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Extreme Dolfinism
- Thread starterREVAN
- Start date
Thread Status: Hello
, There was no answer in this thread for more than 60 days.
It can take a long time to get an up-to-date response or contact with relevant users.
It can take a long time to get an up-to-date response or contact with relevant users.
For ultimate awesomeness:
-play above video and click MUTE
-play Electronaut in separate window
-hypnotize
But I understand Your song choice was based on strong lyrics that match Your story (chasing 20yo dream?) and it's great song too
[ame=http://www.youtube.com/watch?v=pjJk3bbE87c]VNV Nation - Electronaut - YouTube[/ame]
Yes, this is a 20m pool that was constructed for developing these monofins. Without testing, there can be no progress!
I never changed the factory default of the camera. I guess I should look into the other resolution options. I need to make a new camera stabilizer mount that I can travel with. This one is too big and does not fold. The new one should be configured to keep the camera mount outside the FOV for the settings used. What H2 settings do you recommend for this perspective?
FYI: I still have not heard anything from GoPro about a date for their flat lens UW housing. Time is getting short, as I need something to get clean UW video by about mid April to use in Hawaii.
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My favorite setting is 1080p, that's 1920x1080 30FPS. With HERO2 You also have two fields of view, 170 and 127 deg wide so You have to play with that and see which one You like better.
I am waiting myself for housing from GoPro, I'll wait two more weeks and if they don't deliver like they promised I'll be buying this one + Magic filter. Their lights would be better but I feel bad spending $800 on few LED's..
Backscatter Custom GoPro Underwater Housing Blur Fix Glass lens and Underwater Removable Filter Mount
oh man, what a fin !
Ron, when we where speaking about the X 18 in december i was feeling a slight apprehention about jumping onboard. but you have really hit the nail on the head with this fin. i don't think i'll be procrastinating too much in regards to the X 20.
already smelling the call of the open ocean...
Ron, when we where speaking about the X 18 in december i was feeling a slight apprehention about jumping onboard. but you have really hit the nail on the head with this fin. i don't think i'll be procrastinating too much in regards to the X 20.
already smelling the call of the open ocean...
Ron, as it is known, the thrust of dolphins is mostly created by the utilization of vortices. Do you think that with the DOL-Fin something similar can be achieved? Is there any experimental/numerical data on this?
When touching the surface the bubbles indicate that the foil produces a rather clean thrust.
If anyone can, use a compressed air bottle and use the Dolphin like they use monofins in a competition, I would love to see a video of that.
Ron as a comment on your swimming technique, keep your chin to your chest. Roll you body forward. It will look better and I hope your hydrofoil allows for that technique as well.
For now the foil seems to provide more support and smooth action then the previous versions, did it change, what has changed? <I suspect the 'hinge' materal is a bit more stiff, and or the range of angle has been reduced a bit, and or your swimming technique has improved>.
Now it really start to look like a rounded of product ready for bigger numbers
- Sounds like a nice slogan, LOL
Love, Courage and Water,
Kars
If anyone can, use a compressed air bottle and use the Dolphin like they use monofins in a competition, I would love to see a video of that.
Ron as a comment on your swimming technique, keep your chin to your chest. Roll you body forward. It will look better and I hope your hydrofoil allows for that technique as well.
For now the foil seems to provide more support and smooth action then the previous versions, did it change, what has changed? <I suspect the 'hinge' materal is a bit more stiff, and or the range of angle has been reduced a bit, and or your swimming technique has improved>.
Now it really start to look like a rounded of product ready for bigger numbers
- Sounds like a nice slogan, LOL
Love, Courage and Water,
Kars
Yes, that is how it works. But then all fluid thrusts are generated by the utilization of vortices. Excluding buoyancy, as it is technically a gravity effect generated force, fluid can only exert a force on a body within it through rotational flow distributions (i.e. - vortices).
More specific to your point of interest; there are many ways to use vorticity to generate thrust, and the DOL-Fin's shed vortex patterns are more similar to the vortex patterns generated by dolphins than the are the patterns generated by other types of swimming fins.
I hope that answers your question satisfactorily.
Ron
One mistake I made was not putting a tile strip along the bottom of the pool. The floor of the pool is monolithic and lacks visual ques for a heading reference. I need to lift my head to see forward or I tend to drift off course into the side-wall. Besides, most recreational swimming is done with the head raised so that the swimmer can look around at the scenery. So, in that regard, this is representative; although the camera rig made noticeable drag also. By the way, lifting your head from the tucked position to look forward is a 25% drag penalty. I've measured it.
The foil suspension has some new PE guides that are unique to the X-series, but the basic function of the system has not really changed. The new parts were adopted to reduce parts wear and noise and to add an extra dimension for adjustment to allow for better bio-metric matching to the user.
Previously made statement: "...the DOL-Fin's shed vortex patterns are more similar to the vortex patterns generated by dolphins than the are the patterns generated by other types of swimming fins."
You can see the dynamic vortex patterns on a diver swimming through bio-luminescence at night. It is a low cost flow visualization technique and it looks really cool. The only problem is you need special low-light underwater cameras to capture the video with any discernible quality. So, while I've seen it in person on many different kinds of fins, I don't have any flow-visualization data to share.
However, there is plenty of empirical data that supports the previously made statement. The Strouhal number of the DOL-Fin can be estimated from the online videos. It can vary depending equipment configuration and technique, but it generally falls within the sweet spot between 0.2 and 0.4 unless someone is doing something very unusual. With good technique and the right fin settings, the Strouhal number will fall very close to 0.3, which is where dolphins typically operate.
Evidence:
The fluid thrusting elements of the DOL-Fin system comprise a semi-rigid articulating foil that generate fluid forces through the same mechanisms as a dolphin's tail.
Matching Strouhal numbers demonstrate the DOL-Fins move through the water like a dolphin's tail, shedding vortices with very similar geometric distributions.
Conclusion: The vortex patterns will be more similar to those generated by dolphins than would be the patterns generated by fins that differ from the DOL-Fin by operating via different mechanisms of thrust generation and/or operating at different Strouhal numbers.
If you want to know more read these:
style.org > The Strouhal Number in Cruising Flight
http://smithaerospace.us/information_links/BioFoilPaper.pdf
You can see the dynamic vortex patterns on a diver swimming through bio-luminescence at night. It is a low cost flow visualization technique and it looks really cool. The only problem is you need special low-light underwater cameras to capture the video with any discernible quality. So, while I've seen it in person on many different kinds of fins, I don't have any flow-visualization data to share.
However, there is plenty of empirical data that supports the previously made statement. The Strouhal number of the DOL-Fin can be estimated from the online videos. It can vary depending equipment configuration and technique, but it generally falls within the sweet spot between 0.2 and 0.4 unless someone is doing something very unusual. With good technique and the right fin settings, the Strouhal number will fall very close to 0.3, which is where dolphins typically operate.
Evidence:
The fluid thrusting elements of the DOL-Fin system comprise a semi-rigid articulating foil that generate fluid forces through the same mechanisms as a dolphin's tail.
Matching Strouhal numbers demonstrate the DOL-Fins move through the water like a dolphin's tail, shedding vortices with very similar geometric distributions.
Conclusion: The vortex patterns will be more similar to those generated by dolphins than would be the patterns generated by fins that differ from the DOL-Fin by operating via different mechanisms of thrust generation and/or operating at different Strouhal numbers.
If you want to know more read these:
style.org > The Strouhal Number in Cruising Flight
http://smithaerospace.us/information_links/BioFoilPaper.pdf
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