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Lift, drag, and cavitation onset on rudders with leading-edge tubercles

Publication ,  Journal Article
Weber, PW; Howle, LE; Murray, MM
Published in: Marine Technology
January 1, 2010

This paper presents the experimental measurement of lift and drag as well as the determination of the onset of cavitation on rudders with leading-edge protuberances (tubercles) that are operating at low to moderate Reynolds Numbers in water. The leading-edge shape used for the rudders in this study is derived from our earlier work concerning the analysis of the leading-edge morphology found on the pectoral flippers of humpback whales. While humpback whales do not swim at speeds that induce cavitation, engineered control surfaces based on this bio-inspired control surface modification might operate in cavitation conditions. This point motivates our present work to investigate the onset of cavitation on small aspect ratio rudders with tubercles. Our findings are that (i) the presence of leading-edge tubercles accelerates the onset of cavitation, (ii) the tubercles can modify the location of the onset of cavitation, (iii) the tubercle geometry has an influence on the rudder's hydrodynamic performance, (iv) for the lower Reynolds Numbers considered in this paper, the tubercles decrease lift and increase drag for angles of attack between 15 and 22 deg, (v) for angles above 22 deg, rudders with tubercles generate more lift than smooth rudders, and (vi) for the higher Reynolds Numbers investigated, the difference in performance between the smooth and tubercled rudders diminishes, suggesting the existence of a critical Reynolds Number for a given tubercle geometry beyond which tubercles have no significant effect on hydrodynamic performance. © Marine Technology.

Duke Scholars

Published In

Marine Technology

ISSN

0025-3316

Publication Date

January 1, 2010

Volume

47

Issue

1

Start / End Page

27 / 36

Related Subject Headings

  • Civil Engineering
 

Citation

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Chicago
ICMJE
MLA
NLM
Weber, P. W., Howle, L. E., & Murray, M. M. (2010). Lift, drag, and cavitation onset on rudders with leading-edge tubercles. Marine Technology, 47(1), 27–36.
Weber, P. W., L. E. Howle, and M. M. Murray. “Lift, drag, and cavitation onset on rudders with leading-edge tubercles.” Marine Technology 47, no. 1 (January 1, 2010): 27–36.
Weber PW, Howle LE, Murray MM. Lift, drag, and cavitation onset on rudders with leading-edge tubercles. Marine Technology. 2010 Jan 1;47(1):27–36.
Weber, P. W., et al. “Lift, drag, and cavitation onset on rudders with leading-edge tubercles.” Marine Technology, vol. 47, no. 1, Jan. 2010, pp. 27–36.
Weber PW, Howle LE, Murray MM. Lift, drag, and cavitation onset on rudders with leading-edge tubercles. Marine Technology. 2010 Jan 1;47(1):27–36.

Published In

Marine Technology

ISSN

0025-3316

Publication Date

January 1, 2010

Volume

47

Issue

1

Start / End Page

27 / 36

Related Subject Headings

  • Civil Engineering