h a l f b a k e r y
Go ahead. Stick a fork in it.

meta:

account: browse anonymously, or get an account and write.

 user: pass:
register,

 (+3, -1) [vote for, against]

When I was building the prototype of Miniautilus, (an internally ballasted Archimedean-Screw propelled submersible) I had a year and a half to daydream about piloting the thing and work out the bugs.
I estimate that I took it about 25 years or so into the future with my musings and figured out how to store energy by imparting inertia to an inner flywheel, recoup that stored energy by engaging the flywheel and forcing it towards the back of the craft using the taper of the inner hull as a transmission, and steer it using gyroscopic precession of that same flywheel within a double-gimbal.
Patent pending the overturn of First To File theft of our First To Invent right. (but that's another story)

I also figured out how to make the water itself pull me through it as I pull myself through an artificial current... and then I figured out how to turn that current into a sort of rail-gun so that the best analogy I can think of would be; riding a ten-speed bike along the back of an infinitely long flat-bed truck travelling down a highway which is also moving in the same direction of travel, so that even though the pilot is only exerting enough energy to travel at bicycle speeds the overall velocity would approach aircraft speeds.
Underwater.
Without cavitation.
...and I feel like sharing, and the world needs it.

[neutrinos shadow] if you thought Coanda Tornado was hard to model then I triple-dog-dare you to try modelling this one.

The rules for the pedal powered submarine competition we were trying to enter insist on flooded submarines to move divers around quickly between sites without having to doff gear and provisions need to be made for expending exhaled gasses to maintain neutral buoyancy.
We could just let it out through perforations in the hull but it got me to thinking...
If a membrane were placed forward of the pilot and the exhaled gasses shunted there then three things would happen.
One; the spinning of the craft would cause the gasses to tornado.
Two; adding air to the nose-cone would cause buoyancy at the front of the craft.
The craft itself is a gyroscope though so any force exerted upwards would translate to either port or starboard depending on direction of spin.
Three; The inner flywheel could compensate for this precession to stay travelling in a straight line.

I realized that if I retracted the tip of the nose-cone then the tornado of air entering it from inside would displace the water within creating a pressure ridge at the tip which might very well be more aquadynamic than a point much like the dimples on a golf ball, I don't know.
What I do know is that if, when the nose-cone entirely fills with air, I impact the membrane containing the tornado then I will launch a tornado-vortex ring and that the distance that vortex ring travels will be determined by the power of the membrane impact.

Since the pedal powered submarine races have a 100 meter warm up area prior to the starting line, and storing of power is not prohibited, I could potentially launch a series of vortex rings in front of the craft and if I could lock them into position along the course length then they would induce an artificial current in the water which would look similar to a magnetic field if you released a bunch of neutrally buoyant objects into the artificial stream.

Turns out that sound has been able to be focused into a tight enough beam that if three men were standing shoulder to shoulder, only the fellow in the middle would be able hear what was being broadcast... and only in one of his ears.

Given the difference in speeds which sound travels through water compared to air, a focused sound beam could not only lock the tonado-vortex rings into position, it could actually impart extra energy to them in the form of spin as the sound waves would only contact the inner surface of each ring, slowing as they transition from water to air making each ring spin faster than when launched.

Okay, so right there, we could use wave-powered buoys to create focused sound waves and keep submerged intercontinental oceanic currents stable through a tunnel of vortex rings...

...but then I figured out how to pull the highway under the truck.

If you launch a vortex ring at another vortex ring travelling in an opposing direction the effect is an explosion of smaller vortex rings at right angles to the impact.
If you launch a vortex ring in the same direction as a slower vortex ring then the two rings leap-frog. The vortex ring overtaking the slower ring steals energy and is catapulted faster than originally launched.

If the craft travelling through this artificial current is capable of launching its own vortex rings then it would be possible to use either blue or green light heat lasers to excite the molecules of air within the systems of both rings causing them to expand and allow the craft to pass between them timed to coincide with their leap-frog.
If the heat were withdrawn at exactly the right time then the leap-frogging ring system would rapidly collapse just aft of the centre point of the craft and the resultant ejection would propel the craft at ever increasing speeds within the existing current much like an apple seed spitting out between two fingers over and over and over again.

