Catching The Wave
Sounds pretty amazing to me. According to Carnot the efficiency of an ideal engine is 1 - Tc/Th. Where Tc is the exhaust temperature and Th is the burning temperature (this is somewhat simplified). The temperatures are absolute (i.e. Kelvin scale in the metric system). The Wave Engine according to some designs operates at a peak temperature of 1070°K with an exhaust at 300°K (room temperature roughly). So what is the ideal efficiency for such an engine? 1 - (300/1070) multiplied by 100 to get percent. And the answer is almost 72%. So a practical realization giving 60% efficiency is not unreasonable. That is about 83% of ideal. Not bad. In fact very good.

Some geeks (not as geeky as me) have a few words to say.

Mueller envisions his wave disc motor powering a generator, making it an ultra-light ultra-efficient hybrid electric vehicle. That's a lot of ultras, but Mueller says he has the numbers to back it up. The wave disc apparently uses 60% of its fuel for propulsion, compared to 15% of fuel used for propulsion in conventional engines. And because the wave disc powered cars would be much lighter -- perhaps 20% lighter -- the fuel efficiency is even greater.

This all might seem very pie-in-the-sky, and that's quite understandable. However, Mueller's team has received $2.5 million in federal dollars from the Advanced Research Projects Administration - Energy (ARPA-E), which will be put towards creating a 25kw engine perhaps as early as next year. According to Mueller, that's enough power to run an SUV.

I'm hoping Mueller's checked his math on this, because I am very excited to have a car running on something as efficient as it is elegant.

Well I checked the math and it doesn't look out of the question. Some folks from Warsaw, Poland and Zurich, Switzerland [pdf] have checked the math with computerized flow simulations and think it looks pretty good. The concept goes back to at least 1906. So it is not a new idea. What is new is this particular realization. And of course we have computers for simulation and automated milling machines to make prototypes and small production volumes. Things not available in 1906.

Of course the engine is just the beginning. Once that is proved you have to design the whole hybrid drive train. And then you have to wrap an automobile around it. I don't expect to see them on the market as a production vehicle for about ten years. Unless some really big money (or the Japanese) get behind it.

Some more places to visit to get a handle on the technology:

Daily Tech

Green Cars

Cross Posted at Power and Control

posted by Simon on 04.15.11 at 06:50 AM


I wish someone had a decent, large-scale drawing that would allow a better understanding of the flows through the engine. Very frustrating.

If I recall correctly, the problem that prevented wide-spread adoption of the Wankel engine was the failure of the seals on the rotor. It took Mazda sometime to figure how to make engines that would last more than a few thousand miles. From the bad drawings on line, it looks like this engine will have very serious seal problems, too.

I doubt very much whether they will get 60% thermodynamic efficiency, 40 to 50% is more likely. But that is really very good, better than diesel. And combined with light weight and regenerative braking a very efficient urban car is likely.

bob sykes   ·  April 15, 2011 8:42 AM


Also note that the drawing doesn't look much like the metal piece in the video.

The pdf is not bad in giving some more details.

M. Simon   ·  April 15, 2011 8:54 AM

Agree with Bob.

For some interesting alternative (and more mature) applications, look at This company has been working on similar technical issues for more than a decade in compressor/expanders and more recently turbines. The core technology is called a toroidal intersecting vane machine (TIVM).

chuckR   ·  April 15, 2011 9:36 AM
M. Simon   ·  April 15, 2011 10:37 AM


I looked at the TIVM and it doesn't look to be any further along than the wave disk. Maybe not even as far along.

M. Simon   ·  April 15, 2011 10:46 AM
M. Simon   ·  April 15, 2011 10:56 AM
The Wave Engine according to some designs operates at a peak temperature of 1070°Kan exhaust at 300°K (room temperature roughly).

I'm not sure I believe that's possible for an engine intended to run for decades, at least not without fairly exotic (and therefore expensive) materials.

Still, interesting.

TallDave   ·  April 22, 2011 9:35 AM

Post a comment

April 2011
Sun Mon Tue Wed Thu Fri Sat
          1 2
3 4 5 6 7 8 9
10 11 12 13 14 15 16
17 18 19 20 21 22 23
24 25 26 27 28 29 30


Search the Site


Classics To Go

Classical Values PDA Link


Recent Entries


Site Credits