Journal
JOURNAL OF EXPERIMENTAL BIOLOGY
Volume 207, Issue 7, Pages 1063-1072Publisher
COMPANY BIOLOGISTS LTD
DOI: 10.1242/jeb.00848
Keywords
insect flight; Reynolds number; aerodynamics; flow visualization
Categories
Ask authors/readers for more resources
The elevated aerodynamic performance of insects has been attributed in part to the generation and maintenance of a stable region of vorticity known as the leading edge vortex (LEV). One explanation for the stability of the LEV is that spiraling axial flow within the vortex core drains energy into the tip vortex, forming a leading-edge spiral vortex analogous to the flow structure generated by delta wing aircraft. However, whereas spiral flow is a conspicuous feature of flapping wings at Reynolds numbers (Re) of 5000, similar experiments at Re=100 failed to identify a comparable structure. We used a dynamically scaled robot to investigate both the forces and the flows created by a wing undergoing identical motion at Re of similar to120 and similar to1400. In both cases, motion at constant angular velocity and fixed angle of attack generated a stable LEV with no evidence of shedding. At Re=1400, flow visualization indicated an intense narrow region of spanwise flow within the core of the LEV, a feature conspicuously absent at Re=120. The results suggest that the transport of vorticity from the leading edge to the wake that permits prolonged vortex attachment takes different forms at different Re.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available