The whispering wheel [Dutch invention can make vehicles 50 percent more efficient]

Radio Netherlands ^ | 15 december 2003 | by Thijs Westerbeek,

[aculeus]

A new Dutch invention can make cars, busses and other vehicles no less than 50 percent more efficient and thus more environmentally friendly. Better still, the technology is already available; it all comes down to a smart combination of existing systems.

This winter, in the city of Apeldoorn, a city bus will be used to prove that the claims about the new invention are true. These are quite bold. E-traction, the company that developed the bus, boasts fuel savings of up to 60 per cent, with emissions down to only a fraction of the soot and carbon dioxide an ordinary bus would blow out of its tailpipe.

In addition, the test bus requires no adaptation, its drivers need no extra training and there'll be no discomfort for passengers. It will simply run on diesel, just like all the other buses, and it should be just as reliable. One thing however will be very different; the Apeldoorn bus hardly makes a sound, hence its nickname "the whisperer".

In-wheel engine

All this is made possible by an ‘in-wheel' electric engine, in fact nothing more than a normal electric engine turned inside out.

The outer wall of a traditional electric engine is a cylinder lined on the inside with copper wire. If electricity is fed into the copper wire, the current will circle the cylinder on the inside at high speed. Cylinder and wire together are called the ‘stator' (because it doesn't move).

To change the electricity running along the inner wall of the cylinder into movement, another part of the engine comes into play: ‘the rotor'. This is in fact an axle, mounted in the centre of the cylinder, with permanent magnets attached to it. The electrical current in the stator pulls the rotor magnets along and the axle starts to turn.

The wheel works precisely the other way around. The fixed part of the engine - the stator - is now on the inside. The wire is wrapped around it.

The moving part of the engine – the rotor - is no longer an axle fitted with magnets but a ring running on the outside of the stator.

The magnets are fixed on the inside of this ring. If power is fed into the engine the magnets will – as before - follow the current, but now it's the ring on the outside, which will turn.

Eureka

And that's what makes ‘the whisperer´revolutionary; a ring functioning as a wheel. By just putting a tire on it you can drive a bus, a car, anything with it. Since the wheel is in fact the engine, no axles or any other friction-producing and therefore energy-wasting mechanical parts are needed.

Even the transmission is unnecessary; if you want to go faster you just run more electricity through the engine. And it works really well while braking, when the in-wheel engine works as a generator, produces electricity to charge the batteries.

Pack of Batteries

The power to drive the Apeldoorn bus is stored in a big battery pack that sits in a steel drawer under the bus. Changing the batteries every time they're drained would be impractical, as would be taking the bus out of service for recharging them for hours on end. Instead, a small diesel-powered generator built into what used to be the bus's engine bay continuously charges the whole battery pack.

Since in-wheel engines are so highly efficient, the generator's diesel engine can be very small, about the size of the compact city car's engine. Because charging the batteries is all it needs to do, the tiny engine consumes very little fuel and can run continuously at a speed of 1700 revs per minute, the most efficient rev count.

Clean and quiet

Passengers will find it more important that the bus is quiet and clean. No more roaring buses pulling away from the station in a cloud of diesel fumes. When the whisperer pulls away (and whenever it drives for that matter), the power comes from the batteries, not the diesel engine which simply keeps on purring quietly.

Furthermore, the constant rev count makes the catalyser much more effective, and the small size of the engine makes it possible to completely fill the rest of the engine bay with sound proofing. Being 90 percent quieter than other buses, the ‘whisperer' really deserves its name.

Testing period

In the coming six months the bus has to prove itself in everyday practice. Come summer, the city of Apeldoorn is set to decide whether to use whisperers on a larger scale in public transport. Dr Arjan Heinen, inventor of the whisperer and director of E-traction, radiates confidence: "This is a practical solution for present-day public transport. Every bus driver can get behind the wheel and do his job as before, only now it's quiet, clean and energy-efficient."

The future of the in-wheel electric engine seems bright. At the recent Tokyo Motor Show, it was the engine of choice in many of the futuristic hydrogen-powered concept cars.

© 2003

[Capitalist Eric]

Then why did we use motor manuels in the 60 70 to fix our engines?

Poor English skills, and a lack of technical knowledge to understand the difference between an engine and a motor...

[Capitalist Eric]

Unless it's a solid fuel rocket -- which is called a rocket motor.

This is true- to people who aren't engineers, and don't understand the difference.

