Boundary Layer Control - Skin Friction

[FEAstress]

I'm investigating possible drag reductions for ship hulls and submarines. Is there any data available for skin texture (roughness, etc) effects at various speeds and/or Reynolds numbers, etc?

I've heard that sharks have a matt finish which reduces their total drag quite a bit. Anyone know about this subject?

 

[IRstuff]

Somewhat off topic; there recently, i.e., sometime this year, Scientic American had a fascinating article about using supercavitation as a means of reducing drag for torpedoes. I've also been told that certain anti-mine ammuntion likewise uses supercavitation to get increased penetration depth.

TTFN

 

[arto]

Whoa -wicked cool!!
The article's here & lotsa other good stuff too! [Penn State]

http://www.courses.psu.edu/courseweb/courses/materials.cgi?course=m_e033_mmm124

or just the article from May 01

http://www.sciam.com/article.cfm?articleID=000CA29B-0EA6-1C70-84A9809EC588EF21&pageNumber=1&catID=2

 

[mx2mx2]

I note that this thread is fairly old, but this information may still be usefull. There is an ultra thin coating that can be applied over hull paint that will greatly reduce drag. It is self bonding and non-stick in nature. It can be found at

http://www.kiss-cote.com.

Good luck,

Malcolm