2006/08/16 by Jung-Sang Lee, Chongam Kim, Kyu Hong Kim · 44 citations
Engineering · #Aerodynamics #Aeronautics #Aerospace #Aerospace Engineering and Energy Systems #Aerospace engineering #Airfoil #Biomimetic flight and propulsion mechanisms #Computational fluid dynamics #Engineering #Fluid Dynamics and Turbulent Flows #Marine engineering #Mechanics #Physics #Reynolds number #Turbulence
paper · doi:10.2514/1.15981
published in AIAA Journal 44(9), 1960-1972 (American Institute of Aeronautics and Astronautics)
openalex publication_date 2006/08/16 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/02
Unsteady, viscous, incompressible flows over an airfoil under flapping motion are numerically investigated. Depending on key parameters such as Reynolds number, reduced frequency, and flapping amplitudes, a flapping airfoil could experience complex flow fields. The trailing-edge vortex plays an important role to induce inverse Kármán-vortex street which is a jetlike flow on the downstream and then generates thrust. And, the leading-edge separation vortex is closely related on the propulsive efficiency. Through careful computations of several pitching, plunging, and plunging combined with pitching modes in terms of flow and/or geometry parameters, the key physical flow phenomenon dictating the aerodynamic characteristics of flapping airfoil is identified. Based on the analysis of thrust coefficient and propulsive efficiency a new airfoil shape for optimal aerodynamic performance is proposed. The improved performance of the new flapping airfoil is validated in terms of thrust coefficient and propulsive efficiency in various low-Reynolds number flow regimes.