HDPE圆形网箱单点系泊与多点系泊受力特性模拟分析比较

Comparison on the Forces between HDPE Circular Single-Point Mooring Net Cage and Multiple-Points Mooring Net Cage in Waves and Current

基于建立的网箱整体数学模型,以40 m周长的单点系泊(Single-point mooring)HDPE重力式圆形网箱为研究对象,对不同波浪和流速组合条件下的网箱波流力、锚绳力进行了数值计算,并与传统多点系泊(Multiple-points mooring)网箱受力结果进行了比较,分析探讨了水深、网衣高度对两种系泊形式网箱锚绳受力的影响。结果表明,无论是在纯波还是波流共同作用条件下,单点系泊网箱所受的波流力均要小于多点系泊网箱情况。在纯波条件下,两种系泊形式网箱所受的锚绳力相差较小。但在波流组合条件下,单点系泊网箱所受的锚绳力约为多点系泊网箱锚绳力的1.5倍。两种系泊形式网箱锚绳力均随着网衣高度的增加而增大,随着水深的增加而减小。当水深从20 m增加到50 m时,单点系泊网箱锚绳力减小幅度29%以上,这为今后我国深水网箱的深水化发展提供了一定的理论参考依据。

Based on the numerical model of net cage, by taking single-point mooring gravity circular cage with perimeter of 40 m as research object, the wave-current forces and the mooring line forces on the net cage were calculated under the following various combined conditions. Setting the value of wave and current elements： wave heights H=4-6 m, wave periods T=6.0-8.6 s, current velocities U=0.0-0.9 m/s. The forces of single-point mooring net cage were compared with that of multiple-points net cage under different conditions, and the effect of sea depth as well as net height on the mooring line forces of the two kinds of cages were analyzed and discussed. The results indicated that the wave-current forces on the single-point mooring cage were less than that of multiple-points mooring cage under whether pure wave or current combined with wave. Under the pure wave conditions, the difference of mooring line forces between the single-point cage and multiple-points cage was small. However, under a combination of wave and current conditions, the mooring line force on single-point cage was about 1.5 times that of multiple-points cage. The mooring line forces of the two kinds of cage increased with net height increasing while decreased with increasing of sea depth. The mooring line forces on the single-point cage decreased by more than 29% when the sea depth increased from 20 m to 50 m, which provided some theoretical reference to the development of net cage towards to deep-water sea area.