A 4 DOF simulation model developed for fuel consumption prediction of ships at sea
A 4 DOF simulation model developed for fuel consumption prediction of ships at sea
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DOI：
10.1080/17445302.2018.1559912
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发表时间：
2018-12
影响因子：
2.1
通讯作者：
F. Tillig;J. Ringsberg
中科院分区：
文献类型：
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作者：
F. Tillig;J. Ringsberg
摘要本研究提出了一种新的船舶海上油耗预测仿真模型。该模型考虑了海上环境(风、浪和洋流)所产生的外力和力矩，并求解了具有涌浪、漂移、偏航和横倾四个自由度的船舶的力和力矩平衡。为了捕捉非自愿的速度损失，模型中包括了发动机限制。通过将现有的功率预测模型、数值标准船体和螺旋桨系列以及许多经验方法相结合，该仿真模型可以应用于常规船舶，在分析开始时可获得的信息非常有限，例如主尺寸、发动机转速和螺旋桨转速。此外，还提供了风力辅助推进组件。目前的研究描述了四自由度模型的细节及其在波罗的海航道上的三个案例研究中的适用性，这些案例具有现实的天气预报。研究的主要结论是，对比基于1自由度和4自由度的仿真结果，预测的油耗存在较大差异，建议采用4自由度的仿真模型。结果表明，在分析风助推进船舶时，考虑偏航力矩平衡和舵角限值是至关重要的。比较和讨论了非自愿速度损失的实例和不同的运行模式，并讨论了使用风助装置运行船舶时可能出现的螺旋桨后部空化和发动机失速问题。
ABSTRACT The study presents a new simulation model for the prediction of the fuel consumption of ships at sea. The model includes external forces and moments caused by the environment at sea, i.e. wind, waves and ocean currents, and solves the force and moment balances for the ship with four degrees-of-freedom (4 DOF), i.e. surge, drift, yaw and heel. To capture involuntary speed losses, engine limits are included in the model. By combining an existing power prediction model, a numerical standard hull and propeller series, and numerous empirical methods, the simulation model can be applied to conventional ships with very limited information available at the outset of an analysis, e.g. the main dimensions, engine rpm and propeller rpm. Additionally, a wind-assisted propulsion component is available. The current study describes the details of the 4 DOF model together with its applicability on three case studies on a ship route through the Baltic Sea with realistic weather forecasts. The main conclusions of the study show that there are considerable differences in the predicted fuel consumption when comparing simulation results based on 1 DOF and 4 DOF; the 4 DOF simulation model is recommended. It is shown that it is crucial to include the yaw moment balance and limits for the rudder angle when analysing ships with wind-assisted propulsion. Examples of involuntary speed losses and different modes of operation are compared and discussed, and potential problems with propeller backside cavitation and engine stalling when running a ship with a wind-assisted device are discussed.