[Poincare]

I was concerned with the added mass to the drive wheels which is the so-called unsprung wieght.

Yup. It makes more sense to have the weight of the motors inboard. But on a bus it doesn't matter so much I guess as long as the streets are relatively smooth.

[null and void]

Yup. A former co-worker of mine used to stand one on end on the side of a filing cabinet. He called it an engineer trap. Caught a lot of us.

I acquired one from him when I left. My new co-workers stuck it to the inside of the side of my metal desk, it had enough field strength to hold a stapler to the outside of the desk. It looks a little odd to see a stapler stuck to the side of a desk...

[Doctor Stochastic]

You're correct, water doesn't contain iso-octane (2-2-4 trimethylpentane) but it acts similarly in that the water scavanges the free radicals that cause premature detonation. So does tetrethyl lead and iron carbonyl (ugh, European usage) and tri-cresyl phosphate. Water adds no power in iteslf (it's already burned.) Water does allow higher compression.

I'm using "octane" to mean anti-knock properties rather than the percent iso-octane in the mixture.

Technical note: originally, the "octane rating" of a gasoline was the percent iso-octane in a mixture of iso-octane and n-heptane that knocked the same amount (measured by an engine with a knock-meter) as the test gasoline. With better anti-knock compounds, and "octane rating" of over 100 is possible. The definition has been changed over the years. (There's also the instant measurement and the average measurement, just to keep things complicated.)

[CommandoFrank]

Bingo... the diesel is famous for high torgue at low RPM. Low RPM equals long engine life...

I love my Ram Diesel...

[Dan Evans]

This is true- to people who aren't engineers, and don't understand the difference.

No, that's what rocket engineers call them, motors:

ABSTRACT:

The Space Shuttle solid rocket motor case assembly joints are sealed using conventional O-ring seals. The 5500+°F combustion gases are kept a safe distance away from the seals by thick layers of insulation. Special joint-fill compounds are used to fill the joints in the insulationto prevent a direct flowpath to the seals. On a number of occasions, NASA has observed in several of the rocket nozzle assembly...

[Dan Evans]

I love my Ram Diesel...

Maybe you can answer this question. Why do people who own diesel powered vehicles leave them idling when they are parked? Do you love that obnoxious sound or is it the nauseating stink?

[Museum Twenty]

bump for later

[expatpat]

Thanks. I guess I was right about the lack of novelty, but wrong about the rpm.

[Final Authority]

Water has been used to improve the performance of high compression engines at least since WWII. Water as a value of latent heat of evaporation which is quite high. This means that in order to cause it to vaporize it requires a lot of energy which in the engine takes heat out of the combustion or allows a slight increase in fuel use given the same temperatures and pressures. Since water slightly cools the intake charge before combustion it allows a slightly more dense charge of fuel with respect to air because the air volume is slightly displaced by the water and since the volumetric efficiency of the engine is finite over a certain range of operation the net air amount is decreased. This causes a slightly richer mixture because a carburetor doesn't know the difference between air or water vapor. A richer mixture often prevents knocking. When an engine doesn't knock it is using the available fuel most efficiently and this is where I suspect you gained fuel efficiency. To maximize the benifits of water injection one should consider turbocharging where water injection is syncronized with increase in manifold pressure and fuel delivery. This is where high performance gains can be realized, like in WWII air craft, but not for the purposes of increasing fuel mileage. Racing cars that use methanol use it because they can increase compression up to 15:1 and cool the charge as well but unlike water, alcohol is a fuel and provides the heat needed for power generation and alcohol evaporates readily at lower temperatures than both water and gasoline.

The whispering wheel is interesting because when I was a child I was interested in hybrid cars described much like the bus is now. This was over 30 years ago. The problem then is as now but not as severe. How does one control power to the motors without wasteing energy (heat)? Before power FET's it was difficult but even today it is not without energy loss. The article describes the bus not having bearings on the axles. It has to in order to roll even if the bearings are in the hub it will have a bearing surface somewhere. PM's have been the dream of high mileage cars for years but are limited in being able to allow high power density in an electric motor. It would be interesting to see one of these busses, loaded with passengers make it up one of the hills in the cities in Northeastern USA.

[-YYZ-]

Also efficiency. Typically, losses to friction increase with engine speed. Also partly because diesels just cannot rev high reliably - the high compression ratios and combustion pressures require very heavy pistons, con-rods and so on, limiting the maximum rpms.

