水深对系泊起重船运动影响的数值与试验分析

Numerical simulation and experimental comparison about water depth's influences to moored floating crane ship

以一艘现役起重船为研究对象,对其进行不同水深(46 m和36 m),缩尺比1∶50的模型试验。采用基于二次传递函数QTF的时域准静态分析法对实际尺度起重船与系泊系统进行耦合数值分析,并与试验结果进行比较。结果表明,当水深变浅时,浅水对二阶载荷的影响是系泊力明显的主要因素,浅水对一阶载荷的影响有限。在保持系泊系统刚度线性不随水深变化的前提下进行了三个水深吃水比的数值模拟计算,结果表明,对于系泊起重船,随着水深的减小,二阶定常力有所增大;浅水对差频载荷的影响在30 m水深(吃水水深比d/h=0.27)时变得明显。对于浅水系泊系统的相关分析需要充分考虑水深对二阶慢漂运动的影响,保证系泊系统的安全。

Taking a multi-point moored floating crane ship as an example,a model test at 46 m and 36 m water depth is performed with model scale 1：50.Based on full QTF method,an actual scale time domain quasi static numerical simulation is done and compared with model test value.The results show that with the water depth decreasing,the shallow water effect on second-order load is the major reason for mooring force increasing,and the shallow water effect on the first-order load is very limited.Maintaining the mooring system stiffness is linear and does not vary with water depth,and a numerical simulation is done with three draft depth ratio.The results show that for moored crane ships,as water depth decreases,the second-order steady force increases,and the shallow water effect on slowly drift load becomes apparent in 30 m water depth（draft depth ratio d/h=0.27）.For shallow water mooring analysis,the second-order shallow water effects should be fully considered to ensure the safety of mooring systems.