Design And Performance Analysis Of Double-tail Flap Sail

The growth of the global economy and the increase of the world trade have promoted the shipping industry to enter the stage of rapid development.As a result,the shipping industry becomes the main window of energy consumption and pollution.As the fuel prices rise in recent years and the International Maritime Organization on the ship's energy-saving emission reduction made stringent requirements,the major international shipping companies are actively looking for new ways of energy-saving emission reduction of ships and increased investment in new energy development.As a clean,non-polluting,inexhaustible natural energy,wind has been of concern.Therefore,as a major way to use wind energy the sail become a hot spot in shipping industry around the world.It is found that although there are many literatures on the research of wind-sailing and navigation,most of them are still on the optimization of traditional windsurfing.The study of new windsurfing with excellent aerodynamic performance and taking into account the form of windsurfing remains to be continued.Therefore,proposing a new sail which have better aerodynamic characteristics than modern traditional sailing sails,will vigorously promote development of windsurfing research of our country in the field of sail-assisted ship.In such background and purpose,this paper mainly completed the following content:(1)A new type of sail with two self-adjustable rear flap sails which can nest and retract automatically is proposed.By analyzing the aerodynamic performance of different types of modern sails,the main sails of the new type sail are selected with simple control system and good energy-saving effect.Combined with the Boeing aircraft lifting device sail structure was designed,and ultimately a new sail with horizontal fold,vertically nested retractable form was invented;(2)Based on CFD,the optimal combination of new sail parameters was designed.The main dimensions of sail were designed for the 45000 DWT Jianghai direct bulk carrier.The single parameter of sail flaps which influence the sail's lift,drag and thrust performance was analyzed by control variable method.The optimal combination of the parameters of the sail flaps was obtained by to produce the thrust effect maximization;(3)The analysis of the new windsurfing of the aerodynamic performance and energy saving effect: According to the combination of the sail-flap parameters,the optimal thrust coefficient and the lateral thrust coefficient curve of the windsurfing are obtained,and compared with the modern sail and the new-type windsurfing performance abroad.The results show that the aerodynamic performance and energy saving effect of the double-tail flap sails are better than those of other kinds of windsurfers in the partial wind direction,which has a good propulsive efficiency and energy saving effect;finally,according to the previous experience in the stability of the sailing and the stability of the ship,the stability of the double-tail flail navigating ship is initially checked,which provides reference for the future sailing in practical application;(4)Simulation of direct navigation of sail-assisted ship: According to the mathematic model of the sail-assisted ship,the heading control system is used to simulate the direct navigation of the ship with different wind speed and different wind speed.The simulation result shows that in the normal marine environment,the ship which install the double-tailed flaps with using the heading control system can get a reliable sailing thrust,at the same time,can ensure the course of the ship navigation course stability.