Aerodynamic Characteristics of a Normal Hovering Foil with Synthetic Jet Actuation
- PDF / 3,033,703 Bytes
- 11 Pages / 595.276 x 841.89 pts (A4) Page_size
- 87 Downloads / 170 Views
Journal of Bionic Engineering http://www.springer.com/journal/42235
Aerodynamic Characteristics of a Normal Hovering Foil with Synthetic Jet Actuation Jie Wu1,2,3*, Lan Jiang2,3, Xingjian Lin2,3 1. State Key Laboratory of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China 2. Department of Aerodynamics, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China 3. Key Laboratory of Unsteady Aerodynamics and Flow Control, Ministry of Industry and Information Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
Abstract The aerodynamic characteristics of a normal hovering foil with Synthetic Jet (SJ) actuation are numerically studied in this work. An elliptic foil with ratio of 4 undergoes the imposed translation and rotation synchronously. A pair of SJs with the same frequency and strength is placed on the upper and lower surfaces of the foil. Thus, the local flow field around the foil would be influenced. At the Reynolds number of 100 and the rotating axis position of half chord, the effects of the inclined angle between the jet direction and the chord line, the phase angle between the SJs and the translation as well as the SJ location on the aerodynamic characteristics are systematically examined. Compared with the oscillating foil without SJ actuation, it is illustrated that the enhancement of mean lift force and hovering efficiency can be obtained by using the SJs with suitable working parameters. Based on the numerical analysis, it is found that the jet flow on the foil surfaces, which changes the local pressure distribution, can benefit the aerodynamic performance of the hovering foil. Keywords: normal hovering foil, translation and rotation, synthetic jet, lift enhancement Copyright © Jilin University 2020.
1 Introduction Attracted by elegant flight and transcendent maneuverability of birds/insects in nature[1–3], studies on flapping wings have persisted for years. Both experiments and numerical simulations have been extensively performed[4–8]. Some important conclusions have been achieved. For example, the stall delay caused by the Leading Edge Vortex (LEV) can significantly improve the lift force, the fast pitching rotation together with wake capture effect also can increase the force, and the flapping wing flight can save aerodynamic power as compared with the steady flight. Besides research on mechanism, a great deal of effort has been made to optimize the propulsion performance of flapping wings, which is one of important issues in flapping flight. For example, the structural flexibility[9,10] and ground effect[11,12] have been utilized to enhance the propulsive efficiency. As another status of flapping wings, on the other hand, the hovering flight has been paid attention gradually in recent years. Wang *Corresponding author: Jie Wu E-mail: [email protected]
and Russell[13] numerically studied the effects of forewing and hindwing interactions on aerodynamic forces and power in hovering dr
Data Loading...
