By on March 19, 2011

We love staying ahead of the curve with new engine technologies like the Ecomotors OPOC engine, but without an engineering degree it can be hard to tell the the posers from the next big thing. So when something like the Wave Disc engine comes along, we throw ourselves upon the collective wisdom of our Best and rightest to help us make sense of it. In the video above, the Wave Disc engine’s creator, Michigan State’s Norbert Muller, explains his invention and its benefits including simplicity, light weight and efficiency. And, he claims, the technology is close enough to reality to have a Wave Disc-electric hybrid within three years. Hit the jump for more technical details, and be sure to let us know if this is worth watching or just another engineering dead-end.

New Scientist describes the Wave Disc’s operation:

As the rotor spins, the channels allow an air-fuel mixture to enter via central inlet ports. The mixture would escape through the outlet ports in the walls of the surrounding chamber, but by now the rotor has turned to a position where the channels are not pointing at the outlets.

The resulting sudden build-up of pressure in the chamber generates a shock wave that travels inwards, compressing the air-fuel mixture as it does so. Just before the wave reaches the central inlet ports, these too are shut off by the turning of the rotor.

The compressed mixture is then ignited. By this time the rotor’s channels are pointing towards the outlet ports again, releasing the hot exhaust. As the gas escapes at high speed, it pushes against the blade-like ridges inside the rotor, keeping it spinning and generating electricity.

In a hybrid application, however, Muller indicates that it would actually drive the wheels, and electrical power would assist in high-load circumstances.

In a PDF on the Wave Disc project, MSU describes the engine’s advantages:

MSU’s shock wave combustion generator is the size of a cooking pot and generates electricity very efficiently. This revolutionary generator replaces today’s 1,000 pounds of engine, transmission, cooling system, emissions, and fluids resulting in a lighter, more fuel-efficient electric vehicle. This technology provides 500-mile-plus driving range, is 30% lighter, and 30% less expensive than current, new plug-in hybrid vehicles. It overcomes the cost, weight, and driving range challenges of battery-powered electric vehicles.

The engine is also adaptable to multiple types of fuel, including hydrogen and natural gas. The government sees it as promising enough to fund research to the tune of $2.5m. But do you see this technology coming to the roads in just a few years? Given how many once-promising engine technologies have failed to live up to their promises, it’s by no means a foregone conclusion.

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35 Comments on “Ask The Best And Brightest: Wave Disc Engines?...”

  • avatar

    Setting aside any arguments for or against this particular technology, I would rephrase the question Ed asks in the last paragraph:
    How many radical new concepts in engine design have we seen each decade since the internal combustion engine first appeared?  Miracle engines that would make the reciprocating piston engine obsolete.  How many of them turned out to be viable?
    Wankel’s rotary engine is about the only one, and, whatever inherent advantages it may have, it has never exactly set the world on fire because its few advantages are more than offset by its more numerous disadvantages.
    In the meantime, engineers continue to improve and refine the reciprocating piston engine, boosting both power output and efficiency to levels unheard of just  five years ago.  I mean, I hope engineers never stop trying, but so far . . .

  • avatar

    Many, many years ago, when we still had turntables and LP records I remember the critics all telling us that Hall-effect direct-drive motors were an impossibility outside of a lab-controlled environment, because the magnetic effect could not be harnessed on a pancake motor. Well…. I happen to own one of those Technics turntables and it continues to work well without any maintenance to this very day.  IOW, I don’t put anything outside the realm of the possible.
    The advancement of the microprocessor has been  a boon not only to the PC world and the world of computing as a whole.  It has also infiltrated the auto industry. At this time in automotive history the internal combustion engine is at its zenith, but that does not mean that in the future we won’t be driving something a lot better. A ‘wave-disc engine” for lack of a better name may very well be part of that future, as could be more efficient electric motors powered by a more potent chemical-reaction power source, like a beryllium/uranium power source.

    • 0 avatar

      “at this time in automotive history the internal combustion engine is at its zenith”
      The “Wave Disc” engine is still an internal combustion engine.  It’s not too far removed from a Wankel rotary.

  • avatar

    I see a couple of common problems right off the bat. Number one on my list would be sealing and number two would be cooling. You have to have an effective seal for combustion or the shock wave as he calls it. A piston has rings what does this thing have? How are the parts lubricated or cooled? Neat concept but there is some physics to overcome. As it stands it doesn’t look viable without more information.

