Dr. Norbert Mueller, an associate professor at Michigan State University’s (MSU) college of engineering, plans to have a new engine generating power through a 25-kilowatt battery out later this year.  The new engine connected to a generator and buffered by a battery and likely some capacitor storage would be powerful enough to run a full size vehicle.

The new engine is a “disk wave” chamber instead of a piston in a cylinder.  The disk wave principle uses a novel internal system to generate shock waves by igniting a compressed air and fuel mixture that propels rotors.  No valve gear, pistons, connecting rods or crankshaft.

Disk Wave Engine Layout. See Text below for the explanation. Click image for the largest view. Image Credit: Michigan State University.

ARPA-E, the Advanced Research Projects Agency-Energy provided a $2.5 million ARPA-E grant in 2009 to Mueller who says, “The wave disk engine is smaller, lighter and easier to manufacture. You have to be aggressive with your research in today’s world if you want to get anywhere.”

Mueller’s engine designed is said to reduce the weight of the engine by 30%, cut the weight of vehicle by up to 20%, improve the fuel economy by using 60% of the fuel for propulsion, reduce the total cost by up to 30%, and reduce the CO2 emissions by 90%.  That’s a very big list with big numbers all in the shadow of the American car companies’ headquarters in Detroit.

Mueller says they have four working bench prototypes, “We have engines – real, working, good-sized models – running right now.”  The MSU research team will turn one of them into a 25-kilowatt disk wave engine and generator package this year, “We’ll be able to drive a full-sized hybrid vehicle, or even a hybrid SUV.”

The engine is a system of rotors with radial channels that work due to timing as the shock waves are generated and move through the system.  To grasp what’s going on, consider a turbine with air going in one end and exhaust gas exiting the other, like a set of fans.  The wave engine – it seems – is like a squirrel cage or centrifugal fan with the air coming in the center and exhaust leaving the perimeter. Seems simple . . .  vent the incoming air fuel mix properly, ignite it and vent it out at the right moment.

Mueller said, “The engine was obviously hard to design. But it’s easy to manufacture. There are many parties – national and international – now interested in it, both in the automotive and base power sectors. Interest in the engine, that’s not a problem.”

The wave disk engine offers a major improvement using 60% of the fuel to create power, making it up to four times as efficient as today piston engines.  That offers a whole new calculation on fuel use.  It would also stuff a plug into the progress of grid charged electric vehicles.  Consumers and the oil companies will love this – cutting 75% of the gas bill for one and staying in the game for the other is a natural symbiosis.

In case you’re wondering why the piston engine isn’t ever going to catch up to turbine types, it’s the working function problems.  Pistons (plus the pins and a part of the mass of the connecting rod) have to go up and down essentially stopping and starting with the acceleration and deceleration twice with each crankshaft turn.  Lots of energy gets used doing that.  Plus there is the air turbulence inside the crankcase – twice the displacement of the engine gets pumped in every revolution using more energy.  There are also all those moving parts, compressing springs and other things gong on.  It’s astonishing the modern internal combustion engine is as efficient as it is.

Mueller can hold the bench prototype engine in just one hand.  The engines would be relatively easy to manufacture and reduce the overall weight of a car by hundreds of pounds, enabling hybrid vehicles to be perhaps 20 percent lighter and 30 percent less expensive.  A series hybrid could be very desirable, indeed.


50 Comments so far

  1. Chris on August 20, 2012 6:06 AM

    In the article you use both Disk Wave and Wave Disk. Wave Disk is the correct name.

  2. Matt Musson on August 20, 2012 8:00 AM

    What about stationary engines? If it is already working through a generator – could it be used for back up power generation?

  3. joe on August 20, 2012 1:17 PM

    I hope they explore marine applications because boaters really need relief from high fuel prices, heavy outboards causing weight distribution issues and the failure of pure electrics to provide anything close to sufficient range. Very exciting development!

