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Steam Powered Underwater Jet Engine
Bob Vila's Hammer writes "An Australian engineer, Alan Burns invented a very efficient underwater steam powered jet engine. "Steam that is produced from a petrol or gasoline fueled boiler emerges at high speed from a rearward-facing ring-shaped nozzle into a cone-shaped chamber. Shock waves created as the steam condenses are focused by the chamber to blast water out of the back. Besides powering watercraft pretty efficiently, it can also be used as an extremely robust pump. Pretty Cool."
The engine
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One thing I'm curious about is why they can only be scaled to 300 horsepower... Seems like if a 20 cm one can put out 30 HP, a big one could put out a lot more. It also might be fun to install a 20 cm one into a ketchup dispenser at McDonald's or something. And also, will it shoot potatos?
Todman shoved large quantities of lard and cardboard into the inlet without the pump suffering any ill effects.
COWBOYNEAL NOOOOOOOO!!!!!!
From where would you supply the air for the necessary bubbles? If you're in a submarine that's been submerged for say 2 weeks, is there a stable source of air to inject?
~A'Ëq'i4d)^'$ÊSÈòB
This is something that would really be great in areas where there are lots of scuba divers or manatees. I have seen the results of flesh being chewed up by prop blades. Not pretty.
I remember reading in a super-cavtation article about underwater engines like that - basically "underwater jet-engines" - I mean, of course it's not quite true, it operates on different principles, but the functionality is pretty similar.
;-)
btw, super cavtation is where you make the nose of your _insert_vessel_here_ blunt but it goes so fast that the vapor pressure drops until the vessel (usually a torpedo / bullet / whatever) would be in an airbubble (technically steam bubble! - though there are dissolved air that boils into the bubble too) that it creates itself (and maintains) and hence has no liquid drag for the rest of the vessel (as in, besides the blunt nose).
The engine I read about was actually reacting seawater directly with aluminum shavings and expelling hot steam (or something like that). I am pretty sure there were something else but I can't remember what it was (I don't think it was iron-rust, though, for all of you thinking of thermite). Anyway - neat stuff; should change underwater combat a whole lot.
should get myself one of those to go war(ship) driving
My life in the land of the rising sun.
Sounds to me like it's full of hot air.
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The water-jet engine was invented by a New Zealander some years ago. The difference with this thing is it uses compressed steam rather than the usual propellar
I'll let you figure this one out yourself....
Banaaaana!
Sure, me too...I prefer steamed flesh any day, over chopped-by-prop mammals, who doesnt't?
Bill Hamilton invented the jetboat back in the 1950s. It uses an impeller (not a propellor) to provide thrust.
Boats driven by jets are useful since they have better water clearance and can be used in shallow waters. Edmund Hillary (of Everest fame) took a fantastic boat trip up the Ganges river, as far up the headwaters as they could go, which turned out to be pretty far...
Such technology would be fantastically useful in the Florida Everglades for example, where conventional outboard motors wreak havoc with marine life, particularly the dugong.
If anyone ever gets to New Zealand on vacation, make sure to go on the Shotover Jet boats. They do a full 360 at high speed; can't do that with a conventional craft.
STF
thats where the supercavitating comes in.
"d'uh"
'There is a Light that never goes out.'
why electrolosys of course, just like in all the serious boats out there.
Imagine if the drive which produces steam is not desiel or petrol, but nuclear!
Enough "air" and steam for everybody.
Moreover, imagine if the sub doesn't use neutral bouyancy but flies through the water.
One thought though, if you're doing 90 knots underwater when the sea is full of debris, you might want really good maps and a kick ass gps+VR rig to guide you through the canyons, because I doubt sonar will be able to image for you fast enough.
From the article: With no moving internal parts, and no propeller, the engine should be cheap to manufacture.
I especially like the part about no moving parts... Moving parts are good to avoid in all cases, when possible... They wear and need replacement. Nice one!
.: Max Romantschuk
It is estimated that a gazillion fish die every day from cold. This new jet engine provides a wonderful means of transportation and enriches the lives of nearby sea food.
and in only 15 years we'll be seeing one power some sort of vehicle on Junkyard Wars / Scrapheap Challenge...
That could be scary. Imagine that thing in your hot tub.
Tim: Ahhhhh... This is great, all we need now is a bit more power. [Grunt] I'll just set it to 500 knots.
*click*
*foom*
Jill: Gargle gargle gargle
Tim: Jill? What are you doing? You know, going underwater in the hot tub isn't good for your ears. Are you listening?
I guess that's a bit off topic... Meh...
