No offense intended, but this thread isn't about perpetual motion machines such as you're wanting to discuss. It's about saving fuel. Discussions about the water device you're referring to (which is a perpetual motion machine and obviously won't work) will simply get this thread locked as on "Overly Speculative Post".Naicamine said:When you use hydrogen as a fuel, the reaction of
combustion: 2 H2 + O2 → 2 H2O produces a certain amount of energy we can call E
Accordingly, as the law states, when you make hydrogen from water, the reaction of
electrolysis: 2 H2O → 2 H2 + O2 requires a minimum amount of energy E.
I know what the law is. However, why is it that you can have a magnet stuck to a surface for years with no supplemental energy source?
Overly Speculative Posts:
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TR345 said:How about diesel water emulsion though. The water is in the fuel as H2o, but H2o does not burn, so somewhere in the combustion process it must be broken up. Why can this be achieved while actually increasing fuel economy? It seems like it would reduce economy if more energy was needed to break it up than gained in this process?
Naicamine said:I know what the law is. However, why is it that you can have a magnet stuck to a surface for years with no supplemental energy source?
