基于CFD技术的动态游泳运动水动力特性分析

Analysis of hydrodynamic characteristics of dynamic swimming based on CFD technology

为了了解和改善游泳动作效率,提出一种基于计算流体动力学(CFD)技术的三维动态游泳数值模拟方法,以海豚泳为例,对游泳的水动力特性进行探讨。遵循人体关节运动规律,提出游泳运动员模型刚体化的假设,建立多体运动游泳数值计算模型,并通过三维不可压缩Navier-Stokes方程结合RNG k-ε湍流模型进行求解,探讨了海豚泳游动过程中的整体与各躯体部位(上肢、胸部、腰部、大腿、小腿、脚掌)的水动力特征。研究结果表明,在海豚泳中,推进力的产生与膝关节伸展运动密切相关;在向上打腿和向下打腿的过程中,脚掌均为主要的推进力来源部位,小腿和大腿的运动,是净阻力的主要来源,腰部上下摆动所做的正功要大于负功。结论可应用于指导游泳运动员入水和转身后海豚泳技术动作的改进。

In order to understand and improve the efficiency of swimming movements,a three-dimensional dynamic swimming numerical simulation method based on computational fluid dynamics(CFD)technology is proposed in this paper,and the hydrodynamic characteristics of swimming are discussed by taking dolphin swimming as an example.Based on the rules of human joint movement,the hypothesis of the rigid body of the swimmer’s model is proposed.On this basis,a multi-body swimming numerical calculation model is established.The three-dimensional incompressible Navier-Stokes equation combined with RNG k-εturbulence model is used for multi-body swimming numerical calculation.The hydrodynamic characteristics of the whole body and the body parts(upper limbs,chest,waist,thighs,calfs and soles)during the swimming process are discussed.The results indicate that in dolphin swimming,the propulsive force is closely related to knee stretching,and that in the process of up kick and down kick,the sole of the foot is the main source of propulsion force,the movement of the calf and thigh is the main source of net resistance,and the waist does more positive work than negative work during the process of swinging up and down.The conclusion of this study can provide guidance for the improvement of dolphin swimming technique after swimmers’entry and turn.