自由度对鱼类自主游动数值模拟结果的影响

Effects of degree of freedom on numerical results of self-propelled fish swimming

采用自适应浸没边界方法,数值模拟了仿生鱼在不同自由度个数情况下的游动,对比分析了自由度个数对仿生鱼受力、能耗、推进效率以及尾涡结构的影响。研究结果表明,推进效率随着自由度个数的增加而略有降低;当仿生鱼在自主游动过程中没有侧向运动速度时,侧向受力幅值会大幅度提高。另外,当采用"六自由度模型"进行模拟时,仿生鱼很难沿直线运动,从而导致定量分析的困难。

Numerical simulations of self-propelled fish swimming with different number of degree of freedom are carried out. The Effects of the number of degree of freedoms on forces, power consumption, propulsive efficiency and vortex structures are investigated. The results show that the propulsive efficiency decreases as the number of degree of freedom increases. The amplitude of the lateral force of the model without lateral motion and rotation is much higher than that of models with lateral movement. In addition,it is difficult to move along a straight line and analyze quantitatively when the virtual swimmer swims using a model with six freedoms.