Abstract The shipping industry is the heart of international trading activities and the global economy. Maritime transport contributes to environmental pollution through the emission of greenhouse gases. New mandatory regulations aim at improving the environmental performance of ships by encouraging power reduction and alternative fuels. These requirements drew attention to the estimation of the ship performance in the presence of waves considering unconventional combustibles. Investigating the effects of waves on untraditional propulsion plants could help to design more environmentally friendly ships. The purpose of this paper is to determine the importance of the time-varying wake field, ship motions, propeller emergence, and engine response on the performance in waves of a marine propulsion system powered by a medium-speed LNG engine. This is performed by comparing the engine-propeller performance estimated by modelling the propulsion plant at three different levels of complexity. The results illustrated the poor prediction accuracy of the propulsion system performance in waves when the time-varying wake field, ship motions, and propeller emergence are neglected. The influence of the engine response on the performance prediction of the engine-propeller system was negligible. The outcomes of this paper demonstrate the importance of considering the effects of the waves on the propulsion system of a ship during the optimization phase.

中文翻译：

---

存在波浪时发动机-螺旋桨模型精度对船舶推进系统性能预测的重要性

摘要 航运业是国际贸易活动和全球经济的核心。海上运输通过排放温室气体导致环境污染。新的强制性法规旨在通过鼓励降低功率和替代燃料来改善船舶的环境绩效。这些要求提请注意在考虑非常规可燃物的情况下对船舶性能的估计。研究波浪对非传统推进装置的影响有助于设计更环保的船舶。本文的目的是确定随时间变化的尾流场、船舶运动、螺旋桨出现和发动机响应对由中速 LNG 发动机提供动力的船舶推进系统的波浪性能的重要性。这是通过比较通过在三个不同复杂级别对推进装置进行建模而估计的发动机-螺旋桨性能来执行的。结果表明，当忽略时变尾流场、船舶运动和螺旋桨出水时，波浪中推进系统性能的预测精度较差。发动机响应对发动机-螺旋桨系统性能预测的影响可以忽略不计。本文的结果证明了在优化阶段考虑波浪对船舶推进系统的影响的重要性。结果表明，当忽略时变尾流场、船舶运动和螺旋桨出水时，波浪中推进系统性能的预测精度较差。发动机响应对发动机-螺旋桨系统性能预测的影响可以忽略不计。本文的结果证明了在优化阶段考虑波浪对船舶推进系统的影响的重要性。结果表明，当忽略时变尾流场、船舶运动和螺旋桨出水时，波浪中推进系统性能的预测精度较差。发动机响应对发动机-螺旋桨系统性能预测的影响可以忽略不计。本文的结果证明了在优化阶段考虑波浪对船舶推进系统的影响的重要性。