环境风对跳台滑雪空中飞行气动特性的影响

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...

Effects ofWind on the Aerodynamic Characteristics during Flight in Ski Jumping

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.