  4. Jim Takchess on August 20, 2012 7:46 PM

    I feel this is the most exciting Arpa-e project. MSU, Let’s get one built!

  5. Roy on August 21, 2012 10:11 AM

    That efficiency rivals today’s CCGT power plants. And it appears to be much simpler, which could reduce the capital costs for power generation. It also appers to be able to be made small enough to tap off your homes natural gas line and supply all the energy you need at a very reasonable cost. Costco anyone?

  6. Paul Northfield on August 22, 2012 9:11 AM

    A very exciting development that could be adopted easily in many areas of energy generation!
    It seems to me that we could soon be seeing the kind of modularity in car powertrain design that we see in the computer industry. As each new advance arrives we can update our car with standardized replacements like adding a hard drive to a computer. If battery packs were standardized in size and termination and generators likewise the ability to upgrade to new tech improvements would create a whole new category of replacement and recycling. Older parts recycled for less critical uses as newer lighter and more powerful versions become available. Even if it were impractical for the individual, recycling the old one dropping in a new powerplant into a 3 year old Chevy Volt type hybrid may one day be cost effective as an upgrade and help reduce the resistance to adopting cutting edge tech that quickly becomes obsolete. I always thought the fear of cost of EV battery replacement was overstated and certainly only a problem for the next five or ten years until the tech has matured somewhat. The idea of paying rent for some parts like batteries and generators that could be replaced easily in a car could also become a viable business model.
    I would be very interested if there is any discussion of this online as I can see us reaching a point of massive change and disruption very soon. Considering the changes we have seen in computing and mobile I could see a similar exponential growth in energy tech driven by electric powertrains and storage

  7. George Francis on September 19, 2012 9:48 AM

    What type of horsepower and torque does this Disk wave engine produce? Is it easy to control the throttle?

  8. Fred A. Cerra on September 19, 2012 10:43 AM

    All that is needed now is Hydrogen as the fuel!!!

  9. Dan on September 19, 2012 10:45 AM

    If they reduce fuel consumption by 40% and CO2 emissions by 90%, what is the difference of the burnt fuel coming out as? CO? Looks like impressive numbers but the math (chemistry) doesn’t add up here…

  10. William Hegyessy on September 19, 2012 10:49 AM

    I’l love for this idea to work, but weren’t you at this stage 18 months ago? It looks like the equivelent of a 2-stoke mc engine. Have you concidered an extra compressor/and or turbine stage? You’ve piqued my interest to make a copy or a model engine. If this works good, let’s go flying!!!!!!!!!!!!!!!!!!

  11. Saulo Quevedo on September 19, 2012 11:28 AM


    If we use this new type of motor fuel (or even a small electric motor) to generate compressed air (Small, less energy for smaller mass involved) and reuse the compressed air to drive a motor of this type also (Big higher power) but for use with compressed air produced by the smaller engine, I think the result will be fantastic and economy.
    Think about it.

    Saulo Quevedo.

    InovaStar Projects and Technology Solutions.

  12. Col on September 19, 2012 5:33 PM

    What killed the wankel engine of the sixties was the seal wear and leakage problem.
    Is this yet another concept engine in the same boat ?

  13. Graeme Thomson on September 20, 2012 3:40 AM

    In 1963 my aviation engine instructor at Qantas designed this same engine as an inprovement on aircraft radial engines what he called a rota vane engine and the only stopping point at that time was with the seal and possible leakage problems his thoughts then were to use large piston rings for sealing. A proto type may not have been built if he was alive today he would be 90 plus years old. Thomo

  14. Enda on September 20, 2012 5:05 AM

    As per Cols comment. Rotary engines are not new. The wankel engine as used by NSU and latterly mazda. These engines are very efficient at optimal load but at part load are not hence why the efficiencies where not great. The hybdrid application will allow the battery to handle load fluctuations while the engine spins at optimal condtions. Audi showcased an A1 range extender last year with a wankel engine but the limiting factor in all this is the life of the seals to maintain compression. if he has cracked this then this will be brilliant

  15. kirit mewada on September 20, 2012 9:21 AM

    It’s will be a great achievement but after come in force in market with low cost,so any body can use this engine.

