| Wing-typed sail-assisted ships can reduce fuel consumption and CO2 emissions by using wind energy as an auxiliary thrust force,which is of certain significance for improving the level of ship energy efficiency.It is also a specific way for the shipping industry to implement the development strategic of"carbon peak"and"carbon neutrality".During the operation of wing-typed sail-assisted ships,the sails and navigational environment factors have a certain influence on the navigation status of the ship,which in turn affect the sailing resistance and energy efficiency level of the ship.Therefore,the decision of the optimal navigation status for the wing-typed sail-assisted ships is of certain significance for further improving the energy efficiency level of the ship.However,there is currently a lack of research on the optimization decision-making method of the navigation status of the wing-typed sail-assisted ships.The energy efficiency level of wing-typed sail-assisted ships can be further improved.Therefore,in order to further explore the improvement potential of the ship energy efficiency,the research on the energy-saving methods for optimizing the navigation status of the wing-typed sail-assisted ships based on the CFD simulation calculations is carried out.The specific research contents are as follows:（1）The wing-typed sail thrust characteristics and the hull resistance based on the CFD method is studied and calculated.The three-dimensional model of the target wing-typed sail is established,the aerodynamic characteristics of the sails are simulated and analyzed,and the lift coefficient and drag coefficient of the sails are obtained.In addition,a three-dimensional model of the target ship hull is established,and the simulation calculations of ship resistance at different sailing speeds were conducted under given sea conditions.The ship resistance characteristic curves at different sailing speeds are obtained,which can lay the foundation for the simulation calculation of wing-typed sail-assisted navigation ships;（2）Simulation calculation of resistance of wing-typed sail-assisted navigation vessels under different postures is carried out.A three-dimensional simulation model for the wing-typed sail-assisted ship is established.On this basis,the simulation calculations on the resistance of wing-typed sail-assisted under different trims and floating states,as well as different loading conditions are conducted.The resistance characteristic curves of the wing-typed sail-assisted ship under different working conditions,as well as the thrust of the sail,the lateral force of the sail,and the corresponding heeling angle of the ship,are obtained,which can provide a data basis for the decision of the optimal navigation status of the wing-typed sail-assisted ship.（3）Optimization decision-making method for optimal navigation status of the wing-typed sail-assisted ship is investigated.On the basis of calculating and analyzing the increased resistance caused by the rudder angle,as well as estimating the power and fuel consumption of the main engine under different navigational status,the power-trim curves of the main engine under full loaded and ballast status are obtained.Based on this curve,the optimal navigation status optimization decision for wing-type sail-assisted navigation ships under specific sea conditions was achieved.Namely,a stern inclination of 0.90°under full loaded condition is the optimal energy-saving navigation status,and a stern inclination of 1.20°under ballast condition is the optimal energy-saving navigation status.On this basis,a comparative analysis is conducted on the energy-saving effect of the optimal navigation status.The research results show that the proposed method for the optimal navigation status of the wing-typed sail-assisted ship can reduce fuel consumption by 3.96%at full load and 4.64%under ballast conditions under specific sea conditions.Therefore,the proposed method can effectively improve the energy efficiency level of the wing-typed sail-assisted ships. |
