Boeing Wind Tunnel

[Steve in Seattle]

Winglets- I first started playing with winglets in the 80ÃÔ then patented them on my Flying Force in 1995, but before that I had numerous companies seek out the proto types to test out in various transportation industries.

The group from San Diego involved with the Stars and Stripes (America 3) racing in the world cup used the winglet designs from Force Fins to perfect their high tech keel to obtain maximum speed without drag. They actually took the fin and studied its characteristics in the Boeing wind tunnel. Winglets are proven and that is why I decided to put them on the Flying Force Fin. Just a bit of history and more to come about winglets, VBC-variable blade control.

Ummm... you're not suggesting that you invented winglets are you?

I mean really, they were used on LeMans and F1 racers since the 70's, and on small aircraft even before then. Preventing spill-over is one of the oldest tricks in aerodynamics... wing ends are/were the most classic solution.

Just looking for some clarification here... I smell a whopper.

 

[uncleavi]

He is talking about the use of winglets on Fins.

 

[Susanne]

The design process evolves in various ways. Bob did not look at fins on a 1950 automobile, my parents had one of these with fins, which also serve as winglets, to get to the point where he was able to obtain a patent for winglets on fins. His process was to watch what the water was doing when kicking various fins, and forming shapes and mechanism to control that water -- one that is adjustable, and all of which were unique and patentable. Engineers working on the revolutionary keel did place Bob's Force Fin into Boeing's wind tunnel. Our understanding from them is that analysis of the flow of water across Force Fin's wing tip was integral to their ultimate design decisions. Just another perspective as to how well Bob makes his fin design choices, which goes into making every Force Fin design optimized for its user.

 

[Steve in Seattle]

He is talking about the use of winglets on Fins.

Yeah, I suspect thats the case. I just felt it prudent to complete the story here.

The prose about winglets being tested in a wind tunnel is also a little misleading IMO. Ask any engine builder to compare flow patterns of a cylinder head on a dry (traditional) flow bench vs one using a liquid intake charge (modern/advanced designs) and you'll bring up a whole textbook discussion on the differences between low-density and high-density flow patterns near mach 0.6 (where intake charge is most efficient and starts to degrade beyond that). Shifting the conversation to a completely submerged liquid at say 20 knots for a keel, or 2 knots for fins makes any meaningful data from a wind tunnel suspect.

I suspect the kneel in question found the force fins simply a cheap and reliable source of such a winglet model they could verifiy in concept using a windtunnel on their spare time... Sort of like using different toy airplanes as to validate building of larger (more expensive) models for proof-of-concept testing before writing the big check.

I agree that the idea works (airplanes find its more beneficial at lower speeds than at high velocities for example), but I hesitate to see a strong alalogous data set between a 30knot race yacht and a 2knot fin.

Great idea, plenty have used it in the past, I'm just suprised someone would quote a boat or airplane dataset to validate such a low-speed, and probably more importantly, such a variable angle application. Doesn't mean it wrong... but it doesn't really mean its right either.

</Devil's Advocate>

 

[Bob Evans]

Steve, are you a diver? and is your occupation really a pimp? I am not into the Devil stuff since the world's full of it lately but I have asked the expert to help you better understand the Boeing story and hopefully he will feel like responding to your comments. Best Bob

 

[barney@frogdiver.com]

I was a design engineer for the America Cubed team in 1990to1992. I worked on the tab and rudder designs. I selected the force fin profile to test the winglets on the "geek" as we called it.
We tested the stainless steel model of 1/2 of a force fin. We had the use of the Boeing wind tunnel. We used a larger version of the test part on "America 3" and we won. Being a long term friend of Bob, I disclosed our test data to him for use in making a better swim fin. As a contractor to A3 I retained all rights to any technology that I provided. I gave Bob permission to use the design in 1993. I have use force fins with the winglets since Bob provided me two sets #1 and #2. As I said; A3 used the design and we won the cup.

 

[Bob Evans]

Barney, just finished the final production mold for the ML size Flying Force. 10am PST. Started last 2-19-08 and will have a good drink tonight...So we now have Medium Large, Large, Extra Large, Extra Extra Large and finally the largest foot pocket in this World, Extra Extra Extra Large. Thanks for setting the record. I sent you Bob Kirby's new book " Aviation Visionary .."Smilin' Jack" Conroy. Love

 

[edwinh]

Finally, I doved my TD Flying Forcefin (TDFFF) after a long drought (monsoon season). After 10 warm-water dives (5AI, 5DM), this is my feel of them compared with my TDFF.

They are as responsive as the original TDFF and are a little easier to fin. They have a more powerful frog-kick. The control is superb. It accelerates well for me to reach my students in need quickly, stops me quickly.

Finning backwards is easy. Fine control adjustments are easily achieve with minor ankle movements.

I did not go for an underwater sprint, so I can't comment on the top-speed (not that this is important for leisure diving). Good in currents.

They work effectively on the surface swims with a modified side scissors finning, keeping the fins from breaking the surface.

After years of usage, my almost-opaque triggerfish-battle-scarred greenish-blue TDFFs are still in good condition. They'll probably last me till I retire if not for the itch after seeing the beautiful TDFFF and trying out a friend's normal FFF.

The TDFFF's foot pocket is definitely more comfortable than the TDFF. In all, I really like the Flying Force! Thank you, Bob, Blair, for getting this beautiful pair of fins to me quickly. Cheers!

 

[Bob Evans]

Edwinh, Looks like your flying. The next pair just flew off to Russia. Best Bob

 

[uncleavi]

I made sure my purple with sparkles Flying Force Fins went with me to Florida