Department of Applied Mechanics and Engineering, School of Engineering, Sun Yat-sen University, Guangzhou, 50275, China.
Sci Rep. 2017 Mar 24;7(1):406. doi: 10.1038/s41598-017-00399-y.
The hydrodynamic performance of the locomotive near the water surface is impacted by its geometrical shape. For marine animals, their geometrical shape is naturally selective; thus, investigating gliding locomotion of marine animal under the water surface may be able to elucidate the influence of the geometrical shape. We investigate three marine animals with specific geometries: the killer whale is fusiform shaped; the manta ray is flat and broad-winged; and the swordfish is best streamlined. The numerical results are validated by the measured drag coefficients of the manta ray model in a towing tank. The friction drag of the three target models are very similar; the body shape affected form drag coefficient is order as swordfish < killer whale < manta ray; the induced wave breaking upon the body of the manta ray performs different to killer whale and swordfish. These bio-inspired observations provide a new and in-depth understanding of the shape effects on the hydrodynamic performances near the free surface.
水面附近的船体水动力性能受到其几何形状的影响。对于海洋动物，它们的几何形状是自然选择的；因此，研究海洋动物在水面下的滑行运动，可能有助于阐明几何形状的影响。我们研究了三种具有特定几何形状的海洋动物：虎鲸呈梭形；蝠鲼呈扁平宽翼状；剑鱼则是最流线型的。通过在拖曳水池中测量蝠鲼模型的阻力系数对数值结果进行了验证。三个目标模型的摩擦阻力非常相似；体型对形状阻力系数的影响顺序为剑鱼<虎鲸<蝠鲼；蝠鲼身上的诱导波破碎方式与虎鲸和剑鱼不同。这些受生物启发的观察结果为深入了解自由表面附近的水动力性能对形状的影响提供了新的认识。
