【作者】 何海峰；

【导师】 郑伟涛；

【作者基本信息】 武汉理工大学 ， 水上运动装备工程， 2012， 博士

【摘要】 本文以夏季奥运会女子级别的NP帆板帆翼作为研究对象,利用数值模拟方法对NP帆翼在定常和非定常状态下的空气动力性能进行研究,运用理论流体力学、计算流体力学对帆翼空气动力特性进行了较为全面的分析,为运动员根据不同外界条件摇帆提供科学依据。研究首先采用STAR CCM+软件对文献资料中的帆翼SAIL1进行了定常状态下的数值计算,其计算结果与试验结果能较好吻合,验证了文献资料中采用的计算方法及STAR CCM+软件的适用性。NP帆翼的计算区域是以帆翼底边弦长为基准的前面8倍、上面8倍、左右8倍、后面16倍的长方体区域,采用6面体核心网格划分计算区域及其内部的帆翼。对NP帆翼定常状态下的数值模拟根据实际帆板竞赛所需最小风速条件,选取2m/s和3m/s风速作为入口边界条件,计算并对比了NP帆翼在不同风速、不同攻角下的升力系数和阻力系数,分析了NP帆翼的压力分布、流线分布及速度矢量分布在不同攻角下的变化情况。对NP帆翼非定常状态下的数值模拟根据运动员摇帆时帆翼的运动状态,将需要模拟研究的帆翼运动简化为三种运动方式：1、帆翼绕帆面展向方向来回转动;2、帆翼绕帆面弦向方向来回转动；3、帆翼沿垂直于帆面的方向来回振动。非定常状态下的计算区域内部构建了新的区域,以有效减小网格变形区域、避免计算量过大,同时保证数值计算的精度。数值模拟首先针对不同来流攻角下的NP帆翼绕展向方向来回转动的运动方式进行,得到了不同攻角下摇帆的升力系数、阻力系数和升阻比并进行了分析：针对NP帆翼绕展向方向转动时的最大升力系数及升阻比对应的攻角,模拟了不同运动方式下NP帆翼随幅度和频率变化的空气动力,得到了在不同状态下摇帆时的升力系数、阻力系数和升阻比,根据模拟结果研究了绕帆面弦向和绕帆面展向方向摇帆过程中帆翼面上的压力分布变化,分析讨论了NP帆翼在不同状态下的空气动力性能随幅度和频率的变化关系。研究数据表明摇帆能有效提高其空气动力性能,沿帆面展向方向来回转动摇帆时能较好保证航行状态的稳定性,一定转角下沿帆面弦向方向来回转动摇帆采用较大频率时能获得较高的升阻比。本论文较为系统的开展了帆板摇帆的空气动力性能研究,为帆板摇帆的科学化训练打下了理论基础。该研究部分成果在备战2008年北京奥运会期间应用到中国国家帆板队训练、比赛实践中,为我国帆板项目夺得首枚奥运会金牌做出了贡献。本论文研究工作只是对帆板摇帆的简单运动方式进行了初步数值模拟,后续还需对帆板摇帆的实际运动方式进行深入研究。更多还原

【Abstract】 By use of the numerical simulation and experimental method to sail in steady and unsteady state, the aerodynamic performance of sail in women’s level of Olympic Games was studied. The result of the research guided by the Fluid Mechanics and Computational Fluid Dynamics could supervise the athletes to pump sails based on the external condition.Through the numerical calculation on the literature material SAIL1on the steady state, the research first put STAR-CCM+software into use. The calculation results and the test results were fit for the practice that verify the calculation method used in the literature material and the applicability of the STAR-CCM+software. The calculation area of NP sail was a sail with hemline chord length8times to the front, left, right and16times to the back of the benchmark shaping in a cuboid area. It adopted the method of hexahedron core grid that called Trimmed Mesh(Hexahedral) to divide the calculation area and its internal sail. According to the requirement in the actual windsurfer competition, the minimum wind conditions of2m/s and3m/s were elected as the inlet boundary conditions to the steady state of numerical simulation in NP sail. The calculation and comparison were done on NP sail with regard to different wind speed, lift coefficient and coefficient under different angle of attack. It also analyzed the distribution of pressure, the distribution of streamline and the changes of the distribution of velocity in different angle of attack in NP sail.The Unsteady Numerical Simulation of NP sail was based on the pumping state of the athletes, was simplified the needing model study into three mode of motion:1、 the turning direction of the sail around the sail surface;2、the turning direction of the sail around the sail surface string;3、the turning direction of the sail vibrate along the vertical direction. In order to effectively reduce the grid deformation area, to avoid excessive amount of calculation, at the same time, to guarantee the accuracy of numerical calculation, a new area in the internal constructs was built in the unsteady state calculation area. The Unsteady Numerical Simulation was under the direction of rotation movement in different flow to the angle of attack in the NP sail, the data was concluded and analyzed from different angle of attack in the sail through the lift coefficient, drag coefficient and lift-drag ratio of the pumping.According to the maximum lift coefficient and lift-drag ratio in the direction of pumping in the NP sail, the NP sail with amplitude and frequency variation of air power under different movement mode was simulated, thenthe different conditions under the pumping of lift coefficient, drag coefficient and lift/drag ratio were obtained. Based on the simulation results, the change of distribution of surface pressure around the sail surface string and the sail surface were then investigated. The relationship of amplitude and the frequency in different state of the aerodynamic performance in NP sail were then analysed and discussed. The research data showed that pumping can effectively improve the aerodynamic performance through the direction of sail surface in higher frequency shaking was good.This paper carried out a systematic windsurfer sail in aerodynamic performance study that provided a theoretical foundation for the scientific training of windsurfer sail. Some of the research result was applied to the training and the competition of the national windsurfer team for the run-up to the2008Beijing Olympic Games. Fortunately, it made a contribution to the first Olympic gold medal for the windsurfer project in our country. This thesis research worked only on the preliminary numerical simulation of the simple movement mode in pumping of sailboard whereas the subsequent actual movement of pumping should be on the list for the in-depth study.更多还原