  16. kirit mewada on September 20, 2012 9:22 AM

    great invention.

  17. DW on September 25, 2012 8:24 AM

    As with all past rotary designs seals are a big issue. not only does seal wear affect efficiency it also has a big affect emissions.
    I would also like to know what the fuel composition is. 100% unleaded gasoline or does it contain some other component like alcohol and if so at what percentage since this will change the composition of the exhaust.

  18. Mike Kraynak on September 25, 2012 9:15 AM

    Is exhaust hot enough to heat my home while producing electricity?

  19. Marc de Piolenc on September 25, 2012 9:23 AM

    Sorry – not physically possible to get 60% efficiency in a simple cycle engine as they claim. Also, there does not appear to be any arrangement for compressing the incoming charge, so power density will be low enough to put this in the toy category. None of these numbers is credible. Gasoline pills, anyone?

  20. Steven on September 25, 2012 10:08 AM

    This is an extremely viable technology. If it can be used with Natural Gas, I see a massive benefit that would place us on the Energy independence fast train. The shortfalls of LP have been range limitations to only 300 miles per tank. If this same effeciency is realized with this technology, the range would be increased, and Problem solved. Clean inexpensive LP with long range…sign me up!

  21. Ken L on September 25, 2012 10:22 AM

    Is this engine for real? There isn’t enough explanation to show how it works. Where does the compression and expansion take place? How is the fuel ignited? How is torque produced?

    I agree with Marc that 60% efficiency is not possible. This is still a heat engine that is governed by the same thermodynamics as any internal combustion engine.

  22. Gerald on September 25, 2012 10:47 AM

    This is a twist of the rotary vane engine that’s been around since the early 70’s. There is an article in Popular Mechanics or Popular Science back then of a similar rotary vane engine I remember reading. There must be a technology issue with sealing the vanes because no one after 40 years has one on the market yet.

  23. Razvi on September 25, 2012 12:14 PM

    There are a number of things that does not fit properly.
    1- It seems that the principal is similar to pelton wheel. In hydroelectric there is more energy in and less out.
    2- The fuel is not compressed hence the output power will be very low.
    3- How the fresh fuel remain in and part of the fuel not escape from the last four chambers, espacially from last two chambers?

  24. Dave CAmpbell on September 25, 2012 12:51 PM

    Its clear whoever wrote this fawning crap is not an engineer. Or shouldne be one..

    Baloney. What will we do with 25Kw? Run a BICYCLE?

    The problem with this hoakey alternate stuff is that it pretends it is reality and ignores 100 years of history in automotive.

    The Chevy Geo is an EIGHTY KW engine and thats a little tin can coffin car.

    When you get 400Kw, wake me up.

    Second false statement:

    “There are also all those moving parts, compressing springs and other things gong on. It’s astonishing the modern internal combustion engine is as efficient as it is.”

    The lack of efficiency to anyone who has a REAL engineering background is NOT parasitic losses from valve springs and piston mass.

    It is THERMODYNAMIC losses in the trapped process. Combustion is heat and heat is lost through cylinder walls and out the exhaust. THAT is why the piston IC engine is 30% efficient.

    Belive me, there is NOTHING new in automotive engineering. The best minds there are world wide, have been working on this for 120 years.

    Next false statement:

    “In case you’re wondering why the piston engine isn’t ever going to catch up to turbine types, it’s the working function problems. ”

    So everyone who has made vehicles in the last 100 years has done it wrong? Thats the delusion of “Everyone is wrong but me”

    The REASON we use piston-crank engines is that they are easy to manufacture and reliable. End of story. If it didnt work, wed not be doing it.

    What else is wrong with this article is that it didnt mention the single most interesting aspect of this supposed invention – conservation of HOV. Read Smokey Yunicks 1985 Patent on this subject if you dont understand.

