What about a piezoelectric motor sat on a car engine? To capture the wasted vibrational energy of the car.
You could then use the motor to power a little smiley face that lights up on the dashboard. It might quieten down the car a bit too.

Yup, I believe that’s currently being researched/applied but the energy available is fairly small and hard to get.

What about a piezoelectric motor sat on a car engine? To capture the wasted vibrational energy of the car.
You could then use the motor to power a little smiley face that lights up on the dashboard. It might quieten down the car a bit too.

MMM… sat in a traffic jam, ickle motor absorbing all that energy from vibration so the car can smile at you, by turns doubling, tripling, quadrupling your frustration – it’ll never catch on 🙂

Once you have an electric/petrol hybrid there are all sorts of opportunities for scavenging electrical energy besides braking.

My ideas are electromagnetic damping in the shocks, a steam turbine driven off the rad (Stirling engine is it?) and a generator attached to an exhaust turbine. That’s my fave idea, since we already make turbos nice and easily. Attach some magnets to the fan and bosh.

Mine is clevererer. A boiler that is kept boiling by electric elements that are powered by a steam turbine driven by the boiler.

I’m just thinking where to get an endless supply of water from and where magnets fit in to all this. But once I’ve worked out those details, my world-beating device is ready to go.

Do I win £5?

My ideas are electromagnetic damping in the shocks,

Exists, tiny amounts of energy are harvestable on a normal vehicle – heavy goods are pretty usable. Checkout genshock.

a steam turbine driven off the rad

Temp not great enough but, though potential with other fluids other than steam – its under investigation…

Stirling engine is it?

At that Thot, the efficiency would be sweet FA on stirling.

generator attached to an exhaust turbine.

Sort of under way, in a round about way – problem is slowing and cooling the exhaust increases losses in the engine, so you can really only scavenge off-throttle energy (which is small) and give it back on acceleration. But this is under investigation too. As is thermoelectric generation from exhaust and coolant.

If you want to see perpetual motion in action then I simply invite you all to come round my house and watch my mother in law’s jaw.

It’s been constantly moving since 1943 and doesn’t appear to have stopped once.

Temp not great enough

It could be. You know when you undo the radiator cap on a car.. all that hissing and boiling..? If you want the fluid hotter just slow down the pump or adjust the stat.

My idea was to have the turbine before the rad, then you’d need a second water pump after the rad to create the necessary pressure drop across the radiator and hence temperature drop, assisted by cold outside air. I’d have thought a 50-60 degree temperature drop would be achievable, based on no calculations. I read that a third of the energy in the fuel ends up in the coolant – there must be a way of harvesting that.

Re exhaust turbine.. yes, it would choke the engine.. a bit like say, having a butterfly valve in the throttle? The exhaust gasses are still expanding – it’s that expansion I am interesed in.

Actually – I am forced to admit that the best way of scavenging the waste heat has been invented by someone else already – the 6 stroke engine.

It could be. You know when you undo the radiator cap on a car.. all that hissing and boiling..? If you want the fluid hotter just slow down the pump or adjust the stat.

But you can’t run the engine hotter than that (manufacturers run it at the max possible as it’s most thermodynamically efficient) – but the steam generated at that temp and pressure is not sufficient to run a turbine. Turbines rely on dry steam, not saturated steam with water content. If you adjust the stat you build up air locks in the coolant system, which causes hotspots and overheating, unless you run at higher pressure. There’s a reason this isn’t considered a viable option, don’t think they’ve not thought it through!

My idea was to have the turbine before the rad, then you’d need a second water pump after the rad to create the necessary pressure drop across the radiator and hence temperature drop, assisted by cold outside air. I’d have thought a 50-60 degree temperature drop would be achievable, based on no calculations. I read that a third of the energy in the fuel ends up in the coolant – there must be a way of harvesting that.

You’re hoping to get a rankine cycle into the coolant system of a car. What you’ll find is you need to massivey increase your radiator size to condense fast enough and you would need a tough inefficint turbine to extract the minimal energy you managed to put into it. I’m actually working on a mini rankine cycle rig at the moment, want me to go through the calcs for it? You’re right, there’s stacks of heat goes into the coolant, it’s jsut not easily accessible as it’s low-grade heat. Several manufacturers have attempted thermoelectric radiators which return a few percent to the elec system. Works fine but really it’s not worth the additional cost and design. Who knows as fuel costs keep rising though.

