蝌蚪模型并列游动的数值研究

Numerical investigation of tadpole models swimming in side-by-side arrangement

该文通过数值求解雷诺平均N-S方程,对高雷诺数下蝌蚪模型同相位和反相位并排游动进行了数值研究,揭示了并列蝌蚪群游的流动机制。研究表明,非流线型的蝌蚪并列群游与流线型的鱼体不同。蝌蚪同相位并列游动时,总推力比单独游动时低,尽管能量消耗有所增加但推进效率更高;蝌蚪反相位并列游动时,总推力比单独游动时低,但比同相位并列游动时高,间距很近时消耗的能量会显著增加,而推进效率依然提高。蝌蚪的钝体头部产生的涡在群游时有利于增加推力。

In this article, a numerical simulation of the tadpole-like model school swimming under high Reynolds numberis conductedby solving the two-dimensional incompressible Reynolds-averaged Navier-Stokes （RANS） equations. The flow mechanism of tadpoles＇ swimming in side-by-side arrangement including in-phase and anti-phase patterns was revealed. The study shows that in paralleled school swimming, the performance of non-streamlined tadpole is different to that of streamlined fish. When tadpoles swim in in-phase schooling, total thrust decreases as the distance between tadpoles narrowing, while the energy cost and propulsive efficiency increase significantly. When tadpoles swim in anti-phase pattern,total thrust becomes lower as tadpoles closing to each other, but it＇s higher than the thrust of in-phase pattern. The total power consuming and propulsive efficiency also increase significantly as the distance between tadpoles is very close. In the study, there is a pair of vortices shedding from the blunt head of the tadpole, which can enhance thrust generated by the tadpole tail.