 — 2 fries shy of a happy meal, Nov 21 2021

Microbubble Drag Reduction https://www.science...i/S2092678216306409
[AusCan531, Nov 22 2021]

[2 fries shy of a happy meal, Nov 23 2021]

Dyson fan current inducing experiment. https://www.youtube...watch?v=IGIDmlfdigQ
[2 fries shy of a happy meal, Nov 23 2021]

The power of vortex rings https://www.youtube...watch?v=JXkWSgU-CL0
[2 fries shy of a happy meal, Nov 23 2021]

If you're not logged in, you can see what this page looks like, but you will not be able to add anything.
Short name, e.g., Bob's Coffee
Destination URL. E.g., https://www.coffee.com/
Description (displayed with the short name and URL.)

Interesting, I'll need a lot more time to think through this one. [=]
 — pertinax, Nov 21 2021

Interesting, I'll need a lot more time to think through this one. [+]
 — Voice, Nov 22 2021

The goldfish rolls...
 — RayfordSteele, Nov 22 2021

Gyroscopes & focused soundwaves & vortex rings...
Talk about throwing all my favourite things into the ocean!
Wish I had a billionaire relative who was about to die & bequeath me a fortune... experiments must be done! (& they cost money...).
I was wondering if a focused-sound speaker (generally ultra-sonic) could provide propulsion under water on it's own? Water is (mostly) incompressible, so the "peaks" of the sound wave would (might?) push, whereas the "troughs" CAN "un"-compress (akin to cavitation) so shouldn't "pull" so much. There are instructions online for building ultrasonic directional speakers, but I'm not electrical/computer geek enough to build one :-(

 //Gyroscopes & focused soundwaves & vortex rings... Talk about throwing all my favourite things into the ocean! Wish I had a billionaire relative who was about to die & bequeath me a fortune... experiments must be done! (& they cost money...).//

 I know. That's why I turned my thoughts towards creating wealth rather than perpetually searching for a benefactor by giving away my intellectual property and haven't had a new brain-fart since I took on 'becoming' this new property by feel without blueprints. My head is full right now.

 I've decided that I will fund my own research. No strings will be placed on this particular autonomous puppet.

 I give away what I want to see made.Please take it. It is needed.

 Yeah I know how pompous that sounds, meh, whatever, time is short.

Aren't biannual Sunday days off the greatest?!
 — 2 fries shy of a happy meal, Nov 22 2021

Cool idea but I admit I'm struggling to visualise it. The expansion/contraction of the vortex rings is especially novel. Here's a [link] on some work done by the Japanese on microbubble drag reduction which, while widely know to exist, could help if you could 'shatter' the vortex rings just ahead of transit.
 — AusCan531, Nov 22 2021

 So there are a few ideas mixed together here and I can't figure out what problem you are trying the solve.

 Overall, I think you're being optimistic about the power of vortex rings. They're neat, but they're not magic.

 I don't think you can contain "intercontinental oceanic currents" with vortex rings.

You might be able to use vortex rings (with the help of focused lasers/sound) to propel the submarine forward. But it is probably more complicated and less efficient than a propeller.
 — xaviergisz, Nov 22 2021

 //Cool idea but I admit I'm struggling to visualise it. The expansion/contraction of the vortex rings is especially novel. Here's a [link] on some work done by the Japanese on microbubble drag reduction which, while widely know to exist, could help if you could 'shatter' the vortex rings just ahead of transit.//

 I will find links to help you visualize. No shattering, just a violent contraction of a stable system timed to coincide with the passage of the craft.

 //So there are a few ideas mixed together here and I can't figure out what problem you are trying the solve.//

 The goal is to figure out how to propel a pedal powered submersible at speeds not yet attianed.

 //Overall, I think you're being optimistic about the power of vortex rings. They're neat, but they're not magic.//

 Not magic.Just an underutilized phenomenon.

 //I don't think you can contain "intercontinental oceanic currents" with vortex rings.//

 There was a recent video where someone rigged Dyson fans through a coliseum which created an air current dragging balloons through it without any other power source.This is like that.

