Ship hull structural damages are often caused by extreme wave-induced loads. Reliable load predictions are required to minimize the risk of structural failures. One conceivable approach relies on direct computations of extreme events with appropriate numerical methods. In this perspective, we present a systematic study comparing results obtained with different computational methods for wave-induced loads and motions of different ship types in regular and random irregular long-crested extremes waves. Significant wave heights between 10.5 and 12.5 m were analyzed. The numerical methods differ in complexity and are based on strip theory, boundary element methods (BEM) and unsteady Reynolds-Averaged Navier–Stokes (URANS) equations. In advance to the comparative study, the codes applied have been enhanced by different researchers to account for relevant nonlinearities related to wave excitations and corresponding ship responses in extreme waves. The sea states investigated were identified based on the Coefficient of Contribution (CoC) method. Computed time histories, response amplitude operators and short-term statistics of ship responses and wave elevation were systematically compared against experimental data. While the results of the numerical methods, based on potential theory, in small and moderate waves agreed favorably with the experiments, they deviated considerably from the measurements in higher waves. The URANS-based predictions compared fairly well to experimental measurements with the drawback of significantly higher computation times.

中文翻译：

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波浪运动和载荷计算方法的比较研究

船体结构损坏通常是由极端波浪感应载荷引起的。需要可靠的载荷预测以最小化结构故障的风险。一种可能的方法依赖于使用适当的数值方法对极端事件进行直接计算。从这个角度出发，我们提供了一项系统研究，比较了在规则和随机的不规则长波极端波中，波浪计算的载荷和不同船舶类型的运动所采用的不同计算方法所获得的结果。分析了10.5至12.5 m之间的重要波高。数值方法的复杂性有所不同，并且基于带状理论，边界元方法（BEM）和非稳态雷诺平均Navier–Stokes（URANS）方程。在进行比较研究之前，不同的研究人员对所应用的代码进行了增强，以解决与波浪激励和极端波浪中相应的船舶响应有关的非线性问题。基于贡献系数（CoC）方法确定了调查的海况。系统地将计算的时间历史，响应幅度算子以及船舶响应和波高的短期统计数据与实验数据进行了比较。虽然基于势能理论的数值方法的结果在中小波浪中与实验吻合良好，但与高波浪中的测量结果有很大的出入。基于URANS的预测与实验测量相当好，但缺点是计算时间明显更长。