Some ideas

[yipster]

...

trouty?

since if it isnt gonna be a cat i am with you that it must be a dog!


:) yipster

still reading your einstein and have heard of ships using towline electric power... interesting!

checked fijnman (stanford prof on magnetism) cant find flaws and your going beyond that, eh... got more...? how much power/weight are we talking about about? on a cat, a swath...?
got more:?: :?: :?:

[duluthboats]

yipster, and trouty, the two together. :eek:

I think trouty is out fishing. We might not see him for some time.

Gary

[yipster]

:D

[Willallison]

:eek:
Trailerable?
Home-build for under 100K ?
Sorry Yipster, doesn't really fit into the O-1 ethos. As a proposal for Trouty's fishing machine however.......;)

[yipster]

Garry,
Thank you for saying!


Will,
Thank you for the reaction, at least I contributed (to late) some well intended thought to O-1 as I –for one- now believe these requirements would be best met with cats or even better: boats on legs. I believe that for many reasons, but it does not simplify design.

Sorry its so rough sketched Will but these –nasty- legs fold in and are sized for a trailer.
Can understand do it makes you "eek":eek:

So far the serious part, the funny thing is in doodling around while thinking of trouty’s expression on cats and dogs. The story on free energy, thee, booz and the wc. And than I drew a dog. Don’t you see a dog that lifts its leg in the sketch? It was a coincidence but thought it was funny, sort of appropriate and hope you see it to?

But ok, I’ll keep this one for myself (not in dog form!) as we all like our “own” ideas and boats best I guess. When I got this one worked out a bit (if possible) I’ll show again ok?

On free energy however there is an open worldwide discussion going on and from what I understand so far its not even to expensive or difficult to make.. ok, ok, I still havent seen it, but wouldn’t thAt be a wish to the ghost that came out of the bottle that beached…. (I don’t drink either)


Morning / Goodnight
Yipster

[Willallison]

But ok, I’ll keep this one for myself (not in dog form!) as we all like our “own” ideas and boats best I guess. When I got this one worked out a bit (if possible) I’ll show again ok?


Far be it from me to throw cold water on your obviously enthusiastic creativeness - I look forward to watching the idead develop.......

[Mike D]

yipster

When I saw your sketch I thought it reminded me of something I read about many years ago but I had no idea where to find it. Completely by accident I saw it in this site where I was looking for powering boats. It is the first item in the list

http://www.rexresearch.com/boats/1boat.htm

Some other interesting methods don’t you think? Many other articles on unconventional systems and ideas elsewhere in the site.

Michael

[yipster]

...

yes Michael, i do think thats very interesting!

forexample:
Using the power of the waves to drive a stationary power plant has been proposed before, but it remained for a Long Beach CA inventor to design a wave-operated mechanism to propel a boat. Models used to try out the odd principle are reported to have shown surprising speed in tests, one miniature 18-inch craft attaining a pace of 5 miles an hour.talking about free energy...!

great site that gives much more inspiration out of the mainstream just as they mention, thank you!

:) yipster

and incorporating wave energy into a swath seems a sinch, well sort off - getting that speed however... :confused:

[Jeff]

Thanks for the great link Michael - interesting site!

[yipster]

Hello all,
Yes it was this rookie that suggested a O-2 category for those of us that are thinking of something out of the box, now I blush seeing O-2 :) :( :o :D ;) :p :cool: :rolleyes: :mad: :eek: :confused: :!: :idea: :?:
Aim is giving another answer to the same design envelope as we all are in the end boat nuts. Lets hope trouty makes a breakthrough in scalar energy, he also mentioned simply putting the prop up front taking the wave away. Has anyone ever seen such a design, has thoughts about it? Or rigs like in MikeD’s http://www.rexresearch.com/boats/1boat.htm that elsewhere also mentions de Palma’s study on free energy and much more.

How about wave energy for propulsion? Sounds great to me. Just hope there is enough dare and fantasy -time to- here among us to discuss, calculate, maybe later build such a experiment when the theory gets sound.

Who doesn’t like a more stabile, faster and low or free energy (or you name it) boat? Set up a poll? Or maybe it would have been better I’ve started a new tread in O-1? Now O-2 looks strange to me and I’ll tell you in advance I cant put my money where my mouth is! And thanks for getting the bug out of “my” control panel Jeff so I can delete and upload my “own” bugs again.

yipster
(blush)

[Willallison]

Option 2 huh...? Shouldn't we finish O-1 1st?

That aside, your SWATH is an interesting concept Yipster. Without any expertise in the field I'm not terribly qualified to comment - but hell that's never stopped me before !:D

With the size constraints you have placed on the boat (ie the same as those for O-1) you are faced with a boat who's crew (and their gear) make up a fairly big proportion of the total displacement. Subsequently any variations in crew numbers etc will have a significant effect on that displacement.

The very thing that makes a SWATH comfortable in rough water - the almost constant displacement regardless of immersion depth - means that it is greatly affected by large percentage changes in weight.

Unless you can come up with a way for ensuring that the crew will always sit in the same place and will always bring a given amount of gear aboard (such as could be the case if this were a commercial boat, such as search and rescue...), then I'd suggest that the concept would only begin to make sense for much larger vessels.

Also, if we are to consider an O-2 then I suspect there are those on the boards who would like to see us tackle something completely different to O-1 - perhaps a displacement boat - or, dare I say it - maybe even a snailboat....:eek: :eek:

[yipster]

You got some points there. A swath sure is interesting and like with many things it’s a matter of trade offs I think.

Take wave energy: high speeds can be obtained I believe but than systems I can think of now put the force on the weakest points. However a tri? But having such a device for free energy onboard beats a generator it seems to me.

Same goes for a swath, just trying to find something on the pro side. A smaller swath is only taking the chop and banging out, in giant swells it’s a different story, but imagine yourself anchored without too much dancing, that’s nice!

Balance can be manipulated by having less SWA, in design and operation and submerged trim tabs can be added for speed and cornering. How much gear and people you carry around usually? Than have a displacement (with its own "trade-offs") still weight distribution must be made in any boat. Specialy in a swath center of gravity also, as said it doesnt simplify design. But did you check the difference the swath concept makes in reduced wave drag? That means speed and economy!

As for O-2 ya think its better to set up a poll? With pleasure I’ve since some time been reading O-1, just thought (since these ideas are completely different) not to break that up…

yipster

[yipster]

http://www.schoellmarine.com/images/index/1b.jpg
harry schoell and his groundeffect "boat" showing it doesnt has to be thaaaat big...
i like it:Dyipster

[yipster]

http://www.heymanyachtdesign.com/KEEL2.jpg
from http://www.heymanyachtdesign.com/in3a.html
i'm thinking the lead out and some sort of a drivetrain in. like this rotary RPI (wankel), also in diesel. or hydroxin steam hybrid from mazda? than again: all particles are waves and...
(still thinking swath):cool:yipster

another possible O-2 project testdive today in the SF bay at: http://www.sfgate.com/cgi-bin/article.cgi?f=/chronicle/archive/2003/01/24/BA111378.DTL&type=news

[yipster]

struthkeelswathenginehull,

[yipster]

It isn’t easy trying to make the best of a “small” swath, I guess this boat has to be at least 3 to 4 ton and have its legs as far apart as possible. Stability and moving people (say 150 kg=150 liter) can be compensated by the progressively giving more buoyancy keel (400liter?) on the 1.2 cubic meter (1200liter hull)(s) giving 1200kg uplift.

