Where does power come from?

[MadBill]

The efficiency that Smokey was trying to achieve in my estimation was a thing called the latent heat of vaporization. If the fuel that enters the chamber is in liquid form in any significant amount, a significant amount of the heat of combustion is used up to convert the liquid fuel to vapor whether it is burned and contributes to the combustion process or not. By having the fuel heated to a consistent vapor, he could virtually eliminate the process of latent heat. Thereby capturing all the chemical heat contained in the fuel combustion cycle. As noted, the offsetting loss is the reduction in the amount of expansion due to a lack of temperature difference...

Good theory, but gaseous fuels like propane and CNG, when tuned to OEM emission levels (e.g. Bi Fuel GM trucks a few years back), have virtually identical equivalent energy fuel economy* whether they are operating on gasoline or the alternative fuel. (*Which BTW undermines a lot of other claims by Smokey re the hot vapor engine.)

[RednGold86Z]

I read this post when it was new some time ago and didn't refresh my memory by re-reading all the posts, but one thing that seems to come to mind when reading the original topic is the real power process being used when N2O is introduced into the combustion process. Is it really just the increased oxygen or is it the cold spray of nitrogen combined with the oxygen that expands and increases the amount of work completed each cycle? Is there another inert binary gas that could be used instead of nitrogen to introduce into the combustion cycle with the oxygen? You would think that something that expanded more than the nitrogen and gave up the oxygen as freely would work better. If you could use a one to one ratio of oxygen to some inert gas you would increase the oxygen content more, if that is where all the power is truly coming from.

N2O requires extra fuel, by itself. That means the extra Oxygen is used in the combustion process. I think some engines with N2O are running so much nitrous that they get most of the power from nitrous and the nitrous fuel system! The cold dense charge also helps the engine ingest more of whatever is available to ingest, but not enough to double the power of the engine. The ENERGY RELEASE is what makes power. The nitrous is injected to the engine in an open system, so the expansion is mostly lost before it even enters the cylinder. If you found a way to direct inject nitrous to a closed valve cylinder near TDC, there's some amount of energy that can be recovered from the compressed tank and phase change from liquid to gas. Cold nitrous entering a cylinder is going to absorb heat, but that heat also needs to be re-supplied by the combustion, so it's not a net benefit in most cases.

[Kevin Johnson]

The efficiency that Smokey was trying to achieve in my estimation was a thing called the latent heat of vaporization. If the fuel that enters the chamber is in liquid form in any significant amount, a significant amount of the heat of combustion is used up to convert the liquid fuel to vapor whether it is burned and contributes to the combustion process or not. By having the fuel heated to a consistent vapor, he could virtually eliminate the process of latent heat. Thereby capturing all the chemical heat contained in the fuel combustion cycle. As noted, the offsetting loss is the reduction in the amount of expansion due to a lack of temperature difference...

Good theory, but gaseous fuels like propane and CNG, when tuned to OEM emission levels (e.g. Bi Fuel GM trucks a few years back), have virtually identical equivalent energy fuel economy* whether they are operating on gasoline or the alternative fuel. (*Which BTW undermines a lot of other claims by Smokey re the hot vapor engine.)

Probably neglecting the energy provided by the environment to present a fuel in its gaseous state at the ambient experimental conditions?

[dfree383]

Smokey used "steam injection" so no special parts are needed!

Didn't Smokey build some sort of I dunno...hot vapor engine or something he was the only one to figure it out and died without revealing the secret? I read about it in his books.....

Bruce Crower built one.

http://www.motocrossactionmag.com/Main/ ... -2463.aspx

[David Redszus]

Comparing the fuel heat of combustion to the fuel latent heat of vaporization, we find the ratio to be about 130:1.
Specific heat of combustion 1265 btu/lb air
Specific heat of vaporization 9.7 btu/lb air

Inlet charge cooling while being a considerable influence on charge density, has almost no bearing on combustion heat.

[Kevin Johnson]

Just was looking basck through the posts:

He found apparrently while testing on changing gasoline to a vapor was the quicker you could change the fuel's state the more stable the fuel vapor is. Once he found this, the vapor is around 437 degrees I believe for the end point of vaporization, right David?

The fuel distillation end point for pump gasoline is typically around 420F, but is usually much lower for racing fuels. The stability of the fuel vapor would not change but the consistency of the mixture would be more constant (which might be saying the same thing).

Now, once we pass our intake valve though, we can approach the whole sound barrier as far as flow between the valve and the seat, I have conversed about this with others and believe the fuel will reliquify and drop out entering the cylinder. But, one thing I thought, everytime a jet exceeds the sound barrier that white cloud forms, however would that be the same as if going into a cylinder because there is no infinite area around the valve?

The reason that jets produce contrails has nothing to do with the sound barrier. It is simply a matter of water vapor condensation due to the frigid temperature of the upper atmosphere. In an engine inlet tract, we have very little water vapor and no chilling effect due to frigid temperatures. Fuel vapors can, however, return to liquid film form when they strike induction wall surfaces.

http://www.google.com/search?q=jet+brea ... 66&bih=622 shows the typical white cloud forming (versus contrails) -- just so the same phenomenon is being discussed. Ignore the photoshopped lawntractors, et al.