 //You might be able to use vortex rings (with the help of focused lasers/sound) to propel the submarine forward. But it is probably more complicated and less efficient than a propeller.//

 ...but it has no propeller. The craft itself is an impeller and does not use a fan to push a box. It pulls itself. No push.

 //Upon first reading the idea title, I immediately thought of the military applications (link). I think I also read somewhere that after the sinking of the Titanic, there was talk about building some ginormous jetties to redirect ocean currents to speed the melting of icebergs and make shipping safer.//

 The afflicted are amused.

 There are also super-cavitation torpedoes which create an air bubble in front of themselves and literally fly through the water.

This idea also isn't that. It is its own thing. My thing.
 — 2 fries shy of a happy meal, Nov 23 2021

 I have questions.

 // recoup that stored energy by engaging the flywheel and forcing it towards the back of the craft //

 Is "it" the energy?

 //if I retracted the tip of the nose-cone then the tornado of air entering it from inside would displace the water within//

 I'm picturing a double hull. I'm also picturing a "flooded submarine". That implies two spaces, namely, an inner space and an inter- hull space, and, (because "flooded"), neither is watertight. So at first, when you lower this thing into the water, they both flood.

 But then you mention a membrane forward of the pilot, with exhaled gases being pushed through it.

 Does this mean the pilot is exhaling into a tube, and the outlet from the tube is at that membrane? Obviously, the membrane is gas- permeable, but is it also water- permeable? I'm guessing not, but I'd just like to be clear.

 Is the "nose cone" the entire area forward of this membrane?

 Is the nose cone between the inner and outer hulls? If so, then is it separated from the rest of the inter- hull space?

 Is the "air" in the nose cone just exhaled gases, or is there ordinary air in there too?

 When you retract the tip of the nose cone, does that mean you're opening the outer hull to the surrounding water? Or does the nose cone enclose a separate space, outside the outer hull? And (related question) does the membrane give directly on to the space inside the nose cone, or is there a separate reservoir of exhaled gas in between the two?

{breaks for lunch}
 — pertinax, Nov 23 2021

//If the craft travelling through this artificial current is capable of launching its own vortex rings...// - surely this would consume energy and momentum though, so you wouldn't see a net benefit from them?
 — hippo, Nov 23 2021

 //// recoup that stored energy by engaging the flywheel and forcing it towards the back of the craft ////

 //Is "it" the energy?//

 No. Because I myself am the ballast within the screw I realized that pedalling too hard would cause me to invert instead of spinning the hull, but the contest is a straight line drag race and I want to be able to pedal as fast as possible so I devised a rubber coated flywheel on a swing arm to prevent this.Storing of energy is not prohibited but I needed a way to get that energy back when I reached the starting line.The top speed ever reached so far is 7.9 knots. I wanted to at least triple that. There is a 100 meter warm up area before the starting line and I wanted to store as much energy as possible before reaching it so that re-engaging the flywheel with the hull and forcing it towards the rear of the craft would cause the hull to rotate much more quickly than by pedalling alone. Like a figure skater pulling her arms in to spin faster.

 ////if I retracted the tip of the nose-cone then the tornado of air entering it from inside would displace the water within////

 //I'm picturing a double hull. I'm also picturing a "flooded submarine". That implies two spaces, namely, an inner space and an inter- hull space, and, (because "flooded"), neither is watertight. So at first, when you lower this thing into the water, they both flood.

 But then you mention a membrane forward of the pilot, with exhaled gases being pushed through it.

 Does this mean the pilot is exhaling into a tube, and the outlet from the tube is at that membrane? Obviously, the membrane is gas- permeable, but is it also water- permeable? I'm guessing not, but I'd just like to be clear.//

 No double hull. The Naval Research Facility hosting the competition wants divers to be able to get into and out of submarines without taking off their gear. Yes the pilot would exhale through a tube which carries the air to to the other side of the membrane.Personally I would like to build a non-flooded submarine so that the amount of air you bring down determines the amount of time you can stay submerged and nitrogen narcosis would never be a factor but the rules state flooded submarines so that's what I had to work with.