Re exhaust turbine.. yes, it would choke the engine.. a bit like say, having a butterfly valve in the throttle? The exhaust gasses are still expanding – it’s that expansion I am interesed in.

Not the same. A bit like that, yes, but if you raise the exhaust pressure you’ll just end up reducing the cylinder fill but in a way that leaves a bulk of uncombustible gas. I’ve not thought it through in detail but effectively closing the exhaust is not the same process as throttling the intake and would have significant effects on the way it works. Seeing where you’re going though.

As for the 6 stroke, you don’t see many of those in the real world do you 😀

There’s lots of interesting research going on all over youtube about PM and free energy harvesting. For example:

http://www.youtube.com/watch?v=2cUS03yNl40

WTF is that video? Got to say that really doesn’t show anything like “free energy” or “cold electricity”. Entropy can’t be negative. Change in entropy can be negative.

As someone working in the field of energy harvesting I can assure the general public that researchers have covered most of the bases you can think of (or find on youtube) and many more, but we do occasionally find some interesting stuff that hasn’t been covered. However usually it’s never been investigated due to costs of implementation being higher than gains or because the technology to do it doesn’t exist. It is interesting reading around the internet though, sometimes it sparks a bit of a thought!

However, at the end of the day the idea of PM has been explored time and time again and every example of tech that proves it possible has fallen by the wayside as reality matches theory – it’s just not possible, but it will continue to intreague those who can’t see why it’s impossible.

As for the 6 stroke, you don’t see many of those in the real world do you

You know what I am talking about though? The four normal strokes then spray some water in, which evaporates giving another power stroke. It works really well apparently in principle – the guy built one from a single cylinder air cooled engine using diesel injectors, and it ran cool to the touch.

Re the exhaust turbine – I reckon there’s mileage in it. Perhaps if the turbine was further away from the exhaust valve where the exhaust manifold would form a sort of pressure accumulator.. so on the exhaust stroke the pressure builds, that exits through the turbine when the other strokes are going on but if you could arrange for the still spinning turbine to lower the pressure in the exhaust manifold by sucking a little more air out, the next exhaust stroke would be far less obstructed.. if you see what I am getting at. A bit of fluid engineering.

I’ve got a ton more of these ideas by the way 🙂

This machine is as nears as it comes to being one – and it confuses me completely
[video]http://www.youtube.com/watch?v=5CcgmpBGSCI&feature=player_embedded[/video]

http://www.fasterthanthewind.org/

I saw on some science program in the last week that the way in which the toast is buttered has been shown to knacker the buttressed down “law”. If the butter spreading is gentle then butter down/up is random. Vigorous buffering causes a shift towards a more dependable drop outcome, but I can’t remember which. Something to do with the shape of the toast being affected and aerodynamics. I suspect it needs to fall from a minimum H too to allow the forces to affect the outcome.

TJ, I still haven’t identified whether that prop is linked to the wheels or not!

The toast thing is of course rubbish. The only reason it lands butter side down is because of the speed it slides off the plate. It’s enough to impart enough angular momentum to the toast that it’ll do half a turn before it’s covered the typical plate to ground distance. Carry it butter side down and it’ll land butter side up. Try it – I did.

If I remember correctly, in that faster than the wind machine the wheels drive the prop, but the prop does not drive the wheels… just like a bike freewheel…

As for the exhaust turbine idea mol… I would imagine that the back-pressure created by the turbine would cause a loss in efficiency greater than any power that could be recovered. For instance, the design of the exhaust is such that they use the speed of the currently evacuating gasses from one cylinder to create a pressure drop at the exhaust valve of the next cylinder to help draw the gasses out. Any increase in pressure here will lead to less efficient emptying of the cylinder, and thus a lower efficiency. I understand what you are suggesting, but it is already essentially what happens, and sticking anything else in the way causes problems! This is what happened when catalytic converters came along…

I believe that engines using turbos actually suffer a little from this issue too, as the back pressure from the exhaust turbine causes less than complete evacuation of the cylinder, but they more than overcome this loss of power by cramming in more air/fuel mix into the cylinder.

coffeeking – it just makes my brain hurt.

I think they are just geared together – the wheels drive the prop which creates the thrust that why it can go faster than the wind – it still gathers energy from the wind

Or its magic

I reckon there’s a way to make it work 🙂 (the exhaust turbine thing that is) Now where’s my machine shop and welding gear? Anyone got an old car I can experiment on?

