之一。网板是单船拖网系统中的重要组成部分，其水动力性能的优劣，关系到网具能否得到充分的扩张，从而直接影响到拖网渔具的渔获性能和经济效益[1-2]。因此，对网板水动力性能的研究以及对新型网板的开发，一直是国内外渔业工程研究者的关注重点。

挪威、日本、法国等渔业发达国家对网板水动力性能的改进研究较早，相继开发出大展弦比矩形曲面网板、综合型网板（椭圆形曲面开缝网板）、立式V型曲面网板和矩形V型曲面开缝网板等各种高性能网板[3]。……