    Another baloney new technology lark to waste money. This is little more than a cross section of a jet engine.

    Again, wake me up when it hits 400Kw

  25. Brian Westenhaus on September 25, 2012 9:26 PM

    25kw is plenty of continuous duty power for generation in personal transport use.

    There aren’t any false statements. The the thermodynamic matter Dave raises is a major issue, though. The MSU press materials imply without suggesting precisely, that the shock wave is a major source of the energy recovered to drive the engine. Whether the claims are so remains to be seen.

    Dave missed the facts on the piston engine dominance of personal transport. Piston driving crankshaft technology is complex, and benefits from over one hundred years of engineering to solve reliability issues. However, the installed manufacturing infrastructure, human capital, and pricing momentum keep the market competitive and improving.

    However turbine technology is a far simpler concept, much more reliable and efficient. The materials costs and the manufacturing sophistication are the barriers to widespread adoption and market share. Its not market worthy to have $50,000 engines in $25,000 priced cars. The REASON we use piston-crank engines is $25,000 cars cost $25,000 rather than $75,000 turbine engined cars.

    When Dr. Mueller releases more info we’ll have another look. There are some basic questions that need answered for grasping how the end users would benefit.


  26. mark wigg on September 25, 2012 1:48 PM

    While Dave Campbell has a few relevant points, I’d like to suggest that his overall attitude is not overly conducive to supporting people who seek to better our situation. After all, if one suggested to a navvy, say, digging a canal: in a hundred yrs there’ll be a machine that’ll do the work of a 50 of u in half the the time. . . Constructive critisism is good, outright cynicism unproductive. ” Carry on,men”

  27. Ratel on September 25, 2012 2:27 PM

    I offer these links to those who doubt




    I dont know the details but it really looks (and sounds) impressive to me

  28. Marty McAllister on September 25, 2012 2:34 PM

    This looks quite a bit like a Tesla turbine. His engine ran and made plenty of power but the materials available then couldn’t hack it.Looks like the problems have been solved. Can I get a small version to build a self recharger for my electric wheelchair?

  29. Brendan A. Creaner on September 25, 2012 2:50 PM

    It’s very hard to avoid scepticism! Much as one would LOVE to see an effective power-source added to the range of possibilities for a Hybrid-Car – this seems like wishful thinking! The unit shown in the CAD drawings would need a big input of energy to ‘spin-up’ to working speed. ALL engines do – but an efficient piston-engine starts to work at around 1 000 RPM and quickly ‘repays’ the starter-motor input. Gas-turbines – especially those with less-than-tight sealing – must be spun-up to around 20 000RPM to start to produce a power-output. THAT would represent a huge drain on the Hybrid’s battery – that’s why aeroplanes use external starters for their jet-engines (except for emergencies)!

    Previous attempts at centrifugal gas-turbines produced very low power-outputs! It’s hard to believe that this design is significantly better – even if the dynamics of its ‘wave’ improves efficiently somewhat.

  30. Brendan A. Creaner on September 25, 2012 3:10 PM

    To be fair to Dr. Mueller and his ARPA backers – one must assume that a sensible project based on perfectly-sound thermodynamics – has been mis-represented by a VERY poor description in this article!

    There’s no detailed analysis of the energy-inputs [such as for compression of the fuel-air mixture], nor even a specific claim of energy-outputs currently attained! Its very vagueness is why some hopeful people have jumped on the bandwagon with delight and others have scorned it as mere fantasy!

    It needs to show MUCH more detailed drawings of components and analysis of the system-efficiency to be taken seriously.

  31. Justajo on September 25, 2012 3:42 PM

    Agree with the naysayers. Another variation – and not much of that – on old ideas. 3 years (at least) and 2.5 million bucks and all we see is CG and still working out proof of concept. I could have a production car getting 100 mpg on the road in less than a year with one-tenth that much. It’s who you know, not what you know, ain’t it?

