波流作用下双体组合式网箱水动力特性研究

运用刚体运动学原理及集中质量方法,建立了双体组合式网箱浮架、网衣、锚绳及浮子的受力运动方程数学模型,利用物理模型试验对数学模型进行了验证.结果表明,所建立的数学模型具有较好的可靠性及准确性.在此基础上运用数学模型,计算了在不同波流工况下,双体组合式网箱的锚绳受力、浮架运动及网衣变形.计算结果表明:在相同工况下,三类锚绳相比,连接锚绳受力最大,锚碇锚绳受力次之,网格锚绳受力最小；各种工况下,三类锚绳的受力随流速、波高的增加有不同程度的增加,随周期的增加有一定程度的减小；浮架中心点水平方向运动幅度总体表现为随流速的增加有一定程度的增加,竖直方向运动幅度总体表现为随流速的增加略有减小,浮架中心点水平、竖直方向运动幅度随波高、周期的增加均有一定程度的增加；浮架倾角随流速的变化不明显,随波高的增加有一定程度的增加,随周期的增加有一定程度的减小；网衣体积损失率总体上表现为随流速的增加有一定程度的增加,波高、周期变化对网衣变形影响较小.

A study on hydrodynamic characteristics of two net cages under effect of wave-current

Based on rigid kinematics theory and lumped mass method,a mathematical motion equation model of the two cages with floating collar,netting,mooring ropes and floats is developed.Then a series of physical model experiments are conducted to verify the mathematical model.The result shows that the mathematical model carries satisfactory reliability and accuracy.The forces acted on the mooring ropes,floating collar movement and net deformation under the different currents are calculated by using the model.The result shows that the forces on the bridle ropes are the largest followed respectively by forces on the main ropes and the grid ropes under the same condition,that forces on these three types of ropes increase differently as the current speed and the height of waves increase,and that they decrease as the period of wave increase.It further reveals that the horizontal amplitude of floating collar increases to an extent and the vertical amplitude decreases slightly as the current speed increases,that the horizontal and vertical amplitude of floating collar increases together as the height and the period of wave increase,that the inclination angle of floating collar is not influenced noticeablely by the current speed,but increases to a degree as the height of wave increases and decreases as the wave period increases,and that the rate of netting deformation increases slightly as the current speed increases but is not influenced significiently by the height and period of wave.