Kayak Design Specs and Drag Predictions, A Poll

[Socrates_thinks]

This will be a simple poll.

Note: so as not to unduly influence the poll, I respectfully request that we all simply vote and refrain from comment.

[Socrates_thinks]

This will be a simple poll.

Note: so as not to unduly influence the poll, I respectfully request that we all simply vote and refrain from comment.

[ricksconnected]

river ?
http://www.kayakfishingstuff.com/images/maps/rofl.gif

[LunaSea]

#1 http://www.kayakfishingstuff.com/images/maps/thumbsup.gif
#2 http://www.kayakfishingstuff.com/images/maps/cookoo.gif

Ooops... http://www.kayakfishingstuff.com/images/maps/rofl.gif

[lconn4]

neither is absolutely correct, in my world. http://www.kayakfishingstuff.com/images/maps/rofl.gifhttp://www.kayakfishingstuff.com/images/maps/the_wave.gif http://www.kayakfishingstuff.com/images/maps/rofl.gif

[Socrates_thinks]

I've gotta let you all in on what about 70% of you have already figured out - that for any performance calculations to be accurate, the target and design displacements must match.

Our resident Team Design Mangler didn't have a clue - none of his designs were completed. All three of his designs were overloaded, in one case by over 40 lbs. Accordingly not one of his drag calcuations was correct and his conclusions were completely unreliable.

Just for fun I posed the same questions (based on our mangler's own results)to Mr. Ross Laidy, the creator of Kayak Foundry regarding my analysis and conclusions, who agreed with me. His email answer:

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> Your assumptions are correct - the hydrostatics are computed based on the design displacement. To determine how the kayak trims at the target displacement, move the DWL marker (right hand side of the waterline in the Profile view) up so that the design and target numbers are close. Once the control is selected, you can use the up/down arrows to nudge it if the mouse control is too coarse.

Ross

: I recently designed a 14 foot kayak using Foundry 1.5.1 (complete results below).
: The target displacement is 225 lb, and the design displacement is less, 181.1 lbs.
: My question: I assume all the design specifications are based on the design displacement or weight (181.1 lbs) as are the drag predictions shown.
: My questions: 1. Is my assumption right, that all specs and predictions are based on the design diplacement of 181.1 lbs and not on the target displacement of 225 lb?

: 2. If this kayak were actually built and carried the target load of 225 lb., what would happen? I assume this heavier than design load would result in increased drag and BWL and draft would increase due to the heavier than design load/displacement. Is this assumption correct.

: And last: 3. If I wanted to determine just how the target load of 225 would act on this design, ie to determine the higher waterline and changed specs, esp. BWL, draft and wetted surface, how would I go about this?

: Thanks...
</div></BLOCKQUOTE>

I rest my case, cause if you think I'm gonna argue with fools, I made that mistake once. Fergit it!

Bottom line:

[RiverRaider]

Capt' Jimbo!!!!!

You have returned at long last, how have you been ole' chum. Where have you been keeping yourself?

Nice piece with Spike by the way, you should re-post it here, or link to it.

Nice to have you back!

**********************EDIT*******************

Oh well Jimbo, so much for me taking the HighRoad with ya'

[RiverRaider]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Our resident Team Design Mangler didn't have a clue - none of his designs were completed. All three of his designs were overloaded, in one case by over 40 lbs. Accordingly not one of his drag calcuations was correct and his conclusions were completely unreliable. </div></BLOCKQUOTE>

Jimbo as hard as you try to make it otherwise... you just cant change what I wrote waaaaay back in November:

"...Notice that these mythical kayaks presented above are all identical in design, the only initial variable changed is legth... Beam is static, draft.. weights etc.. capacities, volumes etc.. change of course accordingly."


Ya' see... Its still there.. unedited just like it has been all this time.

See I used the word "initial" that was the input, see how I said that there would be changes.. that was the output.

The drag calculations were ineed correct, yes Jimbo, they were correct... have you been able to fiqure out why?



Fiqure out the difference between valid and reliable... its a clue in there...

Now, thus far Iv'e had to help you along with understanding the scaling function of Kayak Foundry, Ive had to explain the LittleWings design to you, and Ive tried to help you with your manners. Its alot of work being your friend Jimbo.

Okay Jimbo... deep, cleansing, breaths... kick the dog, yell at the neighbors kid.. go fishing or something, just relax.

When you have calmed down, post the file for the LittleWing clone you used to "extrapolate" your numbers from... many of us have been waitng patiently for some time now, you will feel vindicated.

[ricksconnected]

http://www.kayakfishingstuff.com/images/maps/rofl.gif

[CPP]

I just love when River and the Captn show that much affection for each other. http://www.kayakfishingstuff.com/images/maps/grouphug.gif