The bubbles are formed by steam.
"A language that doesn't affect the way you think about programming, is not worth knowing" - Alan Perlis
From more to less likely:
(1) Efficiency could peak at 300HP designs - it may be that any larger becomes horribly inefficient. Since it relies on squeezing compressed air and steam into an open tube, there might be a point at which there simply is to much room for the reaction to take place in given an incoming water velocity.
(2) The design may not be completed - possible design flaws may limit this versions' abilities to scale up.
(3) They may simply not know how big it can scale if their simulator isn't powerful enough to run a detailed simulation of a larger engine.
The design would require revamping most current hull designs to accomodate an intake for better waterflow to the motor. ...
Well, there are a lot of jet powered boats on the water right now. This is just a new way to create the pressure necessary to move the water and push the boat forwards. Guessing off the top of my head, I'd say that making a retrofit to existing jet-powered boats would not be a big problem at all.
Also, how big is the motor? It might be far too cumbersome to fit in anything less than a 20 foot boat. How much does it weigh?
Boilers can be pretty small - definitely no larger than the engines that currently take up space (and I'm referring to inboard motors as opposed to outboards). If you're referring to using a reservoir to hold the water to be boiled, why not just use the lake / river / whatever water to boil? True, salt water boils at a higher temperature, requiring more energy to create the steam, but I'm sure that if the boiler is powerful enough to creat the amount of steam it needs, it could handle that extra energy.
I bet you could also make an outboard version.
- "Nobody came out that night, not one was ever seen. But Old Man Stauf is waiting there, crazy sick and mean!"
Eagles soar, but wease^H^H^H^H^Hwhales don't get sucked into jet engines?
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Re-read the article, air is injected into the water intake before steam is added. The air bubbles in the water affect how the steam reacts with the water/air mixture and helps produce the shockwave critical for propulsion.
Well, I'm sure somone else has noted this : a nuclear energy source like on a warship would be perfect for supplying the steam. By venting the secondary steam from the boilers directly into the water like this you could easily get ten times the power with the same size engine (though you'd need more higher output reactors) I am sure an engine like this would be EXTREMELY noisy, so the warship would have a set of these steam jets it could fire up when it needs to move somewhere fast, and some quieter source when submarines are a worry. Imagine an aircraft carrier and a few destroyer escorts with flank speeds in excess of 70 knots (it would have to have hydrofoils as well, because otherwise the hull speed would be to limiting. Yes I'm aware it might be decades before a carrier this sexy is built, if ever). Sure it would be vulnerable to torpedoes, but the idea is it could be a MUCH more threatening weapon with this kind of speed. It could patrol a larger area, escape from danger, and have a certain intimidation factor when its located somewhere since it could arrive suddenly, launch a strike force, and depart before the enemy was aware.
As long as were speculating, imagine an even more effective weapon, a ship loaded full of missiles and rocket launched drone strike aircraft (so no human pilots risked. Yes I'm aware that such aircraft might be say, half as effective as human piloted planes but if they cost 1/4 as much to build its a MUCH more effective weapon. It could very well be cheaper to turn out somewhat dumb long range missiles and semi-reusable drones by the thousands, with no additional pilot training needed. The "pilots" would be a group of technicians behind consoles far from the battle, with embedded computing in the planes doing most of the flying, the human being just to pull the trigger. Without all the risks of training pilots and maintaining aircraft (the planes would be stored in sealed containers until needed, with a small set used for training) and the fact that these planes don't need nearly the quality control in manufacturing (if you lose 10% of them in a mission due to shoddy construction but they cost half as much or less to build its definitely worth the trade off) you'd have a better solution than at the present.
Why isn't this done already? Well, in the 1970s and earlier where most of the present airplanes were designed, communications technology and computers were not good enough or reliable enough. Today, most of the money is spent on operations and on a couple of new aircraft. Also, the current leadership is made up of pilots, who don't want to be replaced by scrawny pasty faced techs sitting at control stations. Finally, there's a current bandwidth problem : military communication satalleits don't have the capacity for the hundreds or thousands of video links needed.
The drive was invented by Australian engineer Alan Burns and developed in Britain by engineers at Pursuit Dynamics in Royston, Hertfordshire. Last week, New Scientist witnessed a version just 20 centimetres long develop around 30 horsepower (22 kilowatts) in a test tank, enough to power a speedboat. But the company says it can be scaled up to about 300 horsepower.
Which seems a little disappointing. I liked it better thinking of a contraction of "masticate" and "lacerate"
"Even if you are on the right track, you'll get run over if you just sit there" - Will Rogers
am wondering how you get this engine started?
