复杂海况下水下拖缆数值分析研究

为了解复杂海况下风浪对水下拖缆的影响进行了动力学仿真研究。以P-M谱作为海浪谱密度公式,计算一组不同频率的组成波,采用线性波浪叠加法,计算由波浪引起的空间流场速度及加速度,推导叠加波的干扰力,将不规则波引入水下拖缆动力学模型中,采用四阶龙格库塔积分法对动力学模型进行数值求解,讨论拖缆在不同海况下的动力特性。结果表明,随着海况等级的提高,叠加波的频率范围逐渐降低,拖缆的垂向偏移量以及拖点处张力均会产生明显增加及波动,且其波动周期接近叠加波的平均周期;在不同浪向角的作用下,拖缆波动规律与规则波作用下类似,但也具有一些不规则波的特点。

Numerical analysis of underwater towing cable under complex sea state

In order to clarify the influence of wind and wave on underwater towing cables in complex sea state, the dynamic simulation of underwater towing cables in complex sea state is studied in this research. Using P-M spectrum as the formula of wave spectral density, a group of constituent waves with different frequencies are calculated. The linear wave superposition method in wave theory is used to calculate the velocity and acceleration of space flow field caused by waves, and irregular waves are introduced into the dynamic model of underwater towed cables. The fourth-order Runge-Kutta method is used to solve the dynamic model, and the response characteristics of the towline under different sea conditions are calculated and discussed. The results show that the frequency range of superimposed wave decreases gradually with the increase of sea level. The vertical offset of the towline and the tension at the towing point will increase and fluctuate obviously, and the fluctuation period is close to the average period of superimposed wave. Under the action of different wave directions, the fluctuation law of the towline is similar to that of the regular wave, but it also has the characteristics of irregular wave.