 //Is the "nose cone" the entire area forward of this membrane?//

 Yes.

 //Is the nose cone between the inner and outer hulls? If so, then is it separated from the rest of the inter- hull space?

 Is the "air" in the nose cone just exhaled gases, or is there ordinary air in there too?

 When you retract the tip of the nose cone, does that mean you're opening the outer hull to the surrounding water? Or does the nose cone enclose a separate space, outside the outer hull? And (related question) does the membrane give directly on to the space inside the nose cone, or is there a separate reservoir of exhaled gas in between the two?//

 The space in front of the membrane is separate from the rest of the craft and is filled with water until exhaled gas displaces it.

 // generating its own vortex ring would consume energy and momentum.

 Correct. At best, this might be an efficient use of energy, but it's not free//

 Not free no, but since the energy in question is already there from the spinning of the hull and the exhaled gasses then the energy spent to create a vortex ring is merely smacking the membrane really hard and would have been completely wasted otherwise.If I am right about a series of vortex rings creating a current then that energy has not been spent... just stored for later use.If I am right about sound waves imparting more energy to the rings than it originally took to make them and if I'm also right about surfing the leading edge of a vortex ring leapfrog adding to that current then my goal of tripling the world speed record is attainable.

Even without the leapfrogging vortex rings I think I could at least double the record speed with just the internally ballasted Archemedes screw hull alone.
 — 2 fries shy of a happy meal, Nov 23 2021

 I know.It took me a year and a half just to build a working prototype of the internally ballasted screw with a flywheel torque precession steering mechanism portion to zip around in the water, but it works exactly the way I saw it working in my head.When my subconscious figures something is important enough to overlay my actual sight with images of what it sees it's usually for a good reason.

I'm rolling with it.
 — 2 fries shy of a happy meal, Nov 23 2021

^ seconded. Full-baking, even at scale, & especially of completely-nuts-but-awesome stuff, needs to be shared, at least for constructive criticism...
Even if you're not ready to release video into the wild of YouTube, an e-mailed copy (or even just a photo of your model) to interested parties (ie. me, [a1], etc) would be awesome.
I solemnly swear that I will not copy, forward, up-load or anything related.

 I will link here to the stuff I've already posted. I can't link to any vortex ring experiments because they've only been in my head before I posted this.

 Welp... [a1] beat me to it.

 // Made any material progress since 2016?//

My wife and I sold our home in 2017 and everything we owned got stuffed into sea-cans for three years while we searched all of BC for where we were going to settle. We're still not fully unpacked.
I've got about three and a half years left on my self imposed 25 year hard labour sentence before I get to play again. Hopefully no time gets added on for bad behaviour.
 — 2 fries shy of a happy meal, Nov 24 2021

I think your sentence needs to be reduced for GOOD behaviour. What little I've seen of your works is mighty impressive.

 Thank you for all that explaining. Now,

 //filled with water until exhaled gas displaces it.//

 So you've got a cone, and it's got a gas- permeable membrane in it's flat back face, and it's initially full of water, and it's oriented horizontally, so the apex is not at the top but halfway up the height of the cone, pointing forwards. Then ... you open a hole at the pointy end and push in gas through the membrane until the water is expelled?

 At this point, what I picture is the gas collecting in the upper half of the cone, but the lower half staying stubbornly full of water while excess gas bubbles out through the hole at the pointy end.

To prevent this, you have a tornado; does this mean that the air enters through the membrane at an angle, and at much higher pressure than just breathing would provide?
 — pertinax, Nov 24 2021

 The membrane is not gas permeable it is like a drum skin stretched across the section of the nose cone in front of the pilot.Exhaled gas enters this front chamber through a tube which contains a one way valve.It won't matter what angle the gas enters the chamber the spin will cause it to tornado, and no extra pressure should be needed than simply exhaling.The gas will attempt to fill the upper portion and leak out, as you said, but the spin of the craft will drag it into a tornado and keep it hugging the walls until water at the centre is displaced.

