Been thinking about this for a while after seeing Herb’s superchargers and Chips single tabbers.
What would happen if you were to put one either side of a centre fin in this arrangement…
I value any opinions on this… (picture of blue fin used without Chips permission)
I’ve already worked out how to add this sort of system to a box or tab…
Just need a little direction in making it happen…
Move the two small fins another inch forward, for best results. More speed OUT of your turns, and greatly reduced tendency to stall during abrupt, high AOA, maneuvers. I think you will really like the results.
Man that thing is gonna be so fast…
you’ll be able to go whaling from it!
Bill, why? thx
Thanks Bill,
What about the foiling, flat inside, concave to aim the water force at the fin, toe in/out.
I’ve been thinking about this for a while but need input from the experts…
My vote is for symmetrical foil, all three fins…and for ride reports! I agree with Bill, you probably will be able to pull off higher AOAs without stalling, I’m just wondering if the little fin that first sees the flow could partially ‘blank’ the center fin near the base…thoughts on that, Bill?
JSS
My thought is that the front finlets would concentrate the flow onto the base of the centre fin giving it more hold in acute situations…
I’m going to build a prototype on the weekend and give it to Chip to find out what he thinks of it…
No toe, symmetrical foils. Don’t waste your time on a concave.
Make it one on center–make it flexy enough to bend side to side…works for me
LOL hell I dunno
“My thought is that the front finlets would concentrate the flow onto the base of the centre fin giving it more hold in acute situations…”
I think you are very correct… you are sacrificing the hold the little fins would give you to keep the larger fin working.
After looking at it more closely, I think you will be fine, no blanking problems unles you are at huge AOA.
Janklow is correct, though. The main effects of the finlets will be to keep flow attached to the base of the center fin. In order not to lose the tip earlier to stall, a flexy tip that ‘wags’ kinda like the SurfTrux would be helpful…
Or just Thrailkill’s double center fin setup, whereby both fins are mutually supportive…
JSS
Another option to try:
Happy Birthday Hisky.
Great idea, I’d like to find out more.
I’d be interested to find out how it would perform with the small bites placed behind the single fin.
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Maybe you could place 3 x 10.5 boxes about 1.5” apart and play with the position.
Bills also mentioned in the past about having 2x double foiled single fins positions next to each other. I think you first brought this up on a thread about the merits of double foiled keel fins and how they work.
I’d also like to learn more about the role of a trailing fin
Hicksy,
There’s one of the Swayers, apologies, I’ve forgotten the name…embarrassment because he had some contact with us about this type of fin arrangement, but I’ve lost loads of old mail on another computer.
Spiral vortex initiator…or some such name…and his theory was strong. A small tab just in front of the centre fin.
That man…Put your hand up again, please. And apologies, again…
Josh
Hi Josh -
Maybe you mean Mark Spindler and the multi vortex generator (MVG) ?
Herb Spitzer (superchargers), Taylor Olson and others have played around with the idea. There is a recent shot of Taylor in the tube on a board he made with MVGs in front of center fin.
Not a stupid idea.
John,
That’l be the one…
I clocked the theory as a solid one, though I’ve yet to try it, and I would’nt expound it to Hicksy without the right credit going to Mark. So now at least Hicksy can be assured he’s not fumbling in the dark.
Josh
That looks really interesting. I’ve been spending way too much time on airplanes, lately, and amusing myself by studying all the vortex generators stuck here and there on the wings and fuselage, and wondering if that could be applied to surfboards, and a lo! quick google search turns up:
We could have some fun with these little stick-on things:
Vortekz Universal Vortex Generators Black 10 Pack
Part#: VGBL-001
Vortekz Vortex Generators are universal to fit virtually all Cars, Trucks, Vans, SUV’s, RV’s etc…
Price: $19.99
VORTEKZ GENERATORS
Description
Vortex Generators are commonly used on aircrafts to prevent downstream flow separation and improves their overall performance by reducing drag. Vortekzâ„¢ Generators Delta Wings allow you to achieve similar results on any vehicle you own in only a few minutes.
Grant
looks like you’ve been milling this idea around since last year.
Herb had a lot of success mixing up his SCs(superchargers) on the sides with an MVG from Mark in front of the center:
Read about Herb’s Crossfire design here:
http://www.swaylocks.com/forum/gforum.cgi?post=138349;search_string=crossfire;guest=16893737#138349
And even Bert and Roy had alot to say about the design benefits of the MVGs here:
I bet just trying one of Mark’s MVGs would be a good starting point as most of us that have like Halcyon, Herb, Taylor and others have been impressed with ours.
Dave Skedelski from Surfco was the guy who turned me onto them years ago as Dave’s always fooling around with new stuff like this.
Maybe get some of these stick ons from this place Alan posted and try some different layouts in front of a single… You and Rubberlove haven’t posted any of your crazy rocketship salvage adventures here in awhile anyway…
things are getting way too serious…
Mark was kind enough to send me a couple of MVG’s and I have noticed a definite improvement in the way the board follows through on the top turns.
It’s a pity they are not in production at the rate I change boards, as with the adhesive they are hard to remove.
I think it is Wildy who is into the inline single fin set-ups. I haven’t seen him post for a while.
Thanks John.
It’s been over ten years since I eureka’d the MVG.
As a matter of public record; MVGs are a proven device. In the years since I had the idea there’s been a lot of theory and hard science including a NASA patent and costly NASA wind tunnel tests to back up the MVG. So let me say for the record that Hicksy’s idea is not far fetched at all. It’s twice the preferred NASA configuration, keeping in mind that a wing presents a particularly one sided flow pattern due to gravity so offsetting the VG in front of a wing is desireable. Precise location information is available. But keep in mind this is a device that has been patented by The US government and requires a special license to produce. (I get special treatment as I was the inventor.) Furthermore it has been scientifically determined by wind tunnel testing at Langley that there are noticeable differences in one two and three or more finlet configurations with two and three being the best performers. Size too matters.
Contrary to plane wings, surfboards present a totally unique set of criteria independent of any other form of vehicle or craft. Therefore I put my MVGs directly in front of the trailing fin.
Hicksey’s setup I suspect could possibly cause the fin to be flow starved, (or maybe not) so like Bill Thrailkill said try and move the whole set up forward. But first try it the way you have it. Then monkey around with it. The more test results you have the better. I’ve stuck with my first notion, since it was based on the inline finlets of the mackerel family, but others have played with location and found some remarkable benefits.
I’d be very interested to hear how it all goes.
I like your template…I agree with Bill,move your drafters up at least : half it’s base in front of the leading edge.
Another tip…Keeping the template the same and without losing the general dimentions…tip the whole template forward 5-10%.
This will lead the main fin thru the turn quicker/faster w/o any adverse reactions.
H