Canoe Sprints

It also depends on the class of kayak race. For some races the average
speed in 3.5 metre depth water means they are operating close to the
critical depth- based Froude number.
The same with some rowing classes : for the early part of the stroke the
boat is operating sub-critical, during the recovery (when rowers are sliding back
to the stern with oars out of the water) they are in the super-critical
range where wave resistance can be less than that in deep water. A messy but
very interesting problem!

 

Series 64 is one of the banes of my life.
I can get very good agreement with experiments for the hulls I have offsets
for (including the one Martin Renilson used for monhull and cat experiments).
And the US Navy got good results using one of my programs for several
members of the series, but damned if I can get offsets for those hulls in the
format I need.

 

What format do you need them in??... We gave Prof. Molland our hulls (Series 64), physical models and electronic for his series of experiments over the past 2 decades.

 

Ideally, a table of offsets.
If it can be read by Deftship I can always use its export function to create a
Michlet file which I can then convert to Flotilla or other codes.

No hurry. Now that I'm back on the dole I have enormous numbers of research projects to play with

 

What format does Deftship accept?? Ive never used this, thus no idea.

I'll see what formats I have and see what I can do.

Busy finishing of 2 designs right now...but I'll hunt for them in my tea breaks

 

Are you talking about C boats ("canadian canoes", paddler(s) kneeling, single blade paddles) or K boats ("kayaks", paddler(s) sitting, double blade paddles)? The K boats appear to move much more smoothly with considerably less pitching than the C boats. My guess is the speed is also considerably more constant for the K boats than the C boats.

 

How universal is that chart? Does it apply to all hull forms?

 

All hull forms, but in the L/D ratio of 7-8 and higher

 

How broadly applicable are you comments? All hull forms, ones with small B/L typical of shells and racing canoes and kayaks, or ???

 

Any limitations on L/B?

 

Kayaks, David.
I haven't done any work on canoes. They bounce around too much for my liking.

 

I'd say for L/B > about 8 or 10. Definitely for kayaks and rowing shells.

 

Delftship accepts IGES and PolyCad files (whatever they are).
I know very little about these formats.

 

The hulls were typical for the series 64 and the variants (and radically different, like the 'crude' hull), L/B ratios of 15-20.

The limitation is thus governed by maintaining the L/D ratio.

Makes two of us

 

Congratulations to Team GB for winning the mens 200m this morning! That work in the tow tank paid off...