Aeroelastic optimization of thin flapping structure
Author(s)
Goon, Grace Swee See
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Other Contributors
Massachusetts Institute of Technology. Department of Aeronautics and Astronautics.
Advisor
Pedro M. Reis.
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We study the flow generated when a handheld fan is waved. This fluid-structure interaction problem is investigated through precision experiments, using an oscillating semi-circular elastic plate as a reduced analog model. The aerodynamic performance of the fans is systematically characterized for a variety of geometric and material parameters, as well as the amplitude of the periodic driving. We demonstrate that the bending stiffness of the structure can be tuned to maximize the output of the generated airflow, while simultaneously minimizing the input power. A design guideline is established for this optimal conditions based on matching the driving and the natural frequencies of the plate. Closer to the handheld fans, we then consider a discrete analog model comprising an array of overlapping strips. Unlike homogeneous plates, these discrete designs deform passively into shapes with finite Gaussian curvature and further enhance the generated flow. Finally, we explored the effect of corrugation on the flapping plate and found that the fan employs the interesting mechanism of reversible buckling to simultaneously increase the velocity of the flow and reduce the load.
Description
Thesis: S.M., Massachusetts Institute of Technology, Department of Aeronautics and Astronautics, 2017. Cataloged from PDF version of thesis. Includes bibliographical references (pages 105-110).
Date issued
2017Department
Massachusetts Institute of Technology. Department of Aeronautics and AstronauticsPublisher
Massachusetts Institute of Technology
Keywords
Aeronautics and Astronautics.