Infolding legs on the “house” (max 4m wide for special transport) spread to a max 10m beam. Waterpumps and tanks operate the retractable legs. Also intended for manoeuvring and berthing. Having the engine(s) down the struts in the submerged hull(s) doesn’t make it easy in design and accessibility. Has nobody ever attempted to place some sort of a engine into a bulbkeel before in wonder? It’s always possible to go back to a cat. With legs? Middle hull carrying the engine? I just like this design better…

The calculator graphs for wsa hullspeed times 3 I assume, plus wavedrag on the 3 keels show, as I see it, a swath running comfortably on minimal swa can do economic speeds up to 40kt !? (I’m more than satisfied with 20kt) Formdrag may be giving the highest resistance than? Is hydrodynamic drag 10 times higher a aerodynamic? This wing hull form will come up with speed I hope to create a minimal swa on the keels. Work out the leg designs? How to figer out what forces (http://www.glosten.com/projects_research.htm) are involved, see also http://boatdesign.net/forums/showthread.php?s=&threadid=1178&highlight=swath Anybody in mechanical engineering with some advice? I started making a polyester model (3 legs) of a meter, have weights, and want to do some dynamic testing on a sunny day soon.

Just keeping you informed, please correct me if I’m wrong.

Yipster

Still thinking of the “how big” option 1 tread, a scalar engine, or maybe a “steam engine” as in the powerboats tread might make a big difference…

[Willallison]

Has nobody ever attempted to place some sort of a engine into a bulbkeel before in wonder?

Sounds great - low CG, very quiet etc - but how do you provide access for servicing and repairs? If the 'legs' are big enough to provide access, then they will have too much surface area - or the boat will have to be much bigger.....

[yipster]

quik service, easyer said than done i realise (but wouldnt it be nice!):D

[Willallison]

Like to see you engineer that one (at a reasonable cost;) ) and still leave room onboard for people moving about etc.
Plus you've put the engine at the front of the 'boat' - not too keen on that idea either!

Please don't take my criticisms personally - you just gotta convince me that the concept is viable in this size range.....

[yipster]

Thats why i asked -premature- for help. As a swath is a displacement, steel and weight wont be a problem i assume.

Got 1 model hull sandpapered. Got to do the mold than the 3 scale hulls. For testing weights and behavior have to fix 3 of those together, think of ways to propel or tow and wait for a warmer day.

I've recently seen small sloops having the eng. up front and a hydrolic (seems to become populair and chieper?!) powered -rear-prop. And why shouldnt a prop be placed all the way up front? All that is still open in my mind. Must confess that the drawing above dont have that leg tapered as i like. But many things are still to be figered out.

The swath concept i like, unlike a hydrofoil it can -but not that fast- cruize at any speed, having good economy and ride at the same time. Its using its own constant trick on mother nature doing that.

In my opinion well worth giving it a try. But please do stay critical!

:) yipster

[Willallison]

As a swath is a displacement, steel and weight wont be a problem i assume.


I'm only hypothesising here, but I can't see that just because you use SWATH, weight doesn't matter. No matter the hull configuration, the weight of the vessel is equivalent to the mass of the water displaced - the heavier the boat, the more water it will displace. In the case of a swath, a heavier boat will require bigger floats / pods / whatever you call them, or it will simply sink deeper until that equivalent displacement is reached.

In fact with swath, I'd have expected that as you're trying to minimise wetted surface, weight would be a major issue - but probably not as great a concern as variations in weight between light ship and full load conditions.

[yipster]

I am a little bit disappointed that only a few are sharing some thoughts on other boat design ideas. I would have expected at least some catamaran plans or other design ideas here in O2 but maybe that is still to come. I’ll keep talking swath ok?
I'm only hypothesising here, but I can't see that just because you use SWATH, weight doesn't matter. No matter the hull configuration, the weight of the vessel is equivalent to the mass of the water displaced - the heavier the boat, the more water it will displace. In the case of a swath, a heavier boat will require bigger floats / pods / whatever you call them, or it will simply sink deeper until that equivalent displacement is reached. Its good to be critical, but swath isn’t a max. load design. Calculating some of your questions is easy and may convince you better than I can. I did not say weight doesn’t matter, I said a swath is a displacement boat with a constant all speed range “trick”. It’s not like a hydrofoil, wig, cat or planning boat design. But maybe the keels and/or floads must be bigger, that’s possible. Its not so much the WSA as it is the SWA (small waterplane area) that makes a swa(th) very interesting. Its not “my” swath either since all sorts of early SWA patents are way back. What I’m aiming at isn’t even a true swath, I’ll like to mix it with tapered legs that more submerged come in as ama’s. The “floads” use a little foil action etc. All still to calculate, model build and test. Now making the model floats / pods / whatever you want to call them I have to use double moulds (and sealings) design a legframe inside etc. and I fully agree it is more complicated, expensive etc. but also see great gains. Calculate the difference between wave and wsa drag in a broad speedrange and you’ll see! Got a –still to add- formdrag formula for me? I’m back to sandpaper.
:) yipster

[yipster]

The poly shell of the first half leg came off real nice. :) As discussed in the “scratch build models” threat this “model” is now for a (2 pers) water bike. :D Displacement of one complete leg should be 80 liter. 3 legs would carry 240 kg. Weight can be added easy, buoyancy not. For a whistle I got a 30 kg 7.5 hp mercury outboard with worn out :mad: short :mad: shaft bearings. Must be repaired and plan to mount it on the backside of the front leg. With a high pitch prop I only hope its enough to make some speed. :confused: With pipes :eek: making a plm. 3 meter flat A frame (wont torque) to mount the legs on. Want to keep the front leg vertical adjustable to change the angle of attack, balance a seats basket on the bar :p and allready asked my wetsuit :rolleyes: back. A pic of half a leg I’ll post later. Still far from testing and only wondering about behavior. :) yipster

[Willallison]

Gotta hand it to you Yipster - you sure don't muck around do you!
How about posting some pics in the Gallery of the buil as it progresses....

[yipster]

thanks will, its sort of work do! http://www.conceptboat.com/ i found elsewhere in the forums, think i''ll enter that competition (who else is designing?) with "my" swath. foto's follow. :) yipster

[Willallison]

I was going to enter last year - but couldn't find the time in between my Westlawn stuff. Might have a go this time around....

[yipster]

at http://www.boatdesign.net/gallery/showphoto.php?photo=733&papass=&sort=1&thecat=506 a pic of my sandpaper work. what a joy it must be to have acces to a 5 axis foam miller plotter, 3 axis can even be great i imagine...

[yipster]

t(w)o difficult questions..

1e
the advantage of having a single prop outboard on the forward leg has the theoretical advantage of easy steering. by cornering fast (>40 knots) i get doubts on heeling on this non-liniar design. does anybody know how this may have been solved before? maybe better to have (also) horizontal rudders on the stern legs or what?

