UNSTEADY AERODYNAMICS OF CAMBERED AIRFOILS AT LOW REYNOLDS NUMBER

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2022-2

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AHMED, TAWFIQ

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Almost all the insects and birds fly at very low Reynolds numbers. Therefore, to design micro air vehicles (MAVs), a study of airfoils and wings at low Reynolds numbers is essential. Unsteady flow behavior at low Reynolds numbers can vary for different airfoils depending on their camber, maximum thickness, or maximum camber position. Numerical simulations of cambered airfoils (NACA 1412, NACA 2412, NACA 3412, NACA 4412) at Re = 1000 are conducted in the current study to understand the camber effect on the unsteady aerodynamic behavior at a low Reynolds number. The numerical simulations are performed at angles of attack ranging from 0° to 10° with an increment of 1°. A domain with a C-type shape for upstream flow and a rectangular shape for downstream flow is prepared for meshing. Meshes are generated using both a structured grid in the outer region and an unstructured grid in the inner region. Thick boundary layers are implemented around airfoils as at low Reynolds numbers boundary layer gets thicker. The aerodynamic coefficients, pressure distributions, flow separations, and wake flow fields are analyzed from the simulations in detail in the two-dimensional domain. The airfoil producing the highest lift is then simulated in the three-dimensional domain to compare the data with the 2D simulation. In each chapter, the effects of camber are discussed with results.

Subject Keywords

Flapping Wing, Unsteady Aerodynamics, Micro Air Vehicles, Low Reynolds Number, Computational Fluid Dynamics, Cambered Airfoils

URI

https://hdl.handle.net/11511/96363

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Graduate School of Natural and Applied Sciences, Thesis

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Citation Formats

T. AHMED, “UNSTEADY AERODYNAMICS OF CAMBERED AIRFOILS AT LOW REYNOLDS NUMBER,” M.S. - Master of Science, Middle East Technical University, 2022.