Shock Wave Engines Could Triple Fuel Efficiency in Hybrid Cars

Ok, I like the concept, but where do you get the 95% drop in carbon dioxide? In the video he does mention emissions often, and I think he is indicating the reduction is due to only running the engine when necessary and it only runs at peak efficiency. I can see how this would be an improvement over ordinary IC engines because they run most of the time over or under peak efficiency. (95% is still incredulous)

Also, the drawing shows the fins are sealing against the outer wall in the combustion quadrant, but in the milled metal part there is a significant amount of space. It could be on the other half you can't see. Or it could work because of the high speed rotation.

Anyone out there know more and care to improve upon my guesses?

My thoughts exactly. Carbon dioxide output is directly proportional to fuel consumption (if it is a hydrocarbon).

To have a 95% reduction in CO2, you would have to have a reduction of 95% in fuel consumption, by definition. Using his figures that fuel economy improves by a factor of 3.5, I calculate a reduction in CO2 of 70%.

You have to wonder about a professor that does not understand this. Then again, there did not seem to be a working prototype either.

Anyone out there know more and care to improve upon my guesses?

The 95% reduction in CO2 is a bit optimistic. We are working with some of these people under a NDA, so are limited in disclosures allowed. Our company goal is to transition to straight 130-proof denatured ethanol fuel for the USA, and these people fit into that plan, along with the use of an alternative igniter to convert current vehicles. But vehicles with a history of gasoline use will need to have us exchange their fuel tanks also. The tanks will be cleaned to remove the deposits and recycled.

130-proof does not have the sensitivity to water absorption that the gasoline blends do, and the flammability issue is reduced. Comparing the emissions of gasoline blends with straight ethanol shows a slight reduction in CO2, but the major reductions are in VOC and NOx. And it goes without saying that the ethanol must be produced from non-food energy crops with high enough yields per acre that food production is not impacted.

Interesting concept.

It's a shame the article or professor doesn't give a bit more detail as to the operation.

So how did they com to the conclusion that 25 KW will drive a SUV or other similarly large vehicle?

Where I am from there are times where I my 285 Hp V10 in my F-250 is not enough like when I am pulling a big trailer on the interstate for a few hundred miles at a shot while pushing a 30+ MPH head wind.

tcmtech -- I've seen "microbuses" in Taiwan many years ago that could by some big stretch of the imagination and some change in styling be called "SUV's". You could actually get 4 adults and possible another child or two into one of them. Motorbikes with similar carrying capacities were common. Of course a motor bike doesn't have walls that constrain (or protect) their cargo. Such a vehicle would do fine on narrow urban streets with a 25 kw motor. We're certainly not talking anything approaching the power the American market wants in something like an SUV. More likely a hybrid motor scooter.

As to shock wave engines? I'll believe it when I see it. I mean 25kw output with a BSFC equivalent to a similar size IC engine for an hour's run. I think the killer of this idea will be practical sealing efficiency and ability of the parts to withstand and reject heat in practical sizes.

The idea of high pressure shock waves in the process suggests that some pretty tricky fuel injection control will be needed to control detonation. Given 2nd law limitations it's hard to visualize how thermal efficiencies in the 40-45% range can ever be achieved. Just because shock wave conditions can reach high theoretical enthalpies in small localized volumes does not mean this can be practically achieved throughout a combustion chamber volume large enough to produce acceptable specific power output.

Also the 15% figure for efficiency suggest an average figure for an engine that runs at widely varying operating points. A diesel cycle engine running at maximum efficiency in the same manner as the proposed shock wave engine will have substantially better efficiency. So the real comparison is much less impressive than the 3 times presented.

My other thought is that the successful execution of this idea if decent thermodynamic efficiency can be achieved will be in a very small engine of ceramic construction. Low thermal expansion coefficients and high temperature capabilities of ceramics favor this approach. On the other hand the close tolerances required will need costly diamond grinding processes.

Success may then depend on how useful power is extracted and the hardware limitations in those components. High reduction gear trains take a toll in efficiency. Electric generators of any kind do not like high temperatures. High temperatures may limit available lubricants to combustion gasses suggesting highly specialized gas film bearings. Not exactly the thing of volume consumer products.

Ed Weldon

Good point Ed, I have often wondered why we don't use a diesel (or multifuel) engine running at peak efficiency to power a generator that charges batteries and runs electric motors that move the vehicle. As long as you are not running at full power up long hills, the engine could power the vehicle and charge the batteries which would provide full power for hills and heavy acceleration. I think this is what Ford did with their hybrid SUV.