TJ.. yes they are attached, but only so the wheels drive the prop, all forward propulsion comes from the prop itself, not from the wheels.

mol… do you know anyone called BA, or maybe Hannibal or Murdoch… just get them together and lock them in a shed. I’m sure they’d come up with something!

I’m just getting started muhahahaha!

Edit: let me just think about this a bit more 🙂

Mike – if so then it couldn’t go faster than the wind – I don’t think there is a freewheel – at low speeds below wind speed the prop drives the wheels but at higher speeds the wheels drive the prop.

Funky nick – if that was so it wouldn’t start

there is an explanation on the link I think – but it just make my brainhurt

Below windspeed the wind just pushes it along like a kite. Once it’s rolling, the wheels drive the prop which generates thrust and accelerates it through the windspeed threshold. I assume the limiting factor is aerodynamic drag eventually. Or something in the transmission breaking 🙂

Mike_D – Member

Edit: let me just think about this a bit more

Brain hurting yet?

I think I understand it, but it certainly doesn’t lend itself to a concise explanation.

Or, to put it another way, yes 🙂

TJ – the DDFTTW car is nothing like perpetual motion – it extracts energy from the wind. I think we eventually got to an explanation in http://singletrackworld.com/forum/topic/weve-done-planes-on-elevators – though I can try and explain it if that doesn’t help.

TJ… why would it not start if the prop doesn’t drive the wheels?

And why would it start if it does?

aracer – I know its not really – it just seems like it

funkynick as I say it makes my brain hurt 🙂

If its thrust from the prop that is driven by the wheels that drives it then at rest there is no thrust as the wheels are not turning

If the prop is connected to the wheels solidly then at rest wind turns the prop which turns the wheels which starts it moving

Brain-hurty is good… just remember that! 😀

If there is no drive from the prop to the wheels, then the prop just acts like a sail to begin with. The wind pushes against the two ‘thin sails’, and this is the initial thrust needed to start the vehicle moving slowly. But as it starts moving the wheels start turning and this then starts the prop turning.

The idea being that this vehicle is supposed to be ‘sailing’, so all thrust should come from a ‘sail’. In this case it just so happens that the sails are rotating, but they still act as sails.

The harder one to grasp is that they plan to try using this vehicle to travel upwind at a faster speed than the opposite wind speed!!

Ok – with it being so streamlined it does not look like that would generate enough thrust.

If thats how it works tho thats fine.

Its still cheating. I think they have a conveyor belt hidden somewhere

The harder one to grasp is that they plan to try using this vehicle to travel upwind at a faster speed than the opposite wind speed!!

Given that it can travel 3x faster than the wind downwind, this seems entirely plausible. What I can’t work out is how it’ll get started. Downwind the wind just pushes it a bit until it reaches windspeed, but that’s clearly not going to work upwind. Or does it not have to propel itself from a standstill for it to count?

Most sail powered craft can sail upwind, although they need to exert a large force through their fins or keels to achieve it.

But whenever I look at wind farms I’m always worried that the effect of all those propellors will make the earth start to spin faster.

What I can’t work out is how it’ll get started. Downwind the wind just pushes it a bit until it reaches windspeed, but that’s clearly not going to work upwind.

IIRC going upwind it works the opposite way – ie the prop drives the wheels. Hence it starts from standstill in just the same way as when it’s running at speed. I’m fairly sure they run variable pitch props on these, so can set it up to extract lots of force when stationary.

Slinky spring down an up escalator.

Hmm, the turbine thingy in the exhaust….interesting…but how about using the pressure of the exhaust gasses to increase the flow of the incoming air into the engine combustion chambers, you could then effectively increase the swept volume of the engine meaning that you could use a smaller engine but get higher power output like you would from a bigger engine, sure you’ll have some lag between the turbine spinning up as the exhaust flow increases and the flow from the input turbine but just think of the possibilities.

Why has no-one thought of that befor…

er….oh, hang on…

Turbocharger? 😀

http://en.wikipedia.org/wiki/Steorn

http://en.wikipedia.org/wiki/Steorn

Why am I not surprised to see that their claim involves magnets?

Well, apparently it IS possible! You just need a superconducting loop to create a “time crystal”.
http://www.kurzweilai.net/forums/topic/death-defying-time-crystal-could-outlast-the-universe