Coanda Channel Technology

Oh wow that smoothed out rendering looks good. Stoneburner I have a question. Is there tail rocker present at the rail in the tail or does that line effectively project straight from around mid board?
If so I’m guessing that when turning on rail the submerged half of the channel acts like a fin with the curve of the channel assisting the turning of the tail?
Would/could this be run as a twin or maybe a single fin in the centre of the channel?
It looks really interesting!

As always Jim, “Impressive. Most impressive.”

Railway,

The rail and bottom (outside the channel) are flat from widepoint to tail end. The channel actually acts as an augmented tail rocker and finless fin. Yes, when turning, “in theory,” submerging only one of the channel’s sidewall curves has foil effects that augment and push the board into the turn.

The low drag of the channel design makes it a benefit for finless. I can see adding 1 or more fins. I see it most as a twin, with fin placement a bit different from a standard twin set up because a single channel has a center fin-like effect.

It’s a really interesting concept! I guess something like the Lovelace FM is a subtle version of the same thing to a degree? FM – LOVEMACHINE SURFBOARDS
Although the channel bottom is totally different so maybe not even in the same ballpark?!
I can kind of imagine some small sidebite type fins running as a twin or a small twinzer setup looking good on that tail. Maybe 1/2 way up the channel?

It’s all about channel curve and channel bottom shapes, depth, width, length, dimensions and ratios. The Lovelace bottom pretty much eliminates most of the Coanda Effect.

I would say the Lovelace “channel wall(?)” has pretty much zero foil effect in turns.

Do you know when Lovelace created the FM Lovemachine?

Forgot to mention, rocker curve in the tail also pretty much neutralizes the hydrodynamic function of the channel.

There’s a pretty good explanation of his design philosophy here
https://www.rlovelace.com/pagefm
His Lovemachine series is later, they are machine shapes of his handshaped designs. Quite a clever business model.

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Thanks Railway. Found that web page before my last post.
Looks like we both began development of our concepts in Spring of 2019.

Because I was sure I was onto something very unique, I filed my first patent application in Oct. 2019 to document my technology. Didn’t want to get snaked by the big board manufacturers.

I went straight to machine shaping to get the precision generated by my curve equations.

I’ve just gone back in the thread and realised I’d missed some posts (or not remembered them!) that answered my questions. I wonder if Marc has shaped a board yet?
Also I see you have a diagram of the channel on a traditional board tail design. Could you effectively retro fit some blocks of foam to an existing board using the existing tail rocker as the base of the channel?
It’s a really interesting design, I’d be really keen on seeing someone do a fish or similar and see it being ridden. I’d love to shape a board utilising this design one day but probably not a good design for someone inexperienced like me to shape early on!

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If you can keep the board bottom flat from wide point to channel exit and the surfboard’s existing tail rocker is steep enough to create a decent channel depth, that should be possible.

I’m liking this as the rail profile at the wide point of this Modified Fish.

Getting close now. Images from Shape3D.

Rail profile at wide point.

Wow!

Two (2) more West Coast CNC shapers/board builders just bailed on me. This was after about a week to 2 weeks of email exchanges and CAD files sent.

I have been re-designing this board with the input of 3 other people, on the fly, non-stop, for the past 6 days. Did this to get these 2 companies the CAD file format they said they needed — including rail shape.

Must be nice to be so succesful that you don’t need business/money.

And Custom builders wonder why there is a community of DIY builders and designers like those here at Sways.

I can shape it fairly well. And I know how it needs to be glassed.
I’ll just have to muddle through with my mediocre epoxy skills and build something passable/rideable.

Onward Thru the Fog…

That is unfortunate. Looking forward to seeing this one built, I don’t think it’s too far out of reach.

Keep on Truckin’!

image from www.singulart.com/blog/wp-content/uploads/2024/02/Keep-on-Truckin-1536x918.jpg

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Fight the good fight, i also want to see that board build, and furthermore maybe One day the stand up version with fins???
Who knows.
Cheers and good waves.

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I’m keen to see something shaped and a ride report as well. I think it’s a really interesting concept.

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Thanks for all of the support gents.
@Arlow,
While my plan is to use it as a paddle-in prone rider, the objective is just as much stand-up finless — a new type of ride.
But as I discussed with Railway, fins could definitely be added — new fin layout set-ups/positions would likely be needed.

I have a winner.
I like this rail profile that merges seamlessly with the deck at the widepoint much better.

Once again, Jim (jrandy) has worked his CAD magic with my data.
Blue lines are my 100% Experimental, equation generated nose rocker curves.
Red lines are Retro Fish based nose rocker curves.


Click image to enlarge.

Jrandy’s latest CAD 3D creations.
Very cool. (Click on image to enlarge.)
Love the glossy orange effect.