MVG's... not a gimick, just hard science.

General Discussion
1

This is what I shared with Mark Spindler - the “creator” of the MVG.  I looked at the NASA patent, and decided that the increase in lift created by the vortices would, (Based on my study/participation of Swaylocks threads and what many folks agree - lift on fins creates speed.) increase speed, as my friend,  and test rider, a former world traveling pro, said he experienced.  Please be encouraged to comment.

After 27 sessions He added the MVG’s to his Channel Island 7’2” tri. Round pin tail.As a former traveling pro – once sponsored by CI – his surfing is very solid, to put it mildly.  He usually rides CI 6’2” for similar conditions to the day he first rode w/MVG’s – I told him it was 10’ @ 10”, but due to drop in swell, change of swell and wind direction, we surfed “A” frame peaks at a sand stone reef and sand bottom set up.  Head high sets, some doubling up, nice off shores.

** I have had ample opportunities to ride my 7'2" before adding the MVG Fin System to my board.**

** The board holds its speed more through the well/trough of the wave with the MVG system and I found that I could approach the top/lip of the wave more vertically when setting p my top turns with the MVG.**

** Overall I believe that the MVG system improves the maneuverability of my board in that adding speed loosens up my board when leading into a turn.**

** Final thought, I completed several figure 8 cutbacks on lefts w/the MVG on waves where I previously only would have had enough space to have completed an S-turn with a lateral bank off of the white-water.  By having more ability to cut a tighter arc, and subsequently hit the lip on the rebound, I was able to project back onto the face with more speed. **

** The added maneuverability allowed me to cover more wave face and to utilize more parts of the wave; therefore, I could maximize each wave's potential (a surfer must perform radical controlled maneuvers in the critical sections of the wave with speed, power, and flow to maximize scoring potential) further than I could have done w/out the benefits related to the MVG.**

** I'm a believer in this innovation.**

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I did a search to see some pics, but they seem to be gone. If anyone has pics, or a link to pics, could you please post them??.

They sound interesting, and after trying herb's sc's ( with positive results ), im interested in these.


CHeers

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What’s an “MVG”? Never heard of 'em.

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I’ll have to try and find some pictures… The ones that once existed here are gone.

Imagine two tiny fins - lookin’ like “your proto typical fin” but sort of squat - the first one is about 1/2" high followed immediately by a 5/8" one.  these are set about 7/8" in front of the center fin.

They set up two small tip induced voticies which wrap around the center fin and help keep the water “attached,” thus increasing lift and reducing stalling due to flow separation at high angles of attack.

What this does for the rider is what my buddy wrote about.  The most basic thing I noticed is  the board can turn sharper.

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I STILL HAVE A FEW IN MY COLLECTION.

MARK’S A HECK OF A SMART/NICE GUY.

HERB

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So, MVG = Miniature Vortex Generators?

Have they been used on single fins?

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yup!

herb

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pic courtesy swaylocks - dunno who posted it originally.

 

and  this pic

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Mahana…where are you and your superchargers?!

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Yo science fans,

 

The photo in the post above is of the second board I shaped myself;.It’s a 7’5"x 21 1/2" x 3.0" clark foam egg with a double 4 bottom, double 6 deck Resin Research epoxy shell on it The fin is my Mokarran template, which I use as a quad trailer and as a speed center fin. The MVG glue failed several years ago but I will say that this board and my 8’0 Freeline speed platter (where it now lives) surfed with as much facility and speed as they ever have with the little finlets ahead of the main fin. I haven’t bothered to make a set of MVGs myself as my struggle to return to normal after my hip replacement operation (one year ago today) continues to be a somewhat complicated process. In addition my prototypes and fin experiments have taken me in other directions. I’ll spare you all the details.of the hip saga: Suffice it to say that everytime I think I’m in the pink some new set back shows up. At present I can only stand for about 10 minutes without my femur going crazy. (Minor stress fracture around the titainium prosthetic rod – maybe?) Anyway it’s it’s elevation and ice, ice, ice. Beautiful surf here in Santa Cruz today, I’m bumbed.