The most efficient internal-combustion engines in the world are very large (hundreds of litres per cylinder), very slow turning (60 rpm?) marine 2-stroke diesels. These engines consume less fuel per unit of power output than any others. I think I've read the very best are somewhere around 50% efficiency, whereas you car's gasoline IC engine is doing about 25% at best.

I can't find the original link to the info on this engine, but check this puppy out:

http://www.k4viz.com/12-Cylinder.html

[KC Burke]

While the issues of torque from a standing start, unsprung weight and cost of the vehicle's engine and batteries give me pause, I do know that magnet material technology has revolutionized that field, albeit with cost problems as well.

The thing that gives me pause is the battery recycling. I built a facility for that some years ago and I will tell you that this is one of the most corrosive processes you can imagine. Some of the actual buildings, adjacent to the process areas, structurally corroaded to the point of replacement within ten years. Even rainwater falling withing the facility became so polluted a treatment plant had to be built to process it.

[Woodman]

I had this idea a long time ago, but I wanted to build it with superconducting electric motors in the in the wheel. I guess I will have to come up with another one now. BTW, the reason I never acted on this is because I didn't think it was a particularly original idea. I would love to seee if they even got a patent out of this application.

[avg_freeper]

new Dutch invention can make cars, busses and other vehicles no less than 50 percent more efficient and thus more environmentally friendly.

Efficiency is not synonymous with environmentally friendly.

Regardless of what "environmentally friendly" means.

(how exactly do you get friendly or cordial with an abstract idea like "environment"? Is it possible to be unfriendly with the environment. While strolling along the path the environment said, "Oh avg_freeper you never call. Aren't you my friend anymore? sniff sniff")

If you define "environmentally friendly" as reducing pollutants then you must lose some efficiency. My car would be much more efficient if I were allowed to rip all the pollution control doohickeys out of it.

[IncPen]

science ping

[CommandoFrank]

I can and will gladly answer your question:

Why do people who own diesel powered vehicles leave them idling when they are parked? Do you love that obnoxious sound or is it the nauseating stink?

Those who idle their diesel to warm it up are actually ruining their engine. The only time they should idle is if they just completed hauling a heavy load and the engine needs to cool down. And it doesn't take a long time to cool down to the normal temp range. I too see these people and shake my head in amazement. No load, no idling.

The days of the overly loud diesel are gone. Dodge, Chevy and Ford now produce very quiet diesel engines. I might add to some the sound of a loud diesel is the same as the sound of a Harley to it's owner.

That nauseating stink is the sound of pollution free air. Did you know that diesel exhaust is more pollution free than that of the internal combustion engine. Out of the four major polluants from internal combustion engines, diesels beat the gasoline engine hands down on three of the four polluants. Unfortunately, the one major polluant is the smell. When the diesels start burning cooking oils, and they will, they'll smell like french freedom fries.

[Dan Evans]

Thanks for the reply but I still don't understand why they do it. Does a diesel lose that much power when it's cold?

Reason I asked; I have a neighbor in my apartment complex who likes to start his diesel truck about six in the morning. He lets it idle while he goes back in to shower and shave. In the summer, all the rest of us have to get up and shut our windows so we don't gag. I can see where you might need a diesel if you need to haul big loads a lot, but it seems to me that whatever benefits one gets from owning a one would be far outweighed by the disadvantages.

And the guy that told you diesels have cleaner exhaust -- he's smoking grass. That's just silly. The diesel stink comes from oxides of nitrogen and sulfur. Inhale that and you've got lung full of nitric and sulfurous acid. And there isn't enough used french-fry grease in the whole world to fuel but a tiny fraction of diesel vehicles.

[vpintheak]

Says you!

[CommandoFrank]

-It's not that it loses power when it's cold. If you idle a cold diesel engine you varnish the cylinder walls. Tell your neighbor to read his owners manual and it should tell him not to do it. Even the new gasoline powered cars now say the same thing in the owners manual so I'm told.

A "guy" didn't tell me about the content of diesel fumes. I read a lab report on the makeup of pollution from gas engines versus diesel fumes. I'll try to relocate it and forward it to you. It was 2 or 3 months ago I read it.

Incidently, there are already diesel powered vehicles on the road running on used cooking oil, etc.

The benefits of a diesel engine versus gas in my opinion far outweigh the 'odor' factor. Much longer engine life, very high engine torque, and fuel economy are why I have one. And oh yea, I full time in an RV so I'm usually pulling a heavy load. Doing that with a gasoline engine is rediculous.