Pesavento Umberto, Wang Z Jane
Department of Theoretical and Applied Mechanics, Cornell University, Ithaca, New York 14853, USA.
Phys Rev Lett. 2009 Sep 11;103(11):118102. doi: 10.1103/PhysRevLett.103.118102.
Flapping flight is more maneuverable than steady flight. It is debated whether this advantage is necessarily accompanied by a trade-off in the flight efficiency. Here we ask if any flapping motion exists that is aerodynamically more efficient than the optimal steady motion. We solve the Navier-Stokes equation governing the fluid dynamics around a 2D flapping wing, and determine the minimal aerodynamic power needed to support a specified weight. While most flapping wing motions are more costly than the optimal steady wing motion, we find that optimized flapping wing motions can save up to 27% of the aerodynamic power required by the optimal steady flight. We explain the cause of this energetic advantage.
扑翼飞行比稳定飞行更具机动性。这种优势是否必然伴随着飞行效率的权衡，目前尚无定论。在此，我们探讨是否存在比最优稳定运动在空气动力学上更高效的扑翼运动。我们求解了二维扑翼周围流体动力学的纳维-斯托克斯方程，并确定了支撑特定重量所需的最小空气动力学功率。虽然大多数扑翼运动比最优稳定翼运动成本更高，但我们发现优化后的扑翼运动可节省高达27%的最优稳定飞行所需的空气动力学功率。我们解释了这种能量优势的成因。