:)
That's the exact same thing I was just wondering. The best way for me to find out is to go build one and try it! I'll be sure to make a website once I do it, and after that, I'll try to stand up to the litigation from Pursuit Dynamics
Seriously though, it looks like there's a small venturi at the exit of the steam chamber which would focus the steam backwards and start the process. Also, if you don't have steam pressure (any time the boiler is off overnight), the water will flow in the steam supply line. When you start it, the steam probably pushes the water out, generating a small current that builds as the engine starts working.
- "Nobody came out that night, not one was ever seen. But Old Man Stauf is waiting there, crazy sick and mean!"
It's a pity that the stall speed of most modern fighter aircraft is around 150 knots. Imagine how easy carrier landings would be if you and the carrier could head into the wind and the carrier would match speed with the fighter!
One question... What if they run into a school of tuna? ;-)
Kinda makes me think of the "Bass-O-Matic" commercial on Saturday Night Live...
I love the way technological evolution works:
Diesel Powered -> Nuclear Powered -> Wood-fired subs!
I don't know. It depends on how clever we are. The stealth bomber is jet propelled and yet the can hush it by mixing cold air with the hot exhaust and carefully shaping the jet so that you only hear it with sensative microphones when its directly overhead. Or so the govt said in 1991 on the news.
... jet engines vs. propellors did for 'planes, we got a winner. But if i remember rightly (no expert here, don't hurt me), the advantages to aircraft are higher power to weight ratio and lower maintanance costs. Only one of these (the latter) seems to be really relevant in the water :( Any thoughts?
BTW when checking this with google, look at the first link i got: http://www.dkgroup.dk/hydro2.html - the "Hydro Air Drive", yet another related idea.
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If the dolphins complain, then we can just give them complimentary underwater-jet-packs. Then, on romantic moonlit nights, passengers on cruise ships can watch the playful dolphins jump over the boat.
Why did this get modded up? While there are no facts listed, the company does describe the engine as "Very quiet" on their web site! Have you ever gone for a ride in a small boat of current design? I wouldn't exactly classify them as silent. In fact, it's more along the lines of too loud for even a shouted conversation of any useful length. Without any facts you're fears/claims are meaningless and alarmist. For all we know the lack of prop cavitation and direct transmission of engine vibration through the drive shaft to the water might in fact make this a quieter engine! No claims can be made without seeing, using and testing it ourselves, or reading reliable documentation on the subject.
This sounds amazing:
* Cheap to produce
* Incredibly robust (no moving parts)
* Efficient (although they don't give any numbers)
* Safe(r) for the environment
* Multiple uses (pumps)
* Scales well in a small package
Without seeing any numbers, it sounds like it beats the pants off of outboard engines. My 70HP Evinrude has been rebuilt twice because of sand-suckage, and standard jet impellers are too inneficient.
So what's the catch? I want to see some real numbers. If there's no catch, then I hope and think this thing will revolutionize the small-craft market.
I read it as 'steak-powered' :D
From the article:
:-)
"The steam drive can also function as an extremely robust pump. It can shift water, sewage or oil, and in a demonstration for New Scientist, Todman shoved large quantities of lard and cardboard into the inlet without the pump suffering any ill effects."
So the real question is when will someone make one big enough to become the first under water roller coaster?
Furthermore:
"It doesn't simply mix -- it macerates," says Todman".
Hmmm... macerates... "to soften and cause to disintegrate as a result"... oh well... just don't turn it up all the way
I was thinking more of the possibility for torpedo engines - if it's small, cheap, powerful, and fast (and sufficiently fuel-efficient, which the article didn't mention was good or bad about this) it may be more effective for making anti-ship weapons than faster ships.
Bill Stewart
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
Won't somebody PLEASE THINK of the ENVIRONMENT?!?
/second, raised approx 3 degrees.
Sigh. Let's look at some numbers, shall we?
Volume of water going through (arbitrary example) 20cm dia steam-powered jet engine at 10m/s: 3.14*.10*.10*10 = 314 litres
Volume of water in 1 square kilometre of 20m deep ocean at 20 degrees: 20 thousand million litres.
Time to traverse 1km in boat at 10m/s = 100 seconds = 31,400 litres of 4 degree warmer water.
Mix 31,400 litres of 4 degree warmer water with remaining 19999968600 litres.
OH DEAR GOD, NO! IT'S 0.00000628 DEGREES WARMER!WE'RE ALL GONNA DIE!!!!
