FTR If an “individual” wants to build my patented Coanda Channel technology for “personal use,” more power to him/her. But for profit (commercial production), I would have a problem with that.
I patented my channel technology to keep surfboard/kneeboard/bodyboard companies from using my ideas for their profit. I designed the channel with the principles of the Coanda Effect — observed and documented by Henri Coanda (1910 and 1934-1936). The curve equations I generated were based on fluid mechanics designs.
It is not unreasonable to want protection from people who seek to “profit” from my ideas (intellectual property).
This Mike Daniel channel from 1990 inspired me. And eventually, I discovered the Coanda Effect. (Mike and the Bing Auga got close but missed the next level of evolution.)
Twin Coanda Channels:
Closing in on the final shaping files.
(Mislabeled; Front = Side & Right = Rear)
~ Again, jrandy (Jim) has transformed my data into visual images ~
The recessed channel is low drag. The wall curves create counter-vortices that minimize disturbance to the boundary layer. Ultimately, an area of low pressure is created in the channels and under the tail, functioning as low-drag, finless fins. Twin channels to create a more twin fin like performance relative to the single Coanda Channel tail. And no nasty fin gashes in my skin.
This Twin Coanda Channel planshape is a modified Retro Fish mid-section. [The first Retro (Lis) Fish was built in 1967. The first Boogie (SNAKE) Board was made in 1971 — looked nothing like its descendants.] All curves in my twin-channel prototype, except the deck rail radius, are derived from the same equation. The principal (channel-wall flare) equation is derived from a basic fluid mechanics curve. I find no use for flesh piercing points and foam that isn’t in the water for more than a few seconds…
Received my custom CNC shaped twin, Coanda Channel BB today.
The CNC shaping by a young man (Shawn 0.) in Idaho is exceptional (his side business). Best CNC prototype shaped for me to date. Made possible because of our Sways CAD guru’s (“jrandy”) ability to convert my equation data into cutting files.
I need a place and time to test this magic carpet. No doubt in my mind that it will rip…
This is the “first twin-channel prototype” I’ve built.
In that my technology was patentable, searches did not turn up anything similar.
If somebody wants to build one for personal use, go for it. And please post ride reports.
I’m landlocked and my testing opportunities are limited. Hope to get a chance sometime this year.
I also need to get somebody a lot younger than me to ride it for videos.
The twin-channel is easiest to use for my current (wide-tailed) applications (18”). Using them for a longer stand-up board would be more challenging. If moved up to the wider section of the board, it might be possible. The twin channels in my new build would need a minimum of 14” width and creative rail shaping.
A single channel could be added to a longer board as depicted in figures 16 & 17 at this link.
What may not be obvious is that there can be no tail rocker — must be flat from the end of nose rocker to tail end for channels to work properly. Bottom of the channel serves as indirect tail rocker.
I should have said tail rocker must be flat from the end of nose rocker to the end of the channel walls at the channel exit.
As shown in the figures (16 & 17) the channel bottom curve can extend beyond the channel walls to create a longer surfboard.
Let me know if you get thorough board dimensions. Maybe I can help determine good channel(s) location.
