Date

2022-8-12

Author

Karakaş, Hasan Halil

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This study experimentally investigates the flow field around the wings, which first accelerate with constant acceleration from the rest and then perform a linear translating motion with constant velocity. Four wings, which are 3D-printed, with a bending stiffness in different directions are examined. The difference in bending stiffness values is achieved by placing stiffeners having different angles with the leading edge on the upper surface of the wing. The stiffeners are printed with wings to obtain well-integrated wing models. The experiments are conducted in an octagonal water tank and the planar flow fields are obtained using the two-dimensional two-component particle imaging velocity measurement technique (2D2C PIV). PIV measurements show that at the initial phases of motion, a coherent leading-edge vortex is formed for all the wings tested in the experiment and LEV remains stable over a long period of movement. Although the flow fields of vortical structures have similar characteristics for all wings at the beginning of the motion, the vortical structures start to be distinguished from each other after approximately 2.4 chord lengths of travel because of the different deformation characteristics of the wing models. The closest LEV to the wing surface is obtained on the wing without stiffener, which has the maximum camber generation because of its highly chordwise flexibility. The wing with 90° of stiffener produces the highest LEV circulation, whereas the wing without stiffener generates the lowest one. This study shows that the optimum wing structure that offers the best flight performance in terms of aerodynamic efficiency can be manufactured by using 3D printing technology for predefined flapping-wing micro aerial vehicle operations.

Subject Keywords

Particle image velocimetry, Leading edge vortex, Flexible wing, Stiffener, 3D printer, Micro aerial vehicles

URI

https://hdl.handle.net/11511/98746

Collections

Graduate School of Natural and Applied Sciences, Thesis