Leading Edge Serrations on Flat Plates at Low Reynolds Number

Document Type

Conference Paper

Publication Date

1-2012

Publication Source

50th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition

Abstract

This study determines the utility of abstractions of wing leading edge features observed across the natural world when operated at low Reynolds numbers and at low aspect ratio. Flat plates are some of the most well understood aerodynamic shapes and thus provide a good baseline case from which to build an understanding of the effects of leading edge serrations. Thus an aspect ratio 2 thin flat plate is tested first in pure rectangular planform and subsequently across a range of leading edge serration densities. Forces are recorded across a range of Reynolds number from 140,000 to 210,000 and smoke flow visualization is also performed. Ultimately, the serrations were found to present little benefit at low angles of attack, however showed potential promise at higher Re numbers. The small serrations at low angles of attack showed the greatest increase in lift coefficient. The medium serrations showed little difference from the flat plate at all angles of attack. The large serrations showed a decrease in lift and increase in drag coefficients at all angles of attack, yet still demonstrated the best stall angle performance.

Pre-stall lift departures on the lift curve observed by others were also observed for the large serrations. Trailing edge serrations resulted in promoting much earlier stall implying that the same mechanism responsible for extending stall when serrations are placed on the leading edge, have the opposite effect on the trailing edge.

ISBN/ISSN

978-1-60086-936-5

Comments

Permission documentation is on file.

Publisher

American Institute of Aeronautics and Astronautics

Place of Publication

Nashville, TN

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