Kinematics, hydrodynamics and energetic advantages of burst-and-coast swimming of koi carps (Cyprinus carpio koi)
Kinematics, hydrodynamics and energetic advantages of burst-and-coast swimming of koi carps (Cyprinus carpio koi)
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DOI：
10.1242/jeb.001842
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发表时间：
2007-06
影响因子：
2.8
通讯作者：
Guanhao Wu;Yan Yang;L. Zeng
中科院分区：
文献类型：
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作者：
Guanhao Wu;Yan Yang;L. Zeng
锦鲤经常以爆发和海岸的方式游泳，包括爆发阶段和海岸阶段。我们对鲤鱼在突击和海岸游泳中产生的游泳运动学和流型进行了量化。在猝发阶段，鲤鱼以两种模式爆发：第一种模式，尾巴至少跳动一个周期(多个尾拍模式)；第二种模式，尾巴仅跳动半个周期(半个尾拍模式)。鲤鱼在每个半周期节拍中产生一个涡环。在多个尾拍模式下爆发时产生的涡环形成一个链条，而在半尾拍模式下只产生一个涡环。尾迹形态，如动量角和喷流角，在两种模式下也有很大的不同。在猝发阶段，将运动学数据和从尾迹获得的冲量联系起来，得到阻力系数(CD，Burst≈0.242)。在海岸段，阻力系数(Cd，海岸≈0.060)是根据游泳速度减速估算的。我们的估计表明，与以相同的平均速度稳定游泳相比，锦鲤采用突发性和海岸式游泳可以节省近45%的能量。
SUMMARY Koi carps frequently swim in burst-and-coast style, which consists of a burst phase and a coast phase. We quantify the swimming kinematics and the flow patterns generated by the carps in burst-and-coast swimming. In the burst phase, the carps burst in two modes: in the first, the tail beats for at least one cycle (multiple tail-beat mode); in the second, the tail beats for only a half-cycle (half tail-beat mode). The carp generates a vortex ring in each half-cycle beat. The vortex rings generated during bursting in multiple tail-beat mode form a linked chain, but only one vortex ring is generated in half tail-beat mode. The wake morphologies, such as momentum angle and jet angle, also show much difference between the two modes. In the burst phase, the kinematic data and the impulse obtained from the wake are linked to obtain the drag coefficient (Cd,burst≈0.242). In the coast phase, drag coefficient (Cd,coast≈0.060) is estimated from swimming speed deceleration. Our estimation suggests that nearly 45% of energy is saved when burst-and-coast swimming is used by the koi carps compared with steady swimming at the same mean speed.