摘要
目的:探讨环境风对跳台滑雪空中飞行气动特性的影响。方法:通过计算流体力学(computational fluid dynamics,CFD)方法数值模拟预测了不同环境风下跳台滑雪空中飞行空气动力学特性,并探究了水平方向环境风、竖直方向环境风以及侧向环境风对气动特性的影响。将跳台滑雪运动员与滑雪板看成一个多体系统,建立在空中飞行某一种普遍姿态下此多体系统的精细化三维几何模型与网格模型,采用部分时均(partially averaged Navier-Stokes,PANS)湍流模型进行数值模拟,提取多体系统的受力及力矩情况,直观地显示多体系统周围的流场信息。数值预测涉及的水平方向风风速包括-4 m/s、-2.5 m/s、-1 m/s、0 m/s、1 m/s、2.5 m/s、4 m/s等工况;竖直方向风风速包括-8 m/s、-4 m/s、-2.5 m/s、-1 m/s、0 m/s、1 m/s、2.5 m/s、4 m/s、8 m/s等工况;侧向风风速包括1.5 m/s、3.0 m/s、4.5 m/s、7.5 m/s、10.5 m/s、13.5 m/s等工况。结果:1)水平方向环境风下多体系统升力、阻力以及俯仰力矩变化明显,与风速呈现近似线性关系,同时水平逆风情况下力学特性数值结果的增长速度大于水平顺风情况下力学特性数值结果的减小速度;2)在竖直方向风速较小时(小于2.5 m/s),升力、阻力以及俯仰力矩增加缓慢,在竖直方向风速较大时(大于4 m/s),升力、阻力以及俯仰力矩开始相对快速增加,同时,竖直向上环境风使得升力、阻力、俯仰力矩增大,竖直向下环境风使得升力、阻力以及俯仰力矩减小,而且竖直向上环境风情况下增长幅度明显小于竖直向下环境风情况下减少幅度;3)侧向环境风产生偏航力、偏航力矩、翻滚力矩,同时,侧向环境风对运动员的升力、阻力以及俯仰力矩产生影响。在风速较小(小于3 m/s)时,这些力和力矩很小,在风速较大(大于4.5 m/s)时,比较明显。结论:1)水平方向环境风对跳台滑雪空中飞行气动特性的影响非常明显,相较而言,竖直方向环境风和侧向环境风对空中飞行气动特性的影响小很多,但侧向环境风的影响情况较为复杂,对多体系统产生较为明显的偏航力、偏航力矩、翻滚力矩;2)环境风对跳台滑雪空中飞行气动特性的影响机理能够为比赛临场预判与决策提供有效的辅助支持,也为运动员空中飞行稳定性控制与技术训练提供科学指导。
Objective:To determine the effects of wind on the aerodynamic characteristics during flight in ski jumping.Methods:Numerical simulation of computational fluid dynamics(CFD)was used to predict the aerodynamic characteristics during flight under different environmental wind,and the effects of horizontal wind,vertical wind and lateral wind on the aerodynamic characteristics were investigated as well.The athlete and skis were regarded as a multi-body system,and partially averaged Navier-Stokes(PANS)turbulence model was used to simulate aerodynamic characteristics of the system based on a general flight attitude,and then the forces,torques and flow field form data were obtained.The horizontal wind speed includes-4 m/s,-2.5 m/s,-1 m/s,0 m/s,1 m/s,2.5 m/s and 4 m/s,the vertical wind speed includes-8 m/s,-4 m/s,-2.5 m/s,-1 m/s,0 m/s,1 m/s,2.5 m/s,4 m/s and 8 m/s,and the lateral wind speed involved includes 1.5 m/,3.0 m/s,4.5 m/s,7.5 m/s,10.5 m/s and 13.5 m/s.Results:1)The lift,drag and pitch torque of the multi-body system under horizontal wind were changed significantly,and the correlations of lift,drag and pitch torque with wind speed were approximately linear.At the same time,the growth rate of mechanical properties under horizontal upwind was higher than that of mechanical properties under horizontal downwind.2)When vertical wind speed was less than 2.5 m/s,the lift,drag and pitch torque increase slowly,but when vertical wind speed was greater than 4m/s,they began to increase relatively rapidly.In addition,vertical upward wind caused the lift,drag and pitch torque to increase,and vertical downward wind caused them to decrease.Moreover,increase rate was obviously smaller than decrease rate.3)Lateral wind produced yaw force,yaw torque and rolling torque,and had an impact on the lift,drag and pitch torque of the athletes.When the wind speed was less than 3 m/s,these forces and torques were very small,and when the wind speed was larger than 4.5 m/s,they were more obvious.Conclusion:1)The influence of horizontal wind on the aerodynamic characteristics during flight in ski jumping is very significant.In contrast,vertical wind and lateral wind have much less influence,but the influence of lateral wind is more complicated,which causes yaw force,yaw torque and rolling torque obviously to the multi-body system.2)The influence mechanism of wind on the aerodynamic characteristics during flight in ski jumping can provide effective auxiliary support for on-the-spot prediction and decision-making,and also provide scientific guidance for flight stability control and technical training for athletes.
作者
胡齐
刘宇
HU Qi;LIU Yu(China Institute of Sport Science,Beijing 100061,China;Dean of School of Kinesiology,Shanghai University of Sport,Shanghai 200438,China)
出处
《体育科学》
CSSCI
北大核心
2020年第3期54-63,共10页
China Sport Science
基金
国家自然科学基金项目(11802068)
国家重点研发计划项目(2019YFF0302000)
国家体育总局体育科学研究所基本科研业务费资助项目(基本19-06)。
关键词
气动特性
跳台滑雪空中飞行
环境风
计算流体力学
飞行稳定性
aerodynamic characteristics
flight phase in ski-jumping
wind
computational fluid dynamics
flight stability