  32. Barry Russell on September 25, 2012 3:49 PM

    Fred A. Cerra, if the fuel is natural gas you have a strong move toward hydrogen. Its plentiful and burns cleaner than gasoline. MSU doen’t appear to be saying what the fuel is, and I haven’t seen any comments about the seals (I remember my Dad’s Mazda with a Wankel)

  33. RichC on September 25, 2012 9:05 PM

    Bit hokie with the drawing !

    Obviously, the mention of a sonic wave means that molecular compression occurs due to sound waves. Since the chamber does not change in shape or size, that frequency is rigid. ( RPM constrained)
    This makes the engine similar to what is called a pulse jet. Pulse jets cannot be throttled. Pulse jets need pressurized air and fuel to start and function.
    Pulse jets function with the absolute minimum of parts.

    Now study the drawing !
    The incoming fuel and air mixture are in the center. The turbine wheel is turning CCW.
    There are two exhast manifolds, but only one is shown on the top. The bottom is open to show the gas flow. In the first chamber on the left, the exploded gas is exiting (down and left).
    Notice the next chamber ( to it’s right) the gas is exiting and the blue charge is coming into the chamber. This continues until the exhaust is covered. This then starts (?) the sonic compression. This needs compressed fuel/air as well !
    But wait, what if more fuel/air exhausts before that ?
    What if not all burned fuel air exhaust ?
    These are inefficient functions and from the design, are not controlled !
    Obvious that RPM MUST be the regulator.
    What this means is a tremendous loss of efficiency if you are not at the tuned frequency.
    Also means the efficency claims are bogus
    For instance, for a 8 inch diameter disk/wheel you would approach 21,000 + RPM to even approach sonic conditions.
    And the seals need to be perfect !
    Lets see the charts boys

    For the Hydrogen enthusiast…better check the cost of hydrogen ( 12X gasolene) before thinking of that fiasco

  34. Sameer Dudani on September 25, 2012 9:46 PM

    Nice and cheaper alternative to Automotive sector.I got some doubts regarding this

    *How to control combustion of this engine?
    *what wil be its specific power output?
    *is it compatible with Alternative fuels?
    *what is the peak pressure achieved after combustion?

  35. Arthur Holland on September 25, 2012 10:04 PM

    Each blast of fuel will expand in all directions including the reverse. That component will retard the intended direction of rotation.
    A feeble solution.
    Place a shot gun at every input port.
    Aim it tangentially at the fast retreating wall.
    The gun barrel,one hopes, will provide
    a solid reaction to the forward-aiming gun.

    Ricocheting pellets (lumps of gas) hitting the advancing wall,will provide a greater reverse impact than shots at the retreating wall.

  36. RichC on September 25, 2012 10:20 PM

    I had a chance to go back and look at the youtube video’s posted earlier.
    I am impressed with the concept. It is ( sonic compression)a unique approach to solve turbine combustion, which is what I would call this approach.
    I look forward to hearing more from Dr Mueller.
    I see he uses close fits to eliminate gaskets and seals. The operating engine does not match the posted drawing above, but is a single compustion unit.
    By watching the blue flaming exhaust in the first video, you can see that much more work is required to tune it in.

    I await the further work !

  37. JanJ on September 25, 2012 11:02 PM

    So much speculation based on such little information!
    It’s not hard to figure why there is so little hard fact about this – if a full explanation and analysis were available I’d bet that some joker would steal the idea and go somewhere cheap and make zillions of engines…

  38. Rodney Jackson on September 26, 2012 1:54 AM

    There are two points that are niggling me.
    1. If this is a bogus claim, just to keep us all dreaming, then it will never be seen in a car.

    2. If this is a true engine that does as it is claimed, again, we will never see it in a car. Why? If something were that good, the oil companies will snap up the design and shelve it. There is no way an oil company will allow something to cut their share of the Billions of oil dollars worldwide.

    Conclusion: We will never see it in a car.

