Shahrood University of Technology Journal of Solid and Fluid Mechanics 2251-9475 14 4 2024 09 22 Investigating the Influence of Maximum Camber, Amplitude and Frequency of Oscillation on the Hysteresis Characteristics of an Oscillating Airfoil Investigating the Influence of Maximum Camber, Amplitude and Frequency of Oscillation on the Hysteresis Characteristics of an Oscillating Airfoil 53 71 3320 10.22044/jsfm.2024.14269.3848 FA Mohammad Haji Jafari Department of Industrial, Mechanical and Aerospace Engineering, Buein Zahra Technical University, Qazvin, Iran Javad Chavoshi Komar Olia Mechanical Engineering Department, Elm o Sanat University, Tehran, Iran 0009-0000-7194-1244 Journal Article 2024 04 05 In this research, the dynamic behavior of an oscillating airfoil is investigated (around a.c.) to showcase the influence of geometrical and cyclic parameters (i.e. the maximum camber, amplitude and frequency of oscillation). Hence, airfoils NACA0012, 1412, 2412, 3412 and 4412 are analyzed for the oscillation amplitude of 10° and frequency of 2.5 Hz. Assuming an amplitude of 10° for NACA4412, this is repeated to evaluate the effect of the oscillation amplitude, and for frequencies of 1, 2.5 and 4 Hz to study the effect of oscillation frequency. More than the characteristics related to the overall shape of graphs (depicting lift, drag, and pitching moment coefficients vs angular velocity and angle of attack), such as the direction of rotation, twist and deformity, the area enclosed in the hysteresis loops matters which allows analyzing the transmitted power or wasted energy. While the deformity is generally caused by the flow separation on the upper surface of the airfoil, the twist of the loops can be caused by the out-of-the-phase movement of the airfoil regarding the flow. It can be seen that more the airfoil is cambered, the better the lift coefficient while strongly changing the drag and pitching moment coefficients. In this research, the dynamic behavior of an oscillating airfoil is investigated (around a.c.) to showcase the influence of geometrical and cyclic parameters (i.e. the maximum camber, amplitude and frequency of oscillation). Hence, airfoils NACA0012, 1412, 2412, 3412 and 4412 are analyzed for the oscillation amplitude of 10° and frequency of 2.5 Hz. Assuming an amplitude of 10° for NACA4412, this is repeated to evaluate the effect of the oscillation amplitude, and for frequencies of 1, 2.5 and 4 Hz to study the effect of oscillation frequency. More than the characteristics related to the overall shape of graphs (depicting lift, drag, and pitching moment coefficients vs angular velocity and angle of attack), such as the direction of rotation, twist and deformity, the area enclosed in the hysteresis loops matters which allows analyzing the transmitted power or wasted energy. While the deformity is generally caused by the flow separation on the upper surface of the airfoil, the twist of the loops can be caused by the out-of-the-phase movement of the airfoil regarding the flow. It can be seen that more the airfoil is cambered, the better the lift coefficient while strongly changing the drag and pitching moment coefficients. https://jsfm.shahroodut.ac.ir/article_3320_2ea6177bbf9986f50507bee756f0a59e.pdf