So, if 1000 boats all simultaneously traversed the same 1km square section of water, the water temperature would be temporarily raised 0.0628 degrees.
Well, better discard this invention and go back to conventional petroleum powered motors, for surely they are the safest, most environmentally friendly way to proper water craft.
(This dose of reality brought to you today by the concept of common sense. Please try some.)
You are in a twisty maze of processor lines, all alike.
There is a lot of hype here.
That would make it a Self Contained Underwater Boogie Aparatus.
cat
I can't conceive how it will function as a primary power source because of the mechanics that would be necessary to start the process.
In the same manner, you won't have a "neutral" since it probably can't be turned off and on rapidly for docking maneuvers, et al. Perhaps it could use buckets like a jetski (or any jet aircraft using clamshell reversers), but I wonder how well it reacts to a high backpressure created by such a device....
Maybe we'll get to see some of that great KABOOM action when these things explode or when two boats collide!
One thought though, if you're doing 90 knots underwater when the sea is full of debris [slashdot.org], you might want really good maps and a kick ass gps+VR rig to guide you through the canyons, because I doubt sonar will be able to image for you fast enough.
The speed of sound in air is over five hundred miles and hour. I don't know what it is in air but if you assume that it is half again as fast in either direction, then it cannot be less than two-hundred and fifty miles per hour, nor more than seven-hundred and fifty miles per hour at the high end.
If things are workable at the low end, the high end is fine. Therefore, the low end is the 'danger zone.' Assuming an active sonar range of one mile. Now, submariners don't like using active sonar, it's analogous to a soldier standing in an empty field at night and shouting, 'shoot me!!'
Be that as it may, working with the assumption that the submariners use it, it is fairly safe to assume that any system they use for detecting objects in their path would be used to provide the most proactive solution to the problem of not running into things possible.
Basically, if you were doing 90 knots when you turned on your sonar system, in a place with potential hazards at close range, you might not like it, but assuming you spent all your time pinging like crazy, it is safe to assume that you would have advanced warning on objects in the distance because your sonar data would let you catalog them before they became a threat to you.
Note also that GPS systems use radio waves which don't work well at all when transmitted through water.
Be that as it may. It is of course true that VR-goggles and GPS techology are both very cool.
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Two points.
1. The speed of sound in water is actually faster than in the air (it is related to density).
2. Pay attention to the anticipated speed that they feel can be accomplished with the engine. 90 knots is faster than most torpedoes (ignoring the rocket propelled supercavitating ones). The users of this engine may not care too greatly about being noticed since they can outrun just about anything which could attack them.
You also couldn't reverse the thing the same way you reverse a normal vessel
But with an engine that small and no mechanical or electrical linkage needed to the actual engine - just turn the whole thing around.
You could use it like an outboard/sterndrive affair
On tug craft you could use several to replace the current bucket prob designs.
On large ships you could use banks of these along the hull. If they can orient them then you can spin the vessel in its own length, move it sideways, offset the forward and stern banks to assist the turning. Stopping would be easier as a big stern prop is horribly ineffecient in reverse, but turning the engine pods around would not effect them (Probably - not sure if reverseing the water flow over them may make them less effecient). Want to avoid a collision, just turn them sideways under way and shove yourself out of the way sideways.
The beaty IMHO is this thing is so simple all you need is a pipe and valve to regulate the steam from a central boiler, and a control system to turn it.
This could potential make for very agile vessels.
Engineers should be forced to study railroads, they were the high-tech of 150 years ago, and they actually invented many things, most especially modern telecommunication networking!!!!
I read that as steam powered underware, I was really disapointed when it turned out to be more boreing...
-You're wasting your time. Alfador only likes me.
... fuel, efficiency, fragility. Consider this:
... as in the Navy's big ships. And how does the efficiency of transferring steam's energy into liquid motion compare to that of a propellor?; and
1) Maintenacnce of Boiler - boilers are not trivial creatures. They run hot and need regular maintenance. And I want to see the boiler that runs on _salt_ water and doesn't have a _big_ maintenance budget (look up salt water evaporators);
2) Efficiency - boilers aren't great at converting the heat energy to steam unless they get quite fancy
3) No moving parts - is a red herring. The question is how fragile are your parts? Little holes get clogged up pretty quickly, not necessarily when running, but when the thing is stopped. And cardboard doesn't compare to what is really out there. What happens when a piece of plywood jams into the throat of the nozzle and blocks, or just restricts, water flow?
It's a neat idea but I think it's a solution looking for a problem.
"Consensus" in science is _always_ a political construct.