 If the membrane is then stretched back and released or impacted from the pilots' side then a vortex ring will be created.

 Vortex rings already resist buoyancy until their energy dissipates so focused sound may not even be needed to create a current within a chamber. Launch distance of each ring is determined by membrane impact strength so as long as the energy of each membrane impact is slightly less violent than the previous impacts the tornadoing vortex rings should create a tunnel and induce a current pulling any neutrally buoyant object through if that object is small enough to fit.

Focused sound waves will just make them spin faster.
 — 2 fries shy of a happy meal, Nov 24 2021

 //the spin of the craft will drag it into a tornado and keep it hugging the walls until water at the centre is displaced//

But, but ... won't the spin of the craft act like a centrifuge, and make the water hug the walls, not the gas, because the water is denser?
 — pertinax, Nov 25 2021

 Perhaps...

 I see the trapped air constantly trying to rise and since the centrifuge is horizontally oriented a portion of that air gets dragged downwards which would start a thin air tornado near the top of the nose cone. Once enough air has entered the cone for portion of it to be dragged all of the way around before it can rise, it should then centre the water rather than the air. If the centrifuge were vertically oriented then for sure the air tornado would be trapped in the centre.

 I will need to experiment with that but it is secondary to being able to create an artificial current in the first place.Creating a leapfrogging vortex rail-gun from that current is a bit of a stretch and I won't know until I try it out.

I never know if the things which pop into my head are workable or delusion until I build them, but I intend to find out.
 — 2 fries shy of a happy meal, Nov 25 2021

If the air & the water (& casing) are both spinning, the water (denser) will be at the outside. If the air is spinning around the outside, at some point it will be "under" the water (assuming enough volume of air), then gravity will take over & put the water back at the outside/bottom.
Also, your small-scale test video only shows a left turn. I assume it turns right with no problem as well?

^Four lefts make a right.
 — AusCan531, Nov 26 2021

 //at some point it will be "under" the water (assuming enough volume of air), then gravity will take over & put the water back at the outside/bottom.//

 I get that. The thing is both air and water will want to tornado so they could very well split leaving a sort of funnel shaped yin/yang cross section of two separate tornadoes... that's just not what I see happening.The path of least resistance, once enough air has been trapped and spun enough to wrap 'under' the water, will be for the air to rapidly climb the upward rising curve of the cone creating suction allowing even more air to slip beneath until it connects with its upper self. There will be much turbulence just before air forces its way beneath water. Afterwards the weight of the water will just compress the airflow to a thin boundary layer as more and more of it is forced from the tip of the nose cone.

 //Also, your small-scale test video only shows a left turn. I assume it turns right with no problem as well?//

 That test was only one of several. There was no steering mechanism working at that point so the left-hand curve was due to uneven friction as it was not fully submerged.Testing the steering mechanism required building a neutral buoyancy simulator, (which wasn't ideal), but it let me get the other proofs of concept on film. I've recently found our flash drives and some of the photos are on them but none of the videos. They are in a laptop that wasn't supposed to get packed by the movers while I was at work in a box somewhere I haven't stumbled on yet.

 I can describe it though.

 I used a mortar, (stone bowl) as the flywheel with an electric motor inside it to spin it up to speed. It acted as both steering mechanism and ballast at that point.The mortar spun within a gimbal. That gimbal was also within another gimbal so that two servos could force the flywheel to tip in any direction desired. The effect forces a neutrally buoyant craft to turn without rudders.

 For the simulator I made a cradle of chair casters for the hull.That cradle was held in a wooden halo with four more chair casters radiating outwards from it.The halo sat within an extremely large metal salad bowl.That salad bowl rested on steel ball bearings riding the outer rim of a large drip tray of a planter.

 It allowed the craft to turn laterally, tip upwards and downwards and spin simultaneously.

 That's as far as my experiments got to before we moved.

...and now you know why I am no longer allowed to raid my wife's kitchen when I'm in mad scientist mode.
 — 2 fries shy of a happy meal, Nov 26 2021

All good. I was just hoping the "left turn only" wasn't a precession effect from a naughty gyro. Full gimbal = sweet!