  • avatar

    It might work – once its re-designed by someone from U of M.

  • avatar

    That line that this is cutting edge research that private capital won’t touch due to risk seems odd. If the idea is sound and it can save x amount of gas and money, wouldn’t somebody invest in it? How much did GM blow on all the engines (rotary, V-6,5,4, etc, etc) they didn’t produce? How much did Chrysler spend on turbines, two strokes and gas electric powertrains?  How much has Mazda spent on the rotary in the past 45 years? Toyota on hybrids? Honda on hybrids? Briggs and Stratton on hybrids?

    • 0 avatar

      These days, private capital seems to only be interested in flipping:  something they can dress up and pass off to some sucker for a stupid increase in imaginary value.
      In contrast, this requires investment.

    • 0 avatar

      ^^ Sadly, this is all too true. Consider it another argument for financial reform. Why take risks on new ideas when the existing system allows profit without risk?
      It may comfort you slightly to know this is not the first time this has happened. In the heyday of the British Empire, all the smart money was in plantations in the Caribbean. Ideas like artificial dye had problems finding financial backing, to the point were lots of British ideas that would  eventually form whole industries found backing in Germany.

  • avatar
    M 1

    It’s a rotary diesel.
    He can have a vehicle ready within three years? Well, the video was uploaded in 2009, have they scheduled the unveiling yet?

  • avatar

    why does everyone compare this to internal combustion? this looks like internal combustion to me. You mean compare to piston IC?

  • avatar

    Not an engineer.
    But I see two problems right off:  He’s hustling the government for money; and his work is being praised by New Scientist, which seems to view science as a function of politics.

  • avatar

    Carquestions brought up three critical issues: sealing, cooling and lubrication. If it’s going to turn the drive wheels, it has to be flexible enough to handle variable loads at variable speeds. That’s not covered by the basic concept exposition, but those details can kill the concept in real-world use. Then there’s the input/outgo equation. How fuel-efficient is it, and what are the emission levels?
    Until the practical details are worked out and hardware developed and dropped into a vehicle, there’s nothing here but proof of concept. It would take huge amounts of time and money to move from POC to practical application, and only then could  the critical questions of durability, fuel consumption and emissions be answered. The wrong answers would make the investment worthless. That’s why venture capitalists are keeping their distance.

  • avatar

    Speaking of LP’s and turntables, i.e: record players, I still use mine and listen to LP’s and 45 rpm’s on occasion. Does anyone remember “flywheel power” over 40 years ago, heralded in Popular Mech. or Sci., can’t remember which? The theory was having a flywheel in a housing and spinning it to a great speed, the energy harnessed would allow a city bus to operate for a period of time before the wheel would have to be re-spun. That never made it to market, either. What of the Eco- or Evo- engine featured on here 6 months ago? Did that one die, too? It seems with all these technologies, they work in a lab, but once in the real world, and exposed to a load, poof! They don’t work, or are not practical.

    • 0 avatar

      Would you like your Popular Science flywheel from 40 or 30 years ago. I found both. I Love Google Books!
      August 1970:
      October 1980:

      EDIT:The 1970 issue is a good one! It features MITs turbine electric ’62 Impala, a propane electric Corvair and a bunch of other early experimental low-emission vehicles (Starting on PG 50)!

    • 0 avatar

      mazder3: Now you’ve done it! The article from 1970 is the exact article I read, right down to the crude drawings! That’s why I joined TTAC, as I know just enough to be dangerous! Thanks so much, that really made my evening!

    • 0 avatar

      Yup, I remember.
      About that time, PS was heralding the “Tri-Dyne” the “Slick New Rotary that could lick the Wankel.”  And that was the last the world ever heard about it.
      Or about flywheel power.
      It’s why I’m a skeptic; and why, when someone starts screaming “BREAKTHROUGH!” while asking for money, my hackles go up.  It used to be that sort of rot was hyped to sell Popular Mechanics and other john-readers.  Now it’s hyped to tap into some sort of public subsidy.

    • 0 avatar

      Just to let you know — Porsche is using something along those lines with their KERS system. This system uses the flywheel to store power then generate extra electricity when needed.
      You’re welcome. :)

    • 0 avatar

      The Swiss did use Gyrobuses as a alternative to electric buses after WW2. The Flywheel concept is interesting, but it has some interesting challenges. The flywheel in those buses mentioned had an external spinning speed of 900km/h, so to keep the noise level down, they were sealed in a pure hydrogen environment.

