ROV脐带缆水动力分析

Hydrodynamic analysis of ROV umbilical cable

本文基于水动力软件OrcaFlex搭建了母船-脐带缆-ROV水动力模型,模拟近海海况下ROV的运行,探究ROV在不同运动模式下脐带缆受到的水动力特性。利用水动力软件AQWA获得母船被动运动下的RAO,采用OrcaFlex软件进行水动力仿真,获得脐带缆受到的有效张力、Strouhal频率和缆绳位移等一系列水动力响应。结果表明,ROV在进行平动或旋转运动时,脐带缆两端牵制力具有周期性;在缆长方向上,各个流向对应张力曲线的波动表现出平缓的特点,且中间张力较小,两端张力较大;将缆绳作为参考点,流体靠近ROV运动和母船的相对流速和Strouhal频率均越大。研究结果可为小型ROV脐带缆水动力分析提供有效的指导。

This paper built a mothership-umbilical cable-ROV hydrodynamic model based on the hydrodynamic software Orcaflex to simulate the operation of the ROV under offshore sea conditions and explore the hydrodynamic characteristics of the umbilical cable under different motion modes. The RAO of the mother ship was obtained by the hydrodynamic software AQWA. Based on the RAO data, Orcaflex software was used to conduct hydrodynamic simulation, and a series of hydrodynamic responses, such as the effective tension, Strouhal frequency and cable displacement, were obtained. The results show that, when the ROV is in translational or rotational motion, the restraining force at both ends of the umbilical cable is periodic;In the cable length direction, the fluctuation of the tension curve corresponding to each flow direction is gentle,and the tension in the middle is small, while the tension at both ends is large;When the cable is used as the reference point,the relative velocity and Strouhal frequency of the fluid near the ROV and the mother ship are larger. The hydrodynamic results can provide effective guidance for the hydrodynamic analysis of the umbilical cable of a small ROV.