[Kevin Johnson]

IIRC, the problem Smokey's hot air engine had was with the lubricants available at that time. Some automakers were interested but the engine ran so hot that the only oil that would hold up was something used in jet aircraft at $100 a quart back then. They'd never be able to sell $500 oil changes to the public.

That sounds about right.

[Kevin Johnson]

Good theory, but gaseous fuels like propane and CNG, when tuned to OEM emission levels (e.g. Bi Fuel GM trucks a few years back), have virtually identical equivalent energy fuel economy* whether they are operating on gasoline or the alternative fuel. (*Which BTW undermines a lot of other claims by Smokey re the hot vapor engine.)

Did some more reading. My guess is that Smokey happened across complex but felicitous droplet evaporation behavior of fluid mixtures; these affected the combustion efficiency.

http://qirt.gel.ulaval.ca/archives/qirt ... rs/018.pdf

[Fahlin Racing]

dfree383, Thank you for posting that link.

Kevin, the lawnmower is great lol I wish I could mow the lawn that fast. One thing on SMokey's engine is he mentions he tried other fuels for his Hot Vapor design and gasoline became the fuel of choice because he tested and tested and gasoline just came to be the one that worked the best apparently. I agree with 340 on the elimination of the latent heat of vaporization process for a quicker burn cycle. Smokey actually wanted to proceed to a 2nd and third Adiabatic Phase engine as he called it. This was only step one.

This has got me thinking a more on multiple areas of combustion once again. Hmmm

David R wrote

Inlet charge cooling while being a considerable influence on charge density, has almost no bearing on combustion heat.

Would pressurizing a heated charge for the induction stroke with a vapor fuel have the same effect of cooling our air to help ingest more expandable gases?

[maxc]

Interesting but over engineered. http://www.rotaryeng.net/scanabhy1230016.pdf

[Kevin Johnson]

Kevin, the lawnmower is great lol I wish I could mow the lawn that fast. One thing on SMokey's engine is he mentions he tried other fuels for his Hot Vapor design and gasoline became the fuel of choice because he tested and tested and gasoline just came to be the one that worked the best apparently. I agree with 340 on the elimination of the latent heat of vaporization process for a quicker burn cycle. Smokey actually wanted to proceed to a 2nd and third Adiabatic Phase engine as he called it. This was only step one.

This has got me thinking a more on multiple areas of combustion once again. Hmmm

The cited paper* says to ignore the aberrant behavior from the curve of the diesel fuel with additive but I think that may be key to what Smokey was doing. Gasoline is a complex mixture whose constituents would vaporize from the droplets at different rates and temperatures. This means that parcels of atmosphere surrounding the droplets would be of biased composition even to the point of exposure to the flame front. This is different from the complete vaporization of a droplet in a much shorter expanse of time which would tend to have a parcel of mixed constituents like the gasoline. It has been noted that during combustion, droplets burn from the outside surface in but Smokey's treatment would alter the composition and atmosphere surrounding -- and of -- those droplets prior to their combustion. My suggestion is that this is felicitous -- probably in the application of a greater percentage of the available energy earlier in the power stroke. You could have complete combustion in all cases but varying degrees of efficiency of conversion of energy into rotary motion.

I think the closest (that I am aware of but certainly my knowledge is very limited in this subject) approach to this is the use of hydrogen as an elemental gaseous admixture to gasoline that can improve efficiency beyond its fuel value.

* http://qirt.gel.ulaval.ca/archives/qirt ... rs/018.pdf
~~~~~~
Digression:

The whole is greater than the sum of its parts.

We can modify this via the potential mood from linguistics and tie together engineering, philosophy and linguistics.

The horror...

~~~~~~

PETROL-HYDROGEN TRUCK WITH LOAD-CARRYING CAPACITY 5 TONS
A. V. BELOGUB and G. B. TALDA
Institute for Problems in Machinery, Ukranian S.S.R. Academy of Sciences, 2/10 D. Pozharsky St.,
Kharkov 310046, U.S.S.R.
(Received for publication 13 December 1990)


6. CONCLUSION
Bench tests of the ZIL-130 engine [carburetor] equipped with the newly developed fuel supply showed its operation to be much more economic under small and medium loads than the prototype.

As compared with the automobile propelled by petrol, the vehicle using a petrol/hydrogen mixture produces CO less by a factor of 9.2, hydrocarbons by a factor of 1.9 and nitrogen oxides by a factor of 7.1, has economical operation better by 17.5%, and consumes less petrol by 39.5%.

[Kevin Johnson]

Interesting but over engineered. http://www.rotaryeng.net/scanabhy1230016.pdf

Good link to SAE 740600 from 1974, anticipating the work in the USSR (but the Soviets were using essentially waste hydrogen gas from industry). I got the citation from the MIT patent for the plasmatron. I wondered what became of that for some time and finally found a comment that soot generation was an issue during sustained operation.