Airfoils ° / apping in pitch and plunge are studied, and the ° / apping motion parameters are op-
timized to maximize thrust generation and the e± / ciency of the thrust generation. Unsteady
viscous ° / ow¯ / elds over ° / apping airfoils are computed on overset grids using a Navier-Stokes
solver. Computations are performed in parallel using Parallel Virtual Machine library routines
in a computer cluster. A single ° / apping airfoil and dual airfoils ° / apping in a biplane con-
¯ / guration are considered. A gradient based optimization algorithm is employed. The thrust
production and the e± / ciency of the thrust production are optimized with respect to ° / apping
parameters / the plunging and pitching amplitudes, the ° / apping frequency, and the phase shift
between the pitch and plunge motions. It is observed that thrust generation of ° / apping airfoils
strongly depends on the phase shift and high thrust values may be obtained at the expense
of reduced e± / ciency. For a high e± / ciency in thrust generation, the e® / ective angle of attack
of the airfoil is reduced and large scale vortex formations at the leading edge are prevented.
At a ¯ / xed reduced ° / apping frequency of 1, a single ° / apping airfoil in pitch and plunge motion produces the maximum average thrust coe± / cient of 1:41 at the plunge amplitude of 1:60, the
pitch amplitude of 23:5o, and the phase shift of 103:4o whereas the maximum e± / ciency of 67:5%
is obtained at the plunge amplitude of 0:83, the pitch amplitude of 35:5o and the phase shift of
86:5o.
| Identifer | oai:union.ndltd.org:METU/oai:etd.lib.metu.edu.tr:http://etd.lib.metu.edu.tr/upload/12612286/index.pdf |
| Date | 01 July 2003 |
| Creators | Kaya, Mustafa |
| Contributors | Tuncer, Ismail H. |
| Publisher | METU |
| Source Sets | Middle East Technical Univ. |
| Language | English |
| Detected Language | English |
| Type | M.S. Thesis |
| Format | text/pdf |
| Rights | To liberate the content for public access |
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