高分子编结网片水动力特性水槽试验研究

高分子渔用材料在设施养殖和海洋渔业中的应用越来越广泛,对其水动力特性进行研究十分必要。试验采用不同网目系数和网线粗度的高分子编结试验网片进行水槽试验,倾角从0°变化到90°,设置水流速度从0.3 m/s开始,以0.1 m/s为梯度,逐渐增大至1.3 m/s。为减小尾流和湍流对试验结果的影响,使用流线型框架固定装配。经试验得到以下结果:(1)在网片与水流垂直时,阻力系数有随网目系数增大而增大的趋势,而在网片与水流平行时,阻力系数随网目系数增大而减小。(2)阻力系数有随雷诺数增大而逐渐减少的趋势,网片平面与流体运动方向速度垂直时,阻力系数在13001500后阻力系数变化不大。(3)阻力系数随着冲角的增大而增大并最终趋于稳定值。(4)升阻力系数比(K)在总体上有随倾角变大而先变大再变小的趋势,K的极值均出现在20°到30°内,最大K值约为0.41。(5)网片与水流垂直时,在1000

Experimental study on hydrodynamic characteristics of polymer knitted netting

The application of polymer fishery materials in facility culture and marine fishery is more and more extensive,so it is necessary to study its hydrodynamic characteristics.The polymer knitted netting with different solidity ratio and wire thickness was used for the flume test,with inclined angle changing from 0°to 90°and the flow velocity set from 0.3 m/s to 1.3 m/s at the gradient of 0.1 m/s.In order to reduce the influence of wake flow and turbulence on the test results,the streamlined frame was used in fitting out.The test results are as follows:(1)the drag coefficient increases with the increase of the solidity ratio when the netting is normal to the water flow and decreases with the increase of the solidity ratio when the netting is parallel to the water flow.(2)The drag coefficient is decreased gradually with the increase of Reynolds number.When the netting is normal to the velocity of fluid movement,the drag coefficient is steady in the range of 13001500.(3)The drag coefficient increases with the increase of the angle of incidence and finally tends to be stable.(4)The lift-drag ratio(K)increases first and then decreases with the increase of inclined angle in general,with the extreme value between 20°and 30°and the maximum value about 0.41.(5)When the netting is normal to the water flow,in the range of 1000