2e
wsa power, as ther is only a minimal wavedrag, is hard to calculate. 3 torpedo shaped pods of 100 kg displacement would need what sort of power to reach what sort of speeds on what economy? i know i'm asking a lot, than again, i promise cookies when this wins something in the http://www.conceptboat.com/ competition. :D

yipster

[yipster]

amazing diagram for this 3*100 kg/liter displacement isnt it!
friction/wsa resistance is very much lower as wave drag here.
the questions above i'm working on and have one more here:

the horizontal A frame that must hold the legs on the corners might not torque, made from aluminum pipes it may bend and swing. a carbon frame easely sets me back a grand i figger and may bend as well. maybe wise to extrude the A in the way the pic shows?
:confused: yipster

[yipster]

From the wetted surface area you can use the ITTC formula:

cf = 0.075/(logRn - 2)**2

where rf = 0.5 rho v**2 S Cf

--------------------------------------------------------------------------------
from the forum on "the society of naval architects & marine engineers" sname (http://www.sname.org/forums/committees/vessel/messages/98.html) i'll get more worry's: "this tri-cat is close to some existing notable designs, please caution!!"

i am not aware of that and only hope my designbrief in total is an original swa concept. if its within the concept boat competition rules (have to check) i'll post my designbrief and drawings here as i go along...

yipster

[yipster]

now having the formulea i did a quik search and found at: http://www.maths.adelaide.edu.au/Applied/llazausk/hydro/kayak/sea/skmag/skmag.htm (where else!) the same calculation with more info (on Small Sea Kayaks). wsa for my project is aproximately 3*2 squared meters, and i wil do a better measure tomorrow before applying the maths. havent even looked if it's a only wsa to how much power calc, but thats again is in MikeD's WSA thread i remember. now also want to check how deep wave resistance effects the streamlined pods in this design as was pointed out to me at the sname forum... (may have to extrude the swa area on the legs :mad:) but first a shower and the dust away please!

[yipster]

hi all,
offcourse wavedrag only goes as deep as the situation but cant find info on it.
did find a pic of pods that probably illustrates why propulsion is good but to engineer that...

[yipster]

roll causes a turn here, submerged pods will do the same but how much aileron, how to counterweight, hinge, or predict results. i realize this motor waterbike holds plenty of promises to disappoint, than again when all these challenges are addressed and solved it could be just great (i hope) brief and drawings i'm working on and are following to be evaluated / criticized.

[yipster]

Nicer drawings still to make when I can hold my pencil again, but here a lot of text intended to send pretty soon now to www.conceptboat.com where you can read terms and conditions I’m trying to meet. my thanks here for the advice i had and think its ok if used some of the quote's. still more help wanted: When one spots dumb mistakes and/or thinks an initial design brief should be completely different please let me know!

yipster

____________________________________________________


This 2 people SWATH like waterbike design can perform on a 15/20 hp OB >40knots
speeds in all weather and respond like a far larger boat.

As new speed limit regulations for inland waterways came, smaller speedboats became
almost unusable. On most of the calm inland waters are now speed limits, going to free
bigger lakes or sea was necessary but those boats are to small to make speed even in
moderate chop. This design makes it possible for a small craft to make speed in open
waters where small speedboats can only do so on windless flat-water days.

Unlike planing boats, hydrofoils etc. a SWATH (Small Waterplane Area Twin Hull) is a
displacement design that can make good speed also, this without repositioning itself and
keeping good economic propulsion all throughout its speed range.

The formulae WL^0,5*4.72=Speed (metres) or: 1.34*sqrt WL=Speed (in knots and feet)
when split into separate calculations for WSA and WAVE drag shows that resistance on
WSA is very much lower than WAVE drag for this design. Having a very good block coefficient the WSA drag only takes over from wave drag at speeds of 40 knots and more.

In this concept 3 pods under tapered small strut's form a SWA (Small waterplane Area) that reduces the heave stiffness in immersion and cause only little excitation of the vertical
motion. Thus a concept that is almost insensitive to waves, expected to be stable under
rough conditions and keeping these characteristics (like 3 torpedo's) even going fast.

I am now building a prototype to test and tune. approximately 5 meter length, 4 meter
beam, 0.65 meter draught. Volume displaced is 320 litre. Light weight mass is an
estimated 120 kg, full load 320 kg. The metacentre will be a bit high and react like a slow
piano clock like in sailboats, but is close to the centre of mass. Wide standing SWA legs
are giving progressively more buoyancy by submersion and accept 75 cm waves with a
slow max. 15 degree heel response and have on their topsides amas for direct righting.

Underway the airfoil shaped pods damp out the craft's own vertical resonance. The pods
can be water ballasted to change the crafts behaviour a bit and get the best water level
when being short loaded. Inward heeling behaviour in cornering is achieved on the stern
pods with ailerons connected to the steering. The propeller on the forward leg has the
theoretical advantage of easy steering. This front leg is now vertical adjustable to find the
best angle of attack. The lightweight non-torque triangular A frame construction and
clamps are modified stock aluminium scaffolding and ladder parts intended to be fit easily
together on the waterside making the need of a boat trailer obsolete.

A variation on the theme can basically be applied to bigger boats. Retractable legs would
than keep the size of the boat attractive for narrow inland waterways, shallows, berthing
etc. In a bigger design I am studying what hydraulics than might mean to the out-folding
legs and transverse bending, for propulsion etc. Building cost would probably be more
related to construction than overall size or power.

Down sides of the designs are that the payload must be centered leaving a large deck. The craft will not be well suited for long or large heeling or pitching moments.
Bigger and seagoing craft must be structurally very well designed. Manufacturing is more
sophisticated, than again, so will be the result I guess.

Purpose for this craft whose mission is giving fast and stable all weather performance:
big and small recreational, coast guard, maybe even a round the world record attempt?

I believe my design to be original but it is based on the SWATH principle. A Small
Waterplane Area however is a natural phenomenon; nevertheless I believe -like for other
designs- its safe to check patents anyway.

To do: give name, drawings, entree form, list, calculations, graphs, construction details,
pics, etc. For more info on this entree also see "yipster" at <http://www.boatdesign.net>

[yipster]

:cool:spiraling...

[yipster]

in the ppreliminar designbrief above i used a bit to much of stability "terminologragy" and -sorry- some was wrong, i have to provide "stability and buoyancy" characteristics. now reading some more on the subject i come to the conclusion its the CG and shifting CB under heeling. here a nice sample stability pic i found but none of the demo's i try'd accept "pods" or "non-liniair triangle" in its hydrostatics so i'll started estimating it the DIY way, see below. no lever arm (GZ) or ratio of righting moment to displacement yet, but when study'd i might just find out about that and my block coefficient (Cb) too :D any advice or comment?

[yipster]

ehh, stability i understood that must be taken from "light weight" or "without people"? first real attempt to find the stability characteristics on this waterbike, but with our without people it makes all the difference :eek:

[yipster]

I do now understand the stability geometry and its sum in meter/kg torque by varying heeling degrees
http://mywebpage.netscape.com/TedsSailingPage/ballast.html
Good and simple explanation on stability, just haven’t figured out why in the 45-degree heel pic the weight is suddenly 550 lbs for CG1. Mayby a mistake between CG1 and CG2? Anyone here with an even simpler metric explanation, calculation or software hint please reply. 2 other sites I found with good info on stability:
http://www.ghsport.com/left/software/hsframe.htm most interesting article but no calculations
http://www.nadn.navy.mil/NAOE/courses/en200/ch03.pdf the elaborated math’s.

[yipster]

advice/comment? i'm open!:D

[yipster]

why do i like the rough above better than this last drawing?
http://www.boatdesign.net/gallery/showphoto.php?photo=846&size=big&password=&sort=1&thecat=

[Guest]

They're both awesome drawings!

