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Unsteady aerodynamic force generation by a model fruit fly wing in flapping motion
- Source :
- Journal of Experimental Biology. 205:55-70
- Publication Year :
- 2002
- Publisher :
- The Company of Biologists, 2002.
-
Abstract
- SUMMARY A computational fluid-dynamic analysis was conducted to study the unsteady aerodynamics of a model fruit fly wing. The wing performs an idealized flapping motion that emulates the wing motion of a fruit fly in normal hovering flight. The Navier–Stokes equations are solved numerically. The solution provides the flow and pressure fields, from which the aerodynamic forces and vorticity wake structure are obtained. Insights into the unsteady aerodynamic force generation process are gained from the force and flow-structure information. Considerable lift can be produced when the majority of the wing rotation is conducted near the end of a stroke or wing rotation precedes stroke reversal (rotation advanced), and the mean lift coefficient can be more than twice the quasi-steady value. Three mechanisms are responsible for the large lift: the rapid acceleration of the wing at the beginning of a stroke, the absence of stall during the stroke and the fast pitching-up rotation of the wing near the end of the stroke. When half the wing rotation is conducted near the end of a stroke and half at the beginning of the next stroke (symmetrical rotation), the lift at the beginning and near the end of a stroke becomes smaller because the effects of the first and third mechanisms above are reduced. The mean lift coefficient is smaller than that of the rotation-advanced case, but is still 80 % larger than the quasi-steady value. When the majority of the rotation is delayed until the beginning of the next stroke (rotation delayed), the lift at the beginning and near the end of a stroke becomes very small or even negative because the effect of the first mechanism above is cancelled and the third mechanism does not apply in this case. The mean lift coefficient is much smaller than in the other two cases.
- Subjects :
- Lift coefficient
Rotation
Physiology
Movement
Aquatic Science
Models, Biological
Animals
Wings, Animal
Computer Simulation
Wing loading
Molecular Biology
Ecology, Evolution, Behavior and Systematics
Mathematics
Wing
Stall (fluid mechanics)
Aerodynamics
Mechanics
Biomechanical Phenomena
Aerodynamic force
Flight, Animal
Insect Science
Wingtip vortices
Flapping
Drosophila
Animal Science and Zoology
Subjects
Details
- ISSN :
- 14779145 and 00220949
- Volume :
- 205
- Database :
- OpenAIRE
- Journal :
- Journal of Experimental Biology
- Accession number :
- edsair.doi.dedup.....9ca1ba4be52c20cb8ef62f797584384d