The Kayak Forum is Sponsored By
|
|
|
| |
Kayak and Canoe Design Bulletin Board
Re: Ever faster, by a decimal
Posted By: Pete W. P.
Date: Sunday, 28 November 1999, at 4:38 p.m.
> Myth.
> For turbulance initiators (seams or ridges) to reduce drag they must cause
> the transition from laminar to turblant flow. These do not, therefore any
> reduction in drag is caused by some other factor.> As a note: As early as 1970, I used to run and bicycle with the seams of
> my clothes on the outside for comfort reasons.Fact.
My rebuttal is as good as my information which I truly believe was reputable and highly accurate. Wish I could find the damned issue now!! Incidentally, tho I referred to them as "seams" they werent infact seams at all. The ripples literaly "outlined" the cyclists profile. As if you drew a line around a standing figure - thats were the line encircled the uniform. Turning ones shirt inside out isnt a comparable example. The folks who claimed success with this werent dreaming it up. Tho I believe the results outside of a time trial are probably unoticed, they are infact real. The isssue of the oncoming air needing to be laminar and in turn made turbulent... well thats a little nebulous. Laminar air is generally a relative term by way of contrast to turbulent air. Absolute laminar air flow doesnt exist outside of theory, however so long as the difference between the two airflows is great enough you dont need "absolutes". As far as turbulence initiators needing to turn laminar airflow into turbulence, and you r claim that the said ridges dont, is just plain wrong.
Pete
| |
Kayak and Canoe Design Bulletin Board is maintained by Nick Schade - Guillemot Kayaks with WebBBS 5.12.
|
Boat Design |
|
|
|
