水下拖缆接触海底时的数值模拟

The Numerical Simulation of Towed Cable Concerning Seabed Interaction

为分析拖缆和海底的相互作用,研究了水下拖缆和海底有接触时的运动响应.首先,基于集中质量法给出了三维非均匀拖缆运动的数学模型,并采用四阶龙格库塔方法进行数值求解.其次,将海底视为三维不规则连续的刚性曲面,其中海底对拖揽的作用力包括法向反作用力和切向摩擦阻力两部分,并计入了带速着底时的冲击响应,藉此考虑了它们对拖缆动力学性能的影响.最后,由仿真计算给出拖揽在不同运动状态下的响应并进行了分析.结果表明,摩擦阻力和冲击对拖揽动力学性能影响显著.

A numerical method for the dynamic simulation of cable-seabed interaction was developed. It describes a mathematical model of 3-D cable based on the LPM （Lumped Parameter Method）, which can be solved by 4th-order Runge-Kutta method. The seabed is modeled as an irregular continuous rigid surface, and the forces exerted by the seabed consist of normal counterforce and isotropic tangential friction resistance. The impact response is also taken into consideration by means of classic mechanics, conse- quently the friction and impact effect on the cable dynamics is discussed. Then the numerical simulation cases under different situations were presented with relevant discussion. The results illustrate that the friction and impact have an evident effect upon the dynamics of the cable.