 

The idea of a small fin ahead of a large one is a most functional arrangement. When I;ve been able to surf, and I have a few times. I’m almost always on a Twinzer. The MVG idea, the Twinzer canard set up and Herb’s “Superchargers” all belong to the same family. They serve a similar purpose to the finlets on a tuna or the little feathers on the leading edge of an owl’s wing: They let the main fin or wing work in a wake and thus the vortex generated by the small leading object is projected upon the large working area. As a result the large fin enters the water in a read formed vortex and In this way centripital energy is amplified. Wil Jobson didn’t use the word (centripital) the last time we talked but the energy spilling into the vortex is where all the power is. As I recall Wil said something to the effect that fin power and flow velocity is aided by some 20% oir so by have the “Twinzer” effect. The MVG system and superchargers are of a very similar nature.  Next time your out in a little power boat and you want to make a little extra speed drop in behind a bigger hull and run it’s wake. You fell the difference immediately.

I could go on and on but I’d much rather be able to stand for a while so I can cut and grind.

Mahalo, Riich

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The only thing I have to add at this point  - other than all well said - is the picture is of “super chargers,” as best as I can tell.  If you put those two in a row and put them in front of the center fin, then you would have a very very close approximation of what MVG’s look like. 

The ‘M’ stands for ‘Multi,’ as there are two of them, and thus they set up “multiple” vortices.

By the way - Blessings on your healing Rich,

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What would the effect be like if you only used one of them?  

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[img_assist|nid=1046618|title=Oneula's Chung|desc=|link=none|align=left|width=51|height=100]

 

 

This is Oneula’s mvg fitted board, and there’s the other pic kindly re posted by  WWMark - the MVG’s are the little red n yellow finlets , they look like they’re fixed in position too, unlike the others.

Apologies if that green board doesn’t come up full size , I don’t quite get this forum upload method yet.

Hope you get well soon , Rich.

 

 

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“Spot on” as some say - Re. the picture of the little red n yellow finlets.

 

I think one would have less of an effect.  The NASA patent show at least three in a row, as the tuna - from which all this sweet “bio-mimicry” came from.

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Some differences: A tuna’s finlets are behind the second dorsal and not in front of it like the MVGs are to a center fin. A tuna’s tail is moving back and forth. 

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Some differences: A tuna's finlets are behind the second dorsal and not in front of it like the MVGs are to a center fin. A tuna's tail is moving back and forth. 

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Well, the dirty little secret is that the finlets are to increase the efficiency of the tail fin.    Little known is the fact that the finlets can, and are, independently articulated in sync with the beat of the tail fin.

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How do you attach the mvg's to the board?, do they go on the board, or the fin somehow?. And do they work on a thruster setup? or is it just a single fin design?. Are they available, or makeable at home in the shed??

 

Tuna swim much faster ( into my stomach ) with some sweet chilli too BTW haha.

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Interesting, Bill. I learned that tuna were fast b/c their tails were the only thing beating. The more the rest of the body undulates, the more drag, and the slower the fish. Do the finlets move while the body stays stiff?  

 

Now I’m very interested to test these MVGs and/or a pair of Herb’s SC out. 

 

 

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My suspicion is that the body has very little movement, which is the reason the finlets themselves are able to articulate.

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I don’t want to sound like the Guru cos I’ve never used em or even seen them in the flesh - ( this thread has re kicked my interest though ) .

There’s truckloads of stuff in the archives  - guys just superglue them on the bottom I think they were moulded with resin n chopstrand.I think I read something last night about Rich making that pink fin with a spesial extension on the base.

As far as thrusters go Herb n co had a setup they dubbed the Crossfire ( I looked all through my files for a pic but nada) , SC’d side fins and MVG’d  centre.

That thread about moulding fin bases is the biz , make a prototype out of balsa or something, paint it etc. then do a silicon mould.

p.s. Anyone -  is that little white fin on the buue board a 'thresher '?