This paper proposes a semi-empirical model to estimate a ship’s speed loss at head sea. In the model, the formulas to estimate a ship’s added resistance due to waves have been further developed to better consider the ship hull forms, in addition to other main particulars. Based on the model experimental tests of 11 ships in regular head waves, the new formulas have more flexible forms and can better fit the test results than other similar models. In addition, this model proposes a significant wave height based correction factor multiplied to the conventional integration to compute wave resistance in irregular waves. This factor is supposed to consider the impact of coupled ship motions in high waves on a ship’s added resistance due to waves. The model is validated by the full-scale measurement from two vessels, a PCTC and a chemical tanker. The encountered weather conditions along the sailing routes are extracted from the reanalysis metocean data. The results indicate that the proposed model can provide quite accurate predictions of ship speed loss in head sea operations.

中文翻译：

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头海船速损失预测的半经验模型及其全尺寸测量验证

本文提出了一种半经验模型来估计船舶在逆海时的速度损失。在该模型中，除了其他主要细节外，还进一步开发了估算船舶因波浪而增加的阻力的公式，以更好地考虑船体形状。基于11艘船在规则头浪中的模型实验测试，新公式形式更加灵活，与其他同类模型相比，能更好地拟合测试结果。此外，该模型提出了一个基于显着波高的校正因子，乘以传统积分来计算不规则波浪中的波浪阻力。这个因素应该考虑在高浪中耦合的船舶运动对船舶因波浪而增加的阻力的影响。该模型通过来自两艘船、一艘PCTC和一艘化学品船的全尺寸测量进行了验证。从再分析气象数据中提取沿航行路线遇到的天气条件。结果表明，所提出的模型可以提供相当准确的预测海上作业中的船速损失。