Design And Optimization Of Wind Drag Reduction Device For Bow

With the energy problem on the earth becoming more and more prominent,energy saving and emission reduction are paid more and more attention in various fields,the International Maritime Organization is also promoting the implementation of EEDI actively.The research on drag reduction and energy conservation in the field of ships has been focused on reducing the water resistance of ships for a long time.In recent years,scholars have begun to pay more attention to the details of ship drag reduction and energy saving,including the impact of wind loads.The study of reducing ship wind resistance is particularly important for larger ships above the waterline.At the same time,compared with wind tunnel test,CFD software can show the flow field more clearlyOn the premise that most of the research on ship wind resistance reduction is profile optimization.In this paper,numerical simulation method is used to design and optimize the bow diversion drag reduction device.Firstly,the above part of the waterline of 3100 TEU container is modeled,and the part which has little influence on the wind resistance is simplified.Next,the model is preprocessed.The numerical calculation of wind resistance is carried out and its reliability is verified by comparison with Van Berlekom's method..Then,eight types of drag reduction devices attached to the bow are designed and calculated,and the preliminary design scheme is determined by comparing the results.The optimization of five parameters affecting the drag reduction effect of bow diversion drag reduction device is completed by orthogonal experiment and control variable method.By analyzing the flow field,the optimum drag reduction scheme with wind drag reduction effect up to 32.47% is determined and its drag reduction mechanism is expounded.The research shows that the device reduces the pressure on the bow windward side and eliminates the eddy zone caused by the air return phenomenon significantly,which makes the flow of airflow in the flow field more stable.Finally,the possible influence of the installation of the device on the bare ship is briefly analyzed,which includes comparing the drag reduction effects of drag reduction devices under different relative wind speeds,checking the strength with Workbench,and calculating the stability with Maxsurf.The reliability of the designed device is verified,which can be used as a reference for the study of wind resistance reduction of ship's additional devices.