PROPOSAL NO.: CTS-0630489 PRINCIPAL INVESTIGATORS: AMY W. LANG INSTITUTION: UNIVERSITY OF ALABAMA- TUSCALOOSA

SGER: A Biomimetic Surface Roughness Geometry for Boundary Layer Control

This grant will support exploratory, experimental research to investigate the boundary layer flow over a biomimetic roughness geometry. The surface mimics the formation of a roughness micro geometry that can be observed on the skin of fast swimming sharks, conjectured by scientists to have the capability of bristling their denticles (scales) when in pursuit of prey at increased swimming speeds. It is hypothesized that such a surface geometry may lead to the formation of a three-dimensional array of cavity vortices forming between the denticles, and thus a complex partial slip condition over the surface may result strongly affecting the transition to turbulence in the boundary layer. Depending on the Reynolds number of the flow (based on the cavity height or size of the denticle) and the thickness of the boundary layer, the result could be either skin friction reduction or enhancement at the surface. Results from this study may give insight as to why fast sharks, such as the Shortfin Mako (Isurus Oxyrinchus) believed to achieve speeds upwards of 60 mph, have smaller denticles than slower shark species. Another implication is that sharks with larger denticles may not be able to achieve higher speeds due to a sudden increase in drag when attempting to swim past a certain speed. The intellectual merit of the project lies in the potential understanding and application of a means by which nature has already worked out a solution for the reduction of skin friction over a solid surface, resulting in the control of boundary layer flows and their transition to turbulence. Not only would this new method of boundary layer control be discovered, leading to new technological innovations resulting in energy conservation, but also the implications regarding a greater understanding of the biology and evolutionary development of sharks would be significant. The broader impacts of this method of flow control include: drag reduction (e.g. reduction in fuel requirements and/or increased range for aircraft, ships, submarines, etc.), separation control, and mixing and heat transfer enhancement (e.g. cooling of compute hardware components). Other outcomes will include the training of undergraduate and graduate students, with the goal of encouraging the participation of underrepresented groups. Finally, such a discovery would also lend itself well to incorporation into K-12 outreach programs that encourage the pursuit of careers in science and engineering.

Project Start
Project End
Budget Start
2006-07-01
Budget End
2007-12-31
Support Year
Fiscal Year
2006
Total Cost
$58,499
Indirect Cost
Name
University of Alabama Tuscaloosa
Department
Type
DUNS #
City
Tuscaloosa
State
AL
Country
United States
Zip Code
35487