    • 0 avatar

      I’m not an engineer, but I believe the big drawback to flywheel tech is finding something to make the flywheel out of that can both store an enormous amount of kinetic energy yet hold together under the enormous centrifugal force. Carbon fiber materials hold some promise but it’s quite a challenge. Also, constructing a containment system for the flywheel in the event of system failure is a major issue (which is what freaks me out about Porsche’s KERS system, located next to the driver).

  • avatar

    When I first saw the title for this article the “wave disc” term had me thinking “this is yet another take on the dynacam engine” which, in spite of its on-paper promise and in-aircraft trials, languished for most of the 20th century before being bought out by European interests and subsequently mothballed.

    But having read the editorial it appears to be more similar to turbine designs. If so, the cooling and sealing solutions (if they exist in this case) would likely involve some of the same techniques utilized in turbines: forced-air cooling, labrinth seals and expensive alloys. It would also be interesting to see how this design solves the high BSFC figures that such designs are notorious for.

    The rotary, Dynacam and turbine engine designs do have one thing in common: they’re much more suitable for aircraft use than automotive applications.

  • avatar

    My thoughts on this (or any new engine technology) is simple. Build 100 of them, give them to independent testers for 100,000 miles and publish the results in an industry respected trade rag.

  • avatar

    Looks like a Diesel Wankel to me, and I’m not buying its viability.

    BTW, 25 kW is only 33.5 HP, so it will power either a very small vehicle directly, or a mostly-EV as a generator, and such a vehicle will require lots of battery.

    Naturally, a Michigan school scores the $2.5 million research grant.

    But look at this list of promises:
    “This technology provides 500-mile-plus driving range, is 30% lighter, and 30% less expensive than current, new plug-in hybrid vehicles. It overcomes the cost, weight, and driving range challenges of battery-powered electric vehicles.”

    At least several of those things cannot be true.  Even if you replace the ICE of a car with his tiny 33 HP motor, you’ve got to make up for it with something expen$ive and heavy.

    Let’s take up his 3-year challenge and see how he’s doing then.

  • avatar

    Well, the military is looking for something that is more efficient and eco-friendly. It could end up there first, after all the extensive and long testing they do, and help reduce fuel use and all the logistics expense and headaches that come with it.
    I believe Mazda said the Wankle can’t meet strict emissions requirements, probably because of the sealing issues. Maybe this thing can be scaled up to replace the thirsty turbines used in tanks where emissions aren’t as much of an issue?

  • avatar

    carquestions points out some valid engineering challenges that this design needs to overcome before they reach any form of viability.  I see a more fundamental physical problem here relating to compressible fluid mechanics and turbo machinery. For gases (or any fluid for that matter) to spin a rotor, the flow has to be attached to the surface of the rotor (or turbine blade). To be more accurate (and geeky), the boundary layer must stay attached to the windward side of the rotor to generate the necessary momentum flux. This is true for any compressible flow turbo machinery application from gas turbine jet engines to ordinary run of the mill compressors. Now, decades of research into shock waves have shown that they have a nasty habit of inducing boundary layer flow separation. Its a problem they first encountered while testing early supersonic jets. The flow separation would cause catastrophic loss of power and engine failures in the middle of flight in a phenomenon termed ‘unstarts’.  They eventually solved the problem by using advanced flow control techniques such as suction and vortex generators in the inlets of the jet engines. But the turbo machinery parts were always isolated from the shocks due to the difficulty of controlling shock wave induced boundary layer separation in those regions. This is true to this day.
    Now here, according the diagram provided, Dr, Muller envisages shock waves in the middle of the rotor assembly itself. I’m not sure if he has any method of controlling and preventing BL separation. The pdf provides no info on that front. So, until then, color me skeptical.
    For the geeks out there; an ungated version explaining the technical details of shock wave boundary interaction:

  • avatar

    Hmm.  Here’s a thermo geek not bothering to describe what cycle the engine obeys, nor what the specific fuel consumption is, nor why CO2 emissions from the engine should drop any more than you’d expect from stoichiometry.  I admit I found the man difficult to listen to, but i suspect he has invented a centrifugal turbine with combustion inside – k3w1, but in my view neither a reasonable use of materials nor a smart move given the up-thread comments about sealing and lubrication.  Those “shock waves” don’t look relevant to me ahead of the spark, which this device must have unless the compressor is a truly fearsome device.
    Color me very, very skeptical.

