Research On The Mechanism Of Windsurfing Pumping Based On Flapping Theories

It is the best opportunity for our windsurfing players to realize the break in winning gold along with the coming of Beijing Olympic game. Windsurfing is a multi-subject across sport, including aerography, hydrology, oceanography, hydrodynamics, aerodynamics, material science etc. In order to win an excellent achievement, the players should insist on system and science training for a period of time and have a perfect performance in the game on skills and tactics. Otherwise, some key skills of windsurfing should be researched deeply, especially the skill of pumping. Since it was allowed to pump in Barcelona, this skill has been used in game widely to improve the achievement evidently. However, the aerodynamics characters of sail during pumping, such as how the sail affects flow field around and the mechanism of high lift of pumping, are researched rarely. While, the discussion of these theories is vital to make correct skills and tactics for the game. This research is proposed based on this background.The aim of this thesis is to research the effect of the movement of pumping to the flow field and the aerodynamics characteristics of the sail in order to obtain some science theories, which can be used to make skills and tactics. For example, by research of distribution of the flow field, how to disturb the flow field by pumping to interfere adversaries and how to avoid this interference can be known. The optimal frequency and range of pumping can also be decided by comparing lift coefficient and drag coefficient of different instances.Based on many years research on windsurfing, after deep research on the movement of windsurfing, analysis of movement of birds, insects and fish, the mechanism of the windsurfing pumping based on flapping theories is addressed. The basis of this theory is discussed across-the-aboard, including the structure of the wings, process of movement, composition of the aerodynamic lift and the environment around the wings. The investigation methods and research production on the flapping movement are summed up, then the high-lift mechanism of flapping movement is analyzed, finally the mechanism of the windsurfing pumping based on flapping theories taking the fact of movement of windsurfing into account is expressed.The flow field around the windsurfing is predigested. On this condition the force equations and kinematics equations of windsurfing are described. The control equation, boundary conditions and initial conditions are discussed. After discussion, Fluent is adopted to model the movement of windsurfing with rigid sail. The computational results show that a high lift coefficient can be obtained by pumping. The results accord with the mechanism of windsurfing pumping based on flapping theories on the whole.As a deep step and complementarity, the solution to model the full course of windsurfing with FSI and make scale model experiment to improve and revise the mechanism of the windsurfing pumping based on flapping theories is suggested.