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Re: Save resistance with optimum hull design
By:Shawn Baker
Date: 6/27/2001, 11:23 am
In Response To: Re: Save weight with materials/methods, not size (Tom)

And your break even point is at 6 knots. Justifiable for a racer, but not for a recreational paddler paddling the same boat.

You'll havemuch less residual resistance at 3 knots, making the difference in frictional resistance more apparent.

It is interesting to me, though, that the frictional resistance between the two designs is so relatively close.

Shawn

: This should probably go to the Design BB, but I checked my calcs last night
: (using Matt Broze's drag prediction spreadsheet based on John Winter's
: method). The differences between the two designs slowly grow as speed
: increases.

: Predictions for 6 knots: 17.5' kayak: 5.29 residual + 5.27 frictional = 10.56
: lb total resistance

: 19' kayak: 4.80 residual + 5.47 frictional = 10.27 lb total resistance

: Not enough difference for the paddler to notice, but would probably
: make a difference over a 20 mile race course.

: -Tom

Messages In This Thread

Guillemot "L" Launch *Pic*
Dave Seales -- 6/24/2001, 11:40 pm
Re: Guillemot "L" Launch
Roger Nuffer -- 6/25/2001, 3:39 pm
Great looking boat/design! *NM*
Bob Deutsch -- 6/25/2001, 2:48 pm
Re: Guillemot "L" Launch
Ben Staley -- 6/25/2001, 10:33 am
Re: Great Job! It's a fun boat *NM*
Shawn Baker -- 6/25/2001, 10:26 am
Nice Job
David Hanson -- 6/25/2001, 9:49 am
Re: Nice Job
Dave Seales -- 6/25/2001, 12:17 pm
Re: Nice Job
David Hanson -- 6/25/2001, 3:41 pm
Re: Nice Job
LeeG -- 6/28/2001, 8:30 pm
how transparent was the dynel
mike allen ---> -- 6/25/2001, 5:32 pm
Fairly clear *Pic*
David Hanson -- 6/26/2001, 9:36 am
Re: how transparent was the dynel
David Hanson -- 6/25/2001, 5:44 pm
Re: Vacuum-Bagging Dynel
Shawn Baker -- 6/25/2001, 4:06 pm
An idea for you
Brian Nystrom -- 6/25/2001, 5:22 pm
Re: An idea for you
Bruce Schultz -- 6/26/2001, 9:51 am
Re: Vacuum-Bagging Dynel
David Hanson -- 6/25/2001, 4:23 pm
Re: Vacuum-Bagging Dynel
Shawn Baker -- 6/25/2001, 4:31 pm
Re: Weights
Shawn Baker -- 6/25/2001, 12:36 pm
Re: Weights...design question
Ben Staley -- 6/25/2001, 1:03 pm
Re: Save weight with materials/methods, not size
Shawn Baker -- 6/25/2001, 4:29 pm
Re: Save weight with materials/methods, not size
Ben Staley -- 6/25/2001, 5:00 pm
Re: Save weight with materials/methods, not size
Tom -- 6/26/2001, 1:41 pm
Re: Save weight with materials/methods, not size
LeeG -- 6/26/2001, 2:40 pm
Re: Save weight with materials/methods, not size
Tom -- 6/27/2001, 9:43 am
Re: Save resistance with optimum hull design
Shawn Baker -- 6/27/2001, 11:23 am
a problem w/ matching resin/glass wt?
mike allen ---> -- 6/25/2001, 6:15 pm
Re: Weights...design question
Shawn Baker -- 6/25/2001, 4:02 pm
Re: Weights...design question
Paul G. Jacobson -- 6/25/2001, 3:59 pm
Re: Weights
Dave Seales -- 6/25/2001, 12:52 pm