    (topgun, on review, well said!)

  • avatar

    All this reminds me of the guys that used to sell magnets to attach to the fuel line, to get the “correct polarity” of the tetraethyl lead, or some such rot.
    It all comes off as pseudoscientific babble – to wow an audience ignorant of engineering.  And yes, I’m one – but I understand some basic principles, and this thing makes no sense.  The skepticisms given by two previous posters make much more.
    My take, as I said, is that this guy’s found an elaborate way to ask for FREE MONEY.

    • 0 avatar

      JustPassin, a lot of things make no sense, until they make sense.  Way back when, the Wankel engine initially made no sense until NSU came out with the RO-80. While stationed in Germany with the military I briefly owned a USED RO-80, with a stick shift.  It was a dog, albeit a smooooooooth dog. It was slow on take off but once up to speed could smoothly cruise at 135 mph all day long. It seemed that it needed eight hours of maintenance or repair for every eight hours it was driven. It was in the shop more than it was on the road and smoked like a house afire (seals always going out) This wave-disc engine may very well work, but the Wankel works on the same principle on a larger scale, with twin rotors in many cases. It never caught on.

    • 0 avatar

      JustPassinThru: You know, you just reminded me of something. Back in the early-mid 1980’s – 1984, I believe, there was a guy who hawked platinum. This was a solution that you mounted under the hood and tied it in to either your fuel line or vacuum line, I can’t remember which, but the system was $50.00 and I bought one. When my mileage didn’t increase, I called the guy and he said to just send it back, as the car I used it on was my 1976 Dodge Dart Lite, 225 slant-six, 4 speed w/overdrive, and my particular car was already as efficient as it could be made, and actually did get good mileage. The platinum system was only meant for the big V8-powered hogs still on the road, at least that was what he told me. Apparently, there just isn’t any golden bullet that’s going to solve our fuel efficiency problem, although hybrids appear to be making a little headway.

  • avatar

    …because it didn’t work very well.
    In the Wankel’s case, the failure was of durability issues and inability to meet emissions requirements…and beneath that, poor thermal efficiency (the reason for the poor fuel economy; a greater amount of combustion energy was lost as heat).
    This thing may just, maybe, work.  But when someone tries to baffle me with bull-excrement, while failing to blind me with any semblance of brillance…I dismiss.
    This guy is going to have to prove it; and hopefully on his dime, not mine and yours.  If the thing can be shown to have merit; can be shown to meet the modern requirements for motor-vehicle use…someone’s going to be interested.
    But it’s his job to start proving.

  • avatar

    Hey, I’m Canadian, he’s not asking for my money, so best of luck to him, hope he gets the 2.5 million he’s asking for….
    By the way, it probably won’t work… he specifically said there’d be no radiators, so no cooling, which means the thing is going to seriously overheat and melt (or blow up… cause that’d be cool.) Anyway, best of luck to him, now back to the hockey highlights

  • avatar

    Here’s a compressor/expander that in principal could be set up as an engine

    I came across this in the 90’s and it looks like they are making progress in specialized applications – then, sealing and tribology were issues, plus the need for very precise machining.

    In the late 70’s, Union Carbide did some research on dual pistons in a cylinder (like OPOC) and that was meant to run without cooling. Or lubrication. Not a problem if you made it out of silicon carbide, except you needed strength and very close to net size casting – good luck machining that stuff.

  • avatar

    Ummm , where is the expandable volume of the chambers to allow the expanding burning gasses to apply mechanical force??

    • 0 avatar

      TTACGREG – my thoughts exactly. The only possible location for mechanical energy transfer is where the outlets line up with exhaust – where the number 4 is located in the diagram.

      Looks to me like they’ll soon realize that the best way to extract more energy out of the engine will be to add a bunch of “fins” or “blades” in another rotating layer, directing the exhaust backwards. Then a bunch of fins in a layer behind that, extracting even more energy. And maybe a layer or two out front to help compress the gas.

    • 0 avatar

      Heh, heh, Scott…

      Reminds me of a fellow with a similar last name, who had us all believing that we’d be flying to work @ 200mph by now. (Wankels were involved, too.)

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