I read the article, watched the video, and googled for more into to find out what the physics is that make this engine work. Nada. I even went to the MSU Engineering Dept website and found nothing. There is something vital missing from the description of this engine. Mainly, how it works.

In the diagram and description they provide, the air/fuel mixture gets compressed during the disk rotation from stage 2 to 3 which is what triggers the shockwave. But how? What is causing the compression? Merely sliding a valve closed (blocking the inlets) does not cause compression. The vanes don't move, nor does the chamber in which they spin. A diesel engine, which similarly uses compression rather than a spark to ignite the fuel, actually has a moving piston to cause the compression; merely closing the intake valve in the diesel chamber isn't what triggers the explosion.

So with this disk engine, perhaps if the air/fuel mixture is already under tremendous pressure when injected into the disk chamber, then maybe closing the inlet might trigger a shockwave -- but then the question becomes 'what is the source of energy that is being used to mix the air and fuel at this tremendous pressure?' There must be a mighty compressor feeding the disk chamber. Where is it, and how does its energy usage figure into the overall efficiency?

Something smells a bit fishy to me. Much more info is needed.

I agree that there seems to be something fishy here. The annotated diagram you've copied from the article seems to contain more than the usual proprietary obfuscation. I do not see either why a shockwave occurs at location 2 or why ignition occurs at location 3. I presume that location 3.5 is the time that it takes for combustion to complete. I do not grasp why at location 4 the exhaust gasses would not also expand into the intake manifold as well as the exhaust manifold. This design seems to rotationally accomplish the cycles of a two stroke engine. So the inlet and exhaust gas manifolds will be a critical factor to make this work. I also do not see how the high pressure gasses impart a net torque onto the vanes of this engine. The only time gasses are permitted to expand are during exhaust.

As I implied though, all of my uncertainty may be purely from deliberate obfuscation to protect a patent.

I thought the shockwave could occur because the gasses are moving through the turbine and as the outlet is closed the inertia of the gasses could produce a shockwave as you have gas still moving in as the outlet is closed. This would mean there is a constant flow of air flowing through the inlet to outlet mixing with the exhaust gasses escaping from the combustion section. This is looking more and more like a jet turbine squished and set on it's side. Instead of a compression turbine and combustion section it uses the movement of the gasses through to compress the shockwave. But according to the diagram the inlet seems to close before the outlet?

If the casing were to enclose the outlet as the gasses were going in, I could see my theory working...but still guessing here.

You might be right that it is like 'a jet engine squished and turned on its side'. But that is very similar to the type of jet engine that helicopters use.

Picture from Wiki:

You could be right about protecting a patent, though I did a search of patents and patent applications at the USPO and found 1 patent awarded to him (and others) related to fuel injection and 5 patent applications (filed by him and others) relating to fuel injectors and oil measurement systems for IC engines. I didn't find any patents or applications with his name that concerned a new type of engine.

Sometimes with ARPA involvement the USPO can 'hide' patent disclosures if they relate to secret defense research -- though this could hardly be considered secret now. Except how it is supposed to work.

Hybrid engine combinations are probably greater than 15% efficiency. Tripling their efficiency is not likely to be in the cards. These claims seem to be grandiose.

I at first thought I have away to create the shock wave but after thinking about it a little while, maybe not. At first I thought High intensity high frequency sound would work, but it won't because the motor spins too fast for that. something with a much higher frequency might. But there appears to be a lot (the entire device) that would absorb a RF freq. so maybe not. If the igniter is not a spark but a high freq continuous signal that might be a speed control. That type of ignition would cause a shock wave if you had continuous fuel injection not spurts, and a vapor rather than liquid fuel. Maybe a transducer in a pre injection chamber? I have no idea how one would get seals to work in this scenario. The pictures shown in the article can only be 1/2 of the system. The fuel injector/igniter has to mate with very close tolerances to the shown piece. You can see the machining marks on the shown piece. That is not a good enough finish for the tolerances this would need. The clear plastic cover needs to come off and a high precision "piece" needs to on which will handle the fuel injection, ignition and all the vibration/shock of this thing running plus it will have to handle heat, so cooling will be required. He did ask for three years in the video so maybe. The way I see it the fuel would burn in the center area central to the vanes and the expanding gases would spin the vanes. this requires all air and fuel to be under high pressure going in. I can understand getting it to spin just not efficiently.

This type of ignition would use a lot of power just to keep it running. Wonder if that was included in the efficiency numbers.