Aeroelastic optimization of thin flapping structure

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.

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Aeronautics and Astronautics.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2017

Author dc:creator

• Goon, Grace Swee See

Advisor dc:contributor.advisor

• Pedro M. Reis.

• Aeronautics and Astronautics.

Statement dc:rights

• MIT theses are protected by copyright. They may be viewed, downloaded, or printed from this source but further reproduction or distribution in any format is prohibited without written permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/112462

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/112462