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... you can have the fission engine BB, I want the fusion engine, in a Metro.
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Re the A4 Pacifics etc superb enigmatic thundering machines though an external combustion recopricating engine is never going to match the thermodynamic efficiency of an internal combustion engine so as far as steam is concerened it is turbines that are really exciting and efficient, whether it the pioneering Turbinia, the Mauretania, the SS United States or a modern powerstation.
Road transport is down to cost v benefit, if the kind of budget that applied to Eurofighter was used to develop say 1000 motorcars they would be something else though would cost 5 to 10 million quid a piece. The nearest to this happening has been the McLaren F1 and Buggatti Veyron though both were subject to budgetary constraints.
Also while gas turbines are superb in the are or the seas they have limitations in road transport, to me an ideal hybrid wouldn't have a box of Duracells and a punt 4 strke petrol engine, it would have an efficient refined CR diesel that is augmented by a gas turbine at high speeds, 60mpg and low CO2 in normal use and 150mph plus cruising.
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EDIT: "superb in the air or the seas they have limitations in road transport, to me an ideal hybrid wouldn't have a box of Duracells and a puny 4 stroke petrol engine ........."
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actually im in the process of inventing a vehicle that runs entirely on solar flares, but my development is being hampered because of a problem with the flux capacitor
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i think i damaged it getting it "out of the box"
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Modern diesel with additional exhaust turbo driving, say, an alternator for all electrics. Followed by a Stirling engine with auxiliary heat input from the engine cooling system.
It'd weigh a ton, and there'd be no room for passengers.
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Turning heat into energy... Imagine a car engine with the exhaust running through a heat exchanger a fully insulated engine exterior. All of this heat being stored in a matrix of special material.. How could that be used to provide energy on or off board the car?
BMW are already thinking along those lines with the 'Turbosteamer'. Steam generated from exhaust heat drives an expansion unit connected to the crankshaft, recovers 80% of the wasted energy from the heat of exhaust gases; improves fuel economy by 15%, *or* gives an additional 14bhp from a 1.8 litre engine. Also uses heat from the cooling system. The system has been designed to retrofit into the current model range.
www.gizmag.co.uk/go/4936/
www.steamcar.net/bmw-2.html
These articles are dated 2005; states volume production could be possible by 2015.
One question: do you lose half of your boot space to a big water tank?
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Cars have become so complex that the increasing efficiency of engines is countered to some extent by increasing weight. I agree that complex drivetrains are probably not the answer.
If these devices to use waste heat can be made simple and light enough, they do no harm. But really what needs doing is to strip away all the 'safety' legislation that has made cars heavier and more expensive.
Modern small turbodiesels are becoming very efficient and can probably be made even more so if buyers will sacrifice a bit of refinement. Lighter, less elaborate cars will enable the best use to be made of that efficiency for the primary purpose of cars: moving what Vietnam helicopter pilots used to call 'ass and trash', in other words people and goods. Lightweight cars don't have to be undesirable or boring. Indeed the weight constraint should act as a stimulus to radical design.
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saab got a innovation where the engine heats up the water in the tank kind of preheated water
this goes into the engine and faster warm up timesthere were other developments like the orbital engine, the stirling is the most fuel effiecent but no one knows why is it so
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The other problem with the Stirling cycle engine is that it runs at fixed speeds, so would have to be mated to CVT...
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We are talking about external combustion engines.
The Stirling engine while it can be efficient, produces very little torque. I guess partly because the pressures in the cylinders are low. I remember my Dad building a Stirling engine for the local college and the flywheel had to be spun by hand to overcome the static friction and get it going.
Think the Reverend Stirling used his to crank the rotisserie IIRC.
--
I wasna fu but just had plenty.
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These Revetec engines are claimed to give increased power and torque but are "significantly more fuel-efficient" than a conventional engine. It does away with a crankshaft and uses "trilobe cams" instead.
I wonder how much more fuel efficient they mean, and whether it will be reliable with the increased complexity?
www.revetec.com/?q=taxonomy/term/20
If you look at the photos on the right hand side of the page, looks like they are installing it into an old Opel Kadett or something..
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>>trilobe cams
Sounds almost Wankel like. (I expect DD'l really rap my knuckles for that!)
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SFAIK a lot of energy must be wasted in getting lumps of metal going very fast in one direction, stopping then and getting them going very fast in the other direction and so on, pistons for example.
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SFAIK a lot of energy must be wasted in getting lumps of metal going very fast in one direction stopping then and getting them going very fast in the other direction and so on pistons for example.
reciprecation?
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No - reciprocation, but I agree it is shorter and I think it is wasteful!
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>>I think it is wasteful!
No, not really. If, just for the purposes of a quick explanation, we can ignore the effect of the con-rod angle;
During 0-90 degrees after top dead centre, the crank needs to accelerate the piston downwards. Because the piston is pulled downwards and it's velocity is downwards, these multiply together to give a positive power. The piston takes power from the crank.
During 90 - 180 degrees, the crank needs to slow the piston - or in other words, the piston *drives* the crank. As the force decelerating the piston is now upwards, while the piston velocity is still downwards, these multiply to give a negative power. The piston gives power back to the crank.
180 - 270 is just like 0 - 90, but replace downwards by upwards.
270-360 is just like 90-180, but, again swap directions.
Over a complete cycle, it takes *no* power to move the pistons. The kinetic energy they take from the crank in some prts of the cycle, they give back later on.
Friction is the real enemy, this takes power from the system, and doesn't give it back.
Number_Cruncher
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the fly wheel is basicaly 19th century steam power technology, and stored energy from a piston in reciprication, why doesnt the wankle engine get more developement?
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Wankel = problems with the rotor tip seals, in the early days and, when NSU built them, lots of engines replaced under warranty. Now that Mazda make them the reliability is better but the fuel consumption is still not good.
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Minature Deltics please. All those nice quill shafts.
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>>why doesnt the wankle engine get more developement?
To my mind it is because there isn't a great advantage there to be had, and there are the disadvatages as mentioned by AS. It's a bit like the tri-lobed cam engine linked above; although there are deficiencies in the slider crank mechanism, it does have a certain simplicity in its favour.
Perhaps the time is right to turn our backs on the nasty, noisy, intermittent nature of reciprocating engines, and develop a continuous process more like that of a gas turbine. Perhaps in the form of an electric vehicle which could be given a boost by a gas turbine running on its design condition driving a generator.
Number_Cruncher
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Perhaps a nationwide system of smooth pneumatic tubes, like the messaging system they used to have in department stores in the forties and fifties.
Capsules always departed smoothly with a nice hiss, but arrived violently with an enormous bang that could reduce sensitive children standing nearby to tears.
Even with four-point harnesses, and perhaps since it's the 21st century airbags, these violent arrivals might deter people from travelling. And that would be good, wouldn't it? Or so many say.
Just an earnest suggestion.
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I'm thinking Diesel / Electric / Steam hybrid.
Hybrid electric drive similar to Toyota Prius with regenerative braking.
Diesel engine driving generator to supply additional power
Turbosteamer device like BMW's one using exhaust heat to generate more electricity to help drive car when cruising at speed.
I'd thought of this before reading this post, though in relation to rail locos rather than cars.
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In fact in the anorak far extremities of the net I stumbled across a group that designs modern 'virtual' steam locos, carrying forward the design and technology process from when it ended in the real world in the late 1950's / early 1960's.
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