  39. Saulo Quevedo on September 26, 2012 6:45 AM


    Watching this new engine for shockwave think is the right way because the traditional combustion engines sin by having the lever principle (via pistons and crankshaft) dimencionados in a poor and inefficient.
    The Principle of the Lever here to stay (great efficiency for lower power applied) to be applied for with this new type of engine or even electric Motors.

    Saulo Quevedo

    InovaStar Projects and technological solutions

  40. Shanks on September 26, 2012 7:22 AM

    @Rodney Jackson – You are absolutely right. The reality.

  41. Wamonger on September 26, 2012 7:23 AM

    If this is the same Mueller that was working on the flying car. I would delete this and keep my wallet shut.

  42. Larry Burns on September 29, 2012 2:55 AM

    As we had a lot talks about car runing on its own power. No plug in, No charging, just drive from coast to coast. I know it could be done. but did not have the money to biuld it.
    Will its done someone with money did it and thay are selling it now. You can power your car, your home, your business, your boat.I know you won’t beleave it! and you will try to prove this wrong sorry you can’t, Go to:
    http://www.DeLagostti-Industries.com Thay not it to you but install it. ( remember the long comments on this subject.

  43. Larry Burns on September 29, 2012 3:01 AM

    The end is Thay not only sell it to you but also install it.

  44. Arun on September 29, 2012 10:17 AM

    This innovative concept will change the Automobile world. Let us hope, this new Rotary Shockwave (prototype) Engine becomes a commercial success.

  45. Wm Watt on October 10, 2012 10:21 AM

    It took Mazda 5 yrs to work out the seals on the Wrankel rotary engine. How is this one sealed?

  46. Pete B on November 28, 2012 8:46 PM

    Like the Wrankel(spelling?), it would make a great boat motor. These ideas just seem to evaporate.

  47. John on September 1, 2013 6:27 AM

    “Mueller says they have four working bench prototypes, “We have engines – real, working, good-sized models – running right now.” The MSU research team will turn one of them into a 25-kilowatt disk wave engine and generator package this year,”

    A year later we see nothing and no news of progress. However, this promises to advance vehicle propulsion in a quantum leap is exciting. The engine performance is at constant speeds, so a series-hybrid with the engines turning only a generator is the ideal application.

    In June 2013 a series-hybrid plane flow for the first time, using a light Wankel engine generator and a small electric motor turning the propeller. The plane is very quiet and uses electric batteries to take-off and land. They are suitable for inner-city airports. The Wave Disk would vastly improve efficiency in this setup. It is scalable to 200 seater airliners.

    This will eliminate the need for super expensive high speed rail lines. The planes could be in shuttles taking off by the minutes. These cheap short take off planes could take off from small inner city airport with ski-jump runways served by metro rail stations at the airports for ease of access.

    I look forward to driving a series-hybrid car with a Wave Disk engine. And flying in a plane with one.

  48. Mr Lama on February 28, 2014 3:48 AM

    Different type of thinking and concept are available day by day.Some of them are black mailed by giants and some are black mailing in the name of research and innovation.
    So many free energy devices are shown but no sell in market.Several lab presentation of research and innovation are done but not in production.Why are all these.So I am thinking some are black mailed and some are black mailing to the future innovators.
    Regarding this topic we want to see a visual working proof of principle.So we can convince our knowledge.

  49. Bubba with a B on October 5, 2014 5:21 AM

    If anyone else is still interested in this concept, I think the lack of updates can be reasoned out by reading the details of the ARPA – E (DOE) grant given to Dr. Mueller.

    “Proposed Action Description: Funding will support efforts to develop a new 5-10kW up to 15% thermal efficiency engine…”

    Notice it says UP TO 15% THERMAL EFFICIENCY, which sounds very much like an upper limit to me… 🙁 Most cars on the road are at or slightly beyond that efficiency. They (DOE) have written in their desire to limit efficiency for this engine design in the grant documentation itself.

    I dare you to read it for yourself.


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