Unfortunately, I don't see that kind of boat every day (err, or ever for that matter) so I can't offer you much in the way of intelligent comments.

But the drawings look very interesting, especially the smaller version.

[Guest]

In the above sketch and this drawing: http://www.boatdesign.net/gallery/showphoto.php?photo=843 doesn't the outboard get dunked when the boat is at rest?

[Guest]

P.S. And I love the styling of the above drawing and the one at http://www.boatdesign.net/gallery/showphoto.php?photo=843 because it reminds me of a roadster, or like the prowler styling... but on the water :)

[yipster]

Glad to hear you likes my ramblings and it does not hurt to get a compliment once in a while. You are rite that the outboard may hit the bottom coming to a stop in shallow waters but so would a planing boat. Non-electric starting wont be very handy I see and I’m only still guessing witch way the craft will go steering only the ob behind the front leg. If it will try to encircle it like a stern ob than the trust vectoring and heeling will be good. Got a reply on hydraulics that sounded most promising for the bigger design but hell, rite now I’m only a starving dream boat designer. Hope to have this water bike ready this summer tho, check the theory in practice, test and tune and get a better feeling of the trade offs in this concept. :) yipster

[yipster]

my first GZ here, no books yet, is that the way its done? i know, it should be in excel (still dont know what "GZ" means!) the starter pully on my OB can be turned 180 degree (and a hole in the cover backside should solve that). started toy (boat) testing by framing 3 toyboats together and put only a battery in the first, on my way to the bathtub now for tanktesting :D hope that'll be without brain dammage :D i talk to much :o
http://www.boatdesign.net/gallery/data/500/690Y14mG.JPG

[yipster]

Strange encounters in trust vectoring dynamic bodies.

When steering a (stern mounted) OB on a monohull the boat actually goes another direction as oposite to the prop’s trust because the hull works as a rudder up front. The prop also try’s to encircle the beam vertically when cornering, thereby creating inward heeling.

On fast catamarans 2 canted OB’s (i want those!) can do the same job on heeling, but that may be too much for a mono hull. Making it more complex by putting the OB on the bow -for the sake of the argument- the boot will simply follow the OB but give NEGATIVE, OUTWARDS heeling! Ok, it might take the bow wave away but that’s another story.

I started wondering what will happen with the water bike design having the ob behind the front leg, wasn’t so sure if it would encircle its front leg or -due to the rear legs drag- follow the engine. That means wasnt sure it go left or right, heel in or out.

So I made another model, fairly accurate this time. Got a small RC outboard on the back of the front leg and guess what happened? From stationary it follows the OB and heels a little out, not good! But when getting only a little on speed it starts encircling the front leg going the other way (without steering) and give the rite inward heeling!

Must be strange going slow steering opposite! I wont be the last shooting my own balloons down and guess I’ll better finish the real thing and call it “test model”. Making the new waterbike model I again realised how precise a swath concept must be. Strange encounters in trust vectoring may turn out the smallest of problems / challenges…

[yipster]

http://ness.external.lmco.com/nessb/photos/cool_stuff/models/seaslice_kit.gif
in my search for a swath VPP i came acros lockheed martin marine systems (http://ness.external.lmco.com/nessb/ship_systems/platforms/challenge.html) its popular reading on swath / slice but no real WSA VPP or 3D units in the drawing above, witch looks like fun tho :D

[yipster]

ok, seriously, i'm back on the (water) bike, could not help my eye fell on this 14 page .pdf paper:
Optimal Design of Thruster System for Superconducting Electromagnetic Propulsion (http://syd.mech.eng.osaka-u.ac.jp/papers/1994/05_IMDC.pdf) by: Shinsuke AKAGI, Kikuo FUJITA and Kazuo SOGA who investigated this superconducting truster on swath pods, propulsive efficiency is still to be improved, (sea water has a low conductivity) but i just wanted to let ya guy's know, i got to hurry or i am getting old... "time" the rabbit said asking for half a cup...

[yipster]

Wow, a one legged HYSWATH eek eek who dreamed that one up, great! (see demonstration at http://www.mapcorp.com/page4.html with thanks to Steve) Have -bla bla- that leg “somehow” retractable? Feel a bit yesterday’s paper now with my trike. Got the legs about done, making the ailerons now. Would it be allowable to have a cable only for the ailerons upward motion that pulls the leg down or is it going to swivel wildly?

Getting technical reactions (with or without sending my drawing) for a quote from the scaffolding, aluminum, stainless and steel trade here is almost hopeless. Yes they like the drawing but I had thought they could give the necessary strength estimates (like at http://www.efunda.com/formulae/solid_mechanics/beams/casestudy_display.cfm?case=simple_2symload with thanks to MDV for the address), confirm steel ads 40% weight on ali, diameter to wall thickness advice, pipe weight, advice locking systems, at least get the concrete sizes to figger the sleeves and a price. Not so! the few pipes I need are probably financially not interesting to them anyway.

On the net –and here on boatdesign- is more info! It made me think of some 80-page manuals for building a 2-sheeter rowing boat is no joke! Now I see that in reality it actually does make a lot of sense to calculate and detail in advance! That design spiral counts to the very last part!

Got a calendar but got too many open questions left that wiser be answered before pushing ahead to fast and goofing it up. So I’ll keep checking the piping industry here (and maybe reply’s on this mail?) because “ready in 2 months” should -without delay- be feasable! looking at the date, time fly's! yipster

but today i'm off to the beach, why not spy around a few cats :cool:

[yipster]

Hello all,
September now and must admit I’m slightly of scheme. It’s been a while since I updated this thread but last month my trike building came to a stop. Our sundancer had to return from France and now it’s missing its props. Otherwise the trike could have been in the water but propulsion needs an extra long shaft (and actually 15 to 20 instead of my 7.5 Hp OB). An extra long tail on a new OB cost 100 bucks more but having that conversion bought separate comes to 700. Pictured an electric drive but needs an external power source and only checking on these alternative’s recently. Anyone with fresh simpler ideas?

yipster

[Nomad]

Can't wait to see some finished Pictures and specs!!!

[yipster]

i can only second that and thanks for the interest.
the sundancer is in the water and hope doing some tow testing with the trike soon. propulsion i'm searching for. ah, and dont forget to make a seat, wheel, cables etc. what looks so easy is still work and money, havent given up tho!

yipster

[yipster]

hi all, broke but now getting some insight in the mercruiser EFI setup. so the trike has to wait a little longer. was reading the tunnel boat news letter and it had a rather interesting article on OB torpedo drag. you all probably allready read but if not, here the article "How does a tunnel hull work? (Part 4)". for more info contact jimboat below or here on the forum.


We have had many requests to explain each of the many factors that can influence the performance of a tunnel boat. There are literally dozens of factors that have an impact of performance, and most all of them influence the other factors. This makes the prediction of tunnel hull performance a tricky business - to maintain the inter-relationships of all of these factors throughout the operating velocity range of the boat. The good news is that most of these factors are controllable (by design and setup). We usually rely on computers, and the advanced "Tunnel Boat Design Program" (Version 7 now released) to do the hard work for us.

In the last three TBPNews letters, we looked at the factors that influence performance resulting from lift & drag relationships, thrust relationships and the location of weights & measures influences on performance.

This week we will look at lower unit design and the influences on performance. The optimum setup of your gearcase can create a gain of 13 hp at 100 mph! Read on to see how!

Much can be done to optimize the balance of all the forces acting on the tunnel boat in motion. This balance can be achieved for a range of speeds at the design stage, by optimizing the location of the forces involved. By selective designing of all the aerodynamic and hydrodynamic surfaces that become critical at high speeds, each tunnel hull can be tuned at the design stage. It is important to do this "dynamic balance" at all speeds through the boat's operating range - since balance at one speed just is not enough! (So balancing your boat on the trailer, by moving weight around is only going to help if you boat never leaves the trailer).


"Appendage" or motor drag. This component is not easy to calculate in a simple manner, since there are so many different designs of outboard lower units in use today, and since every boat will have the loser unit set up with respect to the hull just a little bit differently. The chore of analyzing such a 'beast' can be split into the parts of the lower unit, that is - the skeg, the torpedo and the propeller. Here's some of the design measures that we have control over:

* Lower Unit Height - Height of lower unit "bullet" above/below sponson running pad. (+) is above, (-) is below. Most high performance setups start with as little of the lower unit bullet in the water as possible, thus reducing drag significantly. Surface piercing propellers and low-level water pick-ups make this feasible. Normally, values of +0.5" to +1" (above sponson running surfaces) are possible in very high performance applications. Without low water pickup, or when low-end torque is a requirement, then LwrUnitHeight values of -0.5 to -2" (below sponson running surfaces) is applied.
* Lower Unit Drives Quantity - The number of lower unit drives (no. of engines) will impact the hydrodynamic drag generated at all speeds. It is a design trade-off as additional propeller thrust of multiple drives can reduce propeller slip, increasing overall efficiency.
* Skeg Width - average width of motor lower unit/outdrive skeg (leading edge of skeg to back of skeg). The Skeg is really just a kind of wing, flying through the water - sideways. It can be analyzed as such, using traditional aerodynamic approaches. It affects the friction and induced drag generated by the lower unit.
* Skeg Length - length of motor lower unit/outdrive skeg (top of skeg to bottom of skeg). Also affects the friction and induced drag generated by the lower unit; but on the positive side, longer skeg can provide better stability and handling under high load conditions such as cornering.
* Skeg Thickness - Thickness of motor lower unit/outdrive skeg (thickness of the skeg plate). It affects the form, friction and induced drags generated by the lower unit. Only reason for "thick" skeg design is a structural or reliability one - thinner is better.
* Torpedo Length - length of motor lower unit/outdrive torpedo housing (leading edge of torpedo to aft edge of torpedo, at prop shaft). The 'Torpedo', or the part of the lower unit that houses the transmission, etc., is really very well described by it's colloquially used term - torpedo. This part is actually just a projectile moving through the water, usually generating 'zero-lift' - just drag. The longer torpedo is better, as it will have a higher "aspect ratio" thus generating less induced drag. After-market nosecones are used for exactly this purpose, presenting a more stable water flow over the torpedo length, reducing drag and reducing propeller burning or blow-out.
* Torpedo diameter - diameter of motor lower unit/outdrive torpedo housing (in cross-section). Affects the form, friction and induced drags generated by the lower unit. Only reason for larger diameter design is a structural or reliability one - smaller is definitely better.
* The Propeller of course, is a multi-aerofoil component generating lift and drag in all different directions. (One of these directions we call thrust, and we use it to 'propel' our tunnel boat). As far as additional drag on the hull however, the propeller contributes very, very little and so we can ignore it!

The total drag of the motor then, will be determined in a very general way, based on the velocity of the hull, and the 'type' of outboard motor lower unit used (i.e. size of engine, stock/racing unit, etc.)

Height of gearcase makes a difference. A typical Mercury Sportmaster gearcase at 60 mph velocity, with the torpedo positioned exactly at the trailing edge of the running surface (height = 0) can have about 34 pounds of drag. If the gearcase was 1" lower in position (1" below the trailing edge of the running surface, or height = -1") then we would generate 43 pounds drag - that's over 6 HP worth of drag! The same gearcase at 1" above the trailing edge of the running surface (or height = +1") would however, have only 25 pounds of drag at 60 mph. And think of that gearcase setup at 100 mph - it will create 112 pounds (30 hp) of drag at height = -1"; and only 64 pounds drag (17 hp) at height = +1"!

As we explained earlier, the motor drag can be a very long and tedious contribution to calculate in detail. This drag is made up of the drag on the 'skeg' on the lower unit, and of the drag on the 'torpedo' itself. Naturally, the size, shape and length dimensions of both the skeg and torpedo, as well as the velocity of the hull, will influence their relative contributions to total drag.

The actual details for calculating such contributions are complicated, and really outside the scope of 'hand-calculations'. With the use of Computer-Aided-Design programs, we have reduced this calculation process considerably. To save a lot of time, we will try to 'standardize' the characteristic hydrodynamic drags of the popular outboard engine lower units available and currently in use on tunnel hulls.

The smaller stock outboard engines can be categorized into one group of say less than 50 Cubic inch displacement (cid) to establish a group of similar lower unit characteristics. The engines larger than about this size, even up to the engines with displacements greater than 125 cid, can be categorized into another group of stock engine sizes. Two additional groups are represented by the Racing versions of these engine sizes, since the dimensions, shape and size of these lower units are substantially different again.

At AeroMarine Research, we use the "Tunnel Boat Design Program(c) " software to make the analysis easy. The TBDP calculates all hydrodynamic and aerodynamic lift forces by all lifting surfaces, all drag contributors, and does a dynamic balance of the hull at every speed defined in the performance specification. Doing this all in seconds makes it very easy to make small changes to the hull design, power or setup, and to determine the effect on performance and stability. We use the "PropWorks2(c) " software for propeller selection and speed prediction. Whether done manually (as shown in the "Secrets of Tunnel Boat Design" book, or by computer with TBDP, designing a tunnel boat that will optimize performance and ensure stability is possible when we understand how these factors influence performance and stability.

Well, that's enough for this issue - and this is the end of this series of articles. I hope that we have seen the major areas of design control that we can concentrate our design efforts.

See you next time!

/Jimboat

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>>>>> Tunnel Boat Performance News >>>>>>>>>>>>>>

Let us know any ideas you have, requests for articles, questions or comments on our TBPNews. Send your comments to TBPNews@aeromarineresearch.com
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

Get your full, illustrated, NEW 12th edition copy of the world known "Secrets of Tunnel Boat Design" book. GO TO: http://www.aeromarineresearch.com



in time i'll get the books, software etc!
:D yipster

[Guest]

Did you ever find any one who used a gas engine in a keel bulb?

[yipster]

Guest,
i belive MAPC (http://www.mapcorp.com/page4.html) has its (diesel?) engine in the bulb? and i've seen a few other, it's interesting and can be done but is certainly not the easyest setup...

[Guest]

Yipster:
I am toying with the idea of making a remote control torpedo sub. the smaller the engine the better.

Do you have a rough idea of how fast 100 hp would be able to push a 16" wide wave piercing torpedo.

[yipster]

you want to do that remote? not with a warhead i hope! and why a fast wave piercing torpedo that will hit wavemaking resistance, going fast the idea is to get out of that i belive?
see http://www.users.globalnet.co.uk/~fsinc/yachts/spreads/fred.htmand you can also use the search button here and check for "froude" or "resistance" for much more on this.
i did check submerged torpedo speeds versus HP and found a high curve diagram. here some not so easy to find info.

from another forum:
>yipster:
>>how much power / hp is needed to proppel a torpedo? who can help?
>I. Yes. Need dimensional info not here. 300kg not important unless vehicle "planes" (under/over water).
>It depends. Need info. Cyl Diameter, Length
>Drag Force = Cd.. * SomeArea * 0.5RhoV^2
>Wetsurf + Form + Wave + Lift-induced(not here - planing only)
> wsa; profileareas; L^2, shape factor; Liftarea
> consts consts consts consts
>Appropriate references for Cd....

A typical 21” (533mm) steam torpedo produced upwards of 300hp to achieve its maximum speed, usually around 45 knots. Many also had lower power settings available to achieve longer range. The Japanese Type 93 had what was probably the most powerful engine in a WW2 production torpedo, producing over 500hp. Aerial torpedoes usually produced about 150hp, good for about 40 knots. exception was the USN Mark 13, which produced only 98hp, good for about 33 knots.

http://uboat.net/allies/technical/fido.htm shows 12 kts on 5 hp for 680 lbs (=approximately 45? squered ft / close to the displacement of the waterbike design

Torpedo MK 24 - "FIDO" The First American ASW Acoustic Homing Torpedo
Size: 19" dia. x 84" long
Weight: 680 lbs.
Propulsion: Single propeller driven by a 5 HP electric motor-48 volt lead acid battery
Speed and Endurance: 12 kts for approx. 15 min.

at http://uboat.net/types/schwertw.htm another WSA sample going 30 knots but don’t say how much WSA or on how much hp/kw

The US Mark 14 ran at 46 knots -- some current models are reported to do as fast a 60 knots

here some hard to find links i collected, not sure if they are all still active.
http://www/warships1.com/Weapons/WTBR_WWII.htm
http://www.warships1.com/Weapons/WTJAP_WWII.htm
http://www.warships1.com/Weapons/WTRussian_WWII.htm
http://www.warships1.comWeaponsWTGER_notes.htm
http://www.diodon349.com/torpedoman/TM_Stuff.torpedoes.htm
http://www.militarism.navy.ru/torpedoes.htm
http://www.geocities.com/Pentagon/1592/ustorp1.htm
http://www.geocities.com/Pentagon/1592/ustorp2.htm
http://www.geocities.com/Pentagon/1592/ustorp3.htm
http://www.regiamarina.net/index_it.htm
http://www.geocities.com/Pentagon/1592/ustorp3.htm
http://www.geocities.com/ssvong/submarine/molch/torpedo.htm
http://www.dataphone.se/~ms/ubootw/torpedoes.htm
http://www.weymouthdiving.co.uk/torpedoes.htm
http://www.weymouthdiving.co.uk/torpjist.htm
Japanese Torpedoes: http://www.skypoint.com/members/jpb.torps.htm
Russian Torpedo Armament: http://www.militarism.navy.ru/torpedoes.htm
http://64.124.221.191/torps.htm) has a good primer on IJN torpedoes www.warships1.com.
http://www.j-aircraft.org/bbs/jship_config.pl?read=11800

[yipster]

from the "a question on drag" thread:

Apparently "boundary area bleeding" would have been a better terminology for what I was trying to express above. Could this also be referred to as "induced cavitation"?

ref:
http://www.usc.edu/CSSF/History/2003/Projects/S0101.pdf
http://www.curj.caltech.edu/archives/vol1/1004005.pdf

Doug Carlson


Doug, thats very high speed! 230 mile hr torp's and supercavitating passenger submarines that could cross the atlantic in less than an hour! from caltech! makes me wonder where they plan that crossing. reading edmund pope's story i wonder if i dear mentioning a new water repelant boat paint that couses cavitation and should reduce resistance dramaticly?
yipster


its a pitty the http://www.curj.caltech.edu/archives/vol1/1004005.pdf paper went ofline, hope it gets back without the wargames talk? very fast torpedos i heard of before but its sort of hush hush top secret. on whatever propulsion it still must be amazing friction reduction tho, perhaps start a new thread on it as Doug suggested?

yipster
http://thumb2.sac.overture.com/image/434986470

[Doug Carlson]

Yipster,

Here in the US they have been running a TV commercial for a luxury sedan, Mercedes I think, that has its underside sheathed in dimpled material to reduce wind resistance (read surface friction) and noise.

Doug Carlson

[yipster]

Doug,
thanks for that info. i've been watching all european tv commercials for a while now but havent seen such dimpled surface materials other than on golfball's here yet... the tv spot is remarkable!
it was a thought and in boating is probably subject to other conditions, who knows?
meanwhile i learned that state of the art CFD programs wont input / handle this anyway yet but sure are interesting as well.
real high (submerged) speeds -and there is enough reason to belive- i can only wonder about and guess your thoughts are as good as mine; air ventilation and boundary area bleeding and?
dont expect getting the answers soon though.

keep me updated
yipster

[Doug Carlson]

Yipster,

In the Boat Design section of this forum, there was a recent discussion of Hickman sleds, inverted "V"s, etc. "Trouty" posted a reference to a "Bream" fishing forum. If you go there, "badge68", the Inverted V guy from this forum, has some comments.

This is a quote from one of his posts:

"the whole concept of the IVB is getting airrated water next to the hull to reduce skin friction..
there is about 1/2" layer of white water air/water mix coming out from the transom when under way at speed.
the hull currently requires at least 20% less HP to drive for a similar length mono hull (even with larger wetted hull surface)"

Seems relevant to our discussion also.

Doug Carlson

[Doug Carlson]

Yipster,

The car with a dimpled bottom is a Lexus sedan.

Doug Carlson

[yipster]

nice car also! started wondering why some stuff fascinates me so much while it barely has daily practical use for me, seems you got the same disorder? in a earlyer posting "formdrag", i recall mentioning that golfball allready and yesterday on tely i hear: "the dimples in a golfball make for a smaller wake couse the boundery layer sticks better and further afterwards witch also improves a straighter trajectory. so a dimpled golfball fly's twice as far as a smooth one!" impressive! ok, thats a golfball and a boat isnt a ball nor does it fly (actually some do) for the lexus carbottom however it seems to work as well. offcourse one could say its harder to clean etc. but i find it interesting...

reading on Lippisch i came acros some info (http://www.flightjournal.com/articles/me163/me163_6.asp)on supersonic surface flow, wonder if a mach nr. can somehow be compared with a froude nr.?
As air flows over an object, it changes speed. In near the nose, the air is slowed. Further aft, where the air is accelerated, the local airspeed is actually higher than the speed of the airplane. As the speed of the airplane approaches the speed of sound, the local flow will go supersonic on some parts of the airplane.
crazyest of all may be some of these designs used coaldust for fuel :eek:

[Doug Carlson]

Yipster,

Speedo the swimsuit manufacturer just announced their latest supersuit for the Olympics. As before it mimics sharkskin. Apparantly it has "rivlets", (corrugations, I think) of differing configurations to increase and decrease resistance in areas of high and low pressure that result when the inconvenient protuberances that human beings exhibit are dragged through a fluid.

Doug Carslon

[yipster]

Doug,
yes i wear speedo day and night and have seen special surface suits for biking and skating, for swimming its new to me and makes sence allrite. guess we wont swim twice as fast in it? maybe when exhaling air trough cavitating hotspots in the suit witch probably isnt all that easy or within the rules. the caltech article on super cavitation (http://www.curj.caltech.edu/archives/vol1/1004005.pdf) came online again, now thats real speedo and i saw you drew up some real smooth lines (http://boatdesign.net/forums/showthread.php?t=3236) in Pro/E, well done! I recently got exited over H2O; split its clean powerfull energy (like all the world allready knew i found) still it occurred strange to me ships and boats only sail, not use that possible potential. i planed a visit to an open day from a local high flux research reactor and intend to learn more about neutrino's, the real original and in H missing neutron, but financially i only qualify rite now for olympic barrel rowing.

[yipster]

Doug, little late but thanks for the 3d -and a ½- plotter explanation, only have a hand held router I seldom use and although fascinated by cad cam the most I ever did was plug in my girlfriends knitting computer.

Know what you did mentioning "laminar flow", I haven’t slept since. Only now http://www.grc.nasa.gov/WWW/K-12/airplane/boundlay.html I fully realize in wsa drag the touching liquid layer actually stands still.
http://www.grc.nasa.gov/WWW/K-12/airplane/Images/boundlay.gif
This site has lots of interesting info http://www.grc.nasa.gov/WWW/K-12/freesoftware_page.htm Saw on telly some perforated planes suck hotspot flows away where boats may perhaps ventilate air. Here some more info on wsa super cavitating 500km hr torpedos: http://www.diodon349.com/Torpedoman/TM_Stuff/shkval_torpedo_links.htm I’m a pacifist but hell; I sure am fascinated by technology.

Glow discharge plasma for example http://jlnlabs.imars.com/plasma/images/fairystar_s.jpg http://jlnlabs.imars.com/plasma/html/s_gdpthr1.htm
I also saw at http://www.grc.nasa.gov/WWW/AERO/base/images/rac.gif http://techreports.larc.nasa.gov/ltrs/PDF/1998/aiaa/NASA-aiaa-98-0328.pdf

Keeping things simple I found that boiling water not necessarily happens at 100c. Boiling requires seed steam bubbles, boiling water without bubbles can superheat above boiling point. In a magnetron superheated water can be dangerous, a tap on the container initiates violent or even explosive boiling. Why do the gasses H and O form a liquid, why does ice float on water plus a explanation how the water molecule and its electron configuration looks and more at: http://howthingswork.virginia.edu/supplements/water_steam_and_ice.pdf Aint no chemist -but can electrolyse- and when i hear Hydrogen (2 or 3 times more potential than regular) is now 3 times the price of conventional gas i'm sure the difference must be in storage, transport and tax. Oxygen and hydrogen atoms combined explode/burn at a high thermal 3000 c and form really pure water again. Hydrogen with air (instead of O) burns fair but does not turn to clean water again as we are made to believe at forexample http://www.ecotecture.com/library_eco/energy/hydrogen1b.html Still H or water probably is our near future fuel as fusion isn’t really ready yet. Looks like I found a similar electolyses idea in fuel cell wings at http://www.grc.nasa.gov/WWW/AERO/base/rac.htm but cant figger out what its for, is that an integrated distributed propulsion / power plasma drive or a surface drag reduction shield like mentiont above? Nasa is using the words hydrogen and oxygen more than I but boaters floating on water have a big advantage in this technology. Boats and ships as I see it don't need to store and liquefy H (deepfreeze to -253c) Boats should find way’s to get H and O out of the water we float in economically and use it immediately for propulsion simultaneously producing the fuel. Ok, we might need generator assistance but tricks like Kelvin’s thunderstorm for example can chance waters electron config and may make the electrolysis much easier, also http://jlnlabs.imars.com/mahg/article.htm and http://www.powerlabs.org/waterarc.htm gives plenty of thoughts on H and O production and consumption without the need starting a biological H algae farm. Long time ago farmers use to make natural gas and I guess on this sunny day I’m wasting time; Chrysler Mercedes and other conglomerates probably already have everything patented and I now recall a movie where an alien government came to earth stealing our water. Guess that’s more real than my steam engine thoughts. But yes, who else is as crazy, I am dreaming up some sort of pop-pop boat http://www.pursuitdynamics.com/images/MARINEP.GIF steam propulsion http://www.delphion.com/details?pn10=US06484491 perhaps pulsing or shock waving as http://www.pursuitdynamics.com/Marine.asp calls it. (water shows the shockwave but how about the bang?)

Summer is here, my wheels need work, maybe not directly boating but how can my good diesel bus get smooth in the exhaust and is turned down on the annual test? It isn’t using a drop of oil so what is coursing that sooth? "that’s going to be expensive, can be injectors, can be pressure pump, can be anything” is all I get. Boats don’t get that test yearly and may develop the same problem I assume? Is here a diesel expert with some more wisdom in the room that can explain, or is it too complicated and one better buy’s new?

The sundancer wants to the water but needs a duo prop, anti fouling, close the hot water boiler valve, diesel for heater can be later but its work and money. Looking at the half build swath trike here I want to try out I realize it wont be very fast and may cavitate the wrong way but I still believe in it, other features might just work amazingly well, got to do it but must admit I’m behind schedule.

I've got planty to do and have a –way to much- inquiring mind, wish I were rich and not so pretty.

PDF on hydrogen combustion :
http://www.ott.doe.gov/otu/field_ops/pdfs/fcm03r0.pdf
more links on request :cool:

[yipster]

o yes, i got mail from concept boat, their new competition is open till 30 june 2004 for entries that are a new design of recreational or commercial craft of up to 24m length, primarily focussing on their use in the environment.

i send a boat drawing that incorporates above :D

see 2003 concept boats and their discribtion plus this years info at www.conceptboat.com

[yipster]

Evidence Bubbles Over To Support Tabletop Nuclear Fusion Device on "super" cavitation.


(with thanks to Mark from the http://www.pulse-jets.com/ forum)


from http://www.spacedaily.com/news/energy-tech-04o.html

Researchers are reporting new evidence supporting their earlier discovery of an inexpensive "tabletop" device that uses sound waves to produce nuclear fusion reactions.
The researchers believe the new evidence shows that "sonofusion" generates nuclear reactions by creating tiny bubbles that implode with tremendous force. Nuclear fusion reactors have historically required large, multibillion-dollar machines, but sonofusion devices might be built for a fraction of that cost.

"What we are doing, in effect, is producing nuclear emissions in a simple desktop apparatus," said Rusi Taleyarkhan, the principal investigator and a professor of nuclear engineering at Purdue University. "That really is the magnitude of the discovery – the ability to use simple mechanical force for the first time in history to initiate conditions comparable to the interior of stars."

The technology might one day, in theory, lead to a new source of clean energy.

The device is a clear glass canister about the height of two coffee mugs stacked on top of one another. Inside the canister is a liquid called deuterated acetone. The acetone contains a form of hydrogen called deuterium, or heavy hydrogen, which contains one proton and one neutron in its nucleus. Normal hydrogen contains only one proton in its nucleus.

The researchers expose the clear canister of liquid to pulses of neutrons every five milliseconds, or thousandths of a second, causing tiny cavities to form. At the same time, the liquid is bombarded with a specific frequency of ultrasound, which causes the cavities to form into bubbles that are about 60 nanometers – or billionths of a meter – in diameter. The bubbles then expand to a much larger size, about 6,000 microns, or millionths of a meter – large enough to be seen with the unaided eye.

Within nanoseconds these large bubbles contract with tremendous force, returning to roughly their original size, and release flashes of light in a well-known phenomenon known as sonoluminescence. Because the bubbles grow to such a relatively large size before they implode, their contraction causes extreme temperatures and pressures comparable to those found in the interiors of stars. Researches estimate that temperatures inside the imploding bubbles reach 10 million degrees Celsius and pressures comparable to 1,000 million earth atmospheres at sea level.

The desktop experiment is safe because, although the reactions generate extremely high pressures and temperatures, those extreme conditions exist only in small regions of the liquid in the container – within the collapsing bubbles.

One key to the process is the large difference between the original size of the bubbles and their expanded size. Going from 60 nanometers to 6,000 microns is about 100,000 times larger, compared to the bubbles usually formed in sonoluminescence, which grow only about 10 times larger before they implode.

"This means you've got about a trillion times more energy potentially available for compression of the bubbles than you do with conventional sonoluminescence," Taleyarkhan said. "When the light flashes are emitted, it's getting extremely hot, and if your liquid has deuterium atoms compared to ordinary hydrogen atoms, the conditions are hot enough to produce nuclear fusion."

[yipster]

So cavitation at your prop, the stereo loud and you might just be creating a fusion reaction at the stern without even knowing or using it

Buying fuel -here now E 1.30 a liter- for the purring efi merc’s may be a good thing cause I only made some small inexpensive pop-pop propulsion tubes just on butane gas heat. They work and I love the simplicity. Found this PDX cut trough drawing
http://www.newscientist.com/data/images/ns/9999/99993321F1.JPG at http://www.newscientist.com/news/news.jsp?id=ns99993321

Fueling my small pop pop steam jet with split water H2+O I didn’t try/dare yet. Did not calculate cost electrolyzing, haven’t even called our local gas depot but saw a 55 cent price (plus insurance) on H2O2 hydrogen peroxide at: http://www.tecaeromex.com/ingles/indexi.html

Offcourse all this may sound like Clarabelle Cow “if it wasn’t for Thomas Edison we’ll be watching TV by candlelight now” so making it easy I got new temp regulated computerized fuel injected lambda wheels. Were ever did I read that the internal combustion piston engine is a overdeveloped poor design? Little choice these day’s I guess?

[yipster]

H2O waterjet http://www.scitoys.com/scitoys/scitoys/echem/echem.html#bomb

http://sci-toys.com/scitoys/scitoys/echem/phb.gif
plants live from water, splitting oxigen out using the hydrogen, why cant we be so smart? more on hydrogen, a cost picture and more http://www.eere.energy.gov/hydrogenandfuelcells/hydrogen/faqs.html

[yipster]

who can explain a little what cavitation numbers are based on as mentioned in the caltech paper on supercavitation at http://www.curj.caltech.edu/archives/vol1/1004005.pdf and what free or lowcost software is there that gives insight in only computer fluid dynamics and potential multi flows?

http://www.boatdesign.net/forums/showthread.php?t=2821&highlight=cfd has good info on ship resistance but for a while now i wonder about propulsion like above. is it really so a waterjetdrive only work well having the waterjet just above the waterline?

from >4000 C burning H and O forms superheated steam, now how much more water wil that vaporise (water to steam is 30 times if i recall rite?) below that waterline, what was the name of those fantastic keramic spaceshuttle tiles again you can touch bare handed while heated above temperatures mentioned here, planty of real hard questions for just a hobbyist i know...

[yipster]

http://i.timeinc.net/popsci/images/space/space0903pulse_H.gif
imagine such a jet on water power, no need for a tank making hydrogen and oxigen directly from water, keramic pipes simplicity and underwater i guess the noise problem is solved. read more on the future jet at http://www.popsci.com/popsci/aviation/article/0,12543,473272-1,00.html
on a boat such a jet would fit best but doubt mercury, volvo or others will beat GE and pratt and whitney in R&D, in time however it looks like these will be our new engine's...

[Tom Taylor]

Yipster,

Keep up the good work! Your design work has inspired me. I've made some drawings (mere scribblings) of dreamcraft that are radical. I have no formal technical training and only design by feel (the seat of my pants). I look forward to building/owning one of your vehicles someday.

The submersion of the outboard/engine is something I've encountered in some of my designs. My thoughts on a solution to change direction,are: a) encase the engine in a watertight chamber that swivels, b) make the engine stationary and use a rudder system behind the propeller or jet or, c) encase the entire propulsion system in a watertight, underwater module with air venting from the surface of the craft.

The combination of hydrofoil, WIG, and hovercraft technologies is most interesting.

Best Regards,
NE Port

[yipster]

Tom, sorry for the late reply and thanks for the compliment! thats how i also consider designs; as if i would like to have them for myself...

on the watertrike wich was intended as "lowcost" test-out model i am looking into a "propulsion system in a watertight, underwater module with air venting from the surface" the 3 legs are made and need the horizontal aluminum triangle, its slow progres though. anybody quiker can take a shot at it, i too like to see those swat ideas tested!

surface effect ships are certainly interesting but i realise its hard to beat a regular setup that also eats money and i wont give up on. so how many waterbikes or swath's you want? just joking, i'm happy, keep drawing and do show the seats of your pants also! :D

[Larry Gudde]

{TICKYBOO} I like the inderwater layout, and would like to build one,. But need some kind of a plan. I have a complete machine shop and am a master tool maker.

[yipster]

{TICKYBOO} I like the inderwater layout, and would like to build one,. But need some kind of a plan. I have a complete machine shop and am a master tool maker.
yes yes the simple sample (http://www.scitoys.com/scitoys/scit...echem.html#bomb ) above taken horizontally gives ideas eh? great to hear more interest in it. i like the thought to split water, planty power there but forexanple H2 peroxide got planty power also and is used allready, but sunk the kursk -its dangerous!- however producing and using on site reduces the risk and gets away with transport and storage laws i think. a lot to talk we have. when back later today i'll place some more links and some better ideas on making such a layout (and prototype?)

some interesting plans but auction ended (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=2567&item=5921241514&rd=1#ebayphotohosting)
a hybrid pulse piston turbo .pdf (http://www.pulse-jets.com/phpbb2/download.php?id=1719)
amazing H2O2 power and more (http://www.meditech.ch/exoticthermoengineering/)

[yipster]

here 2 short interesting files on lifting body combined with hydrofoil technology for small coastal transformational ship design

http://www.navatekltd.com/papers/liftingbodytechfortsd.pdf
http://www.navatekltd.com/papers/VirtualAcquisitionShowcaseMay2003.pdf

[yipster]

article on supercavitation at http://www.freerepublic.com/forum/a397c938f46bc.htm
and a whole bunch of crazy boats at http://www.gizmag.com/go/3768/

[D'ARTOIS]

There are designs and later on made models of a keel-propulsion; i.e. a hydraulic unit that is placed in the bulb of the keel.

It never took off - for some reason.

[yipster]

jeff "collaboration" looks and sounds good but cant post under your thread "new option2 forum" were i get "This Thread is more than 854 days old, you can't reply to it."
i am a bit in shame over my swath bike project standing still for a few years now
one boat turns out to be allready a handfull, have mentioned it but say again:
anyone want 3 swath legs and promises to work on it faster than i do ?
http://www.boatdesign.net/gallery/data/506/690yipf.jpg

[zeevonk]

lol found some similarities

http://boatdesign.net/forums/showthread.php?t=10441

Please help me gather my thougts about the "trimarans with out of line hull configuration" problem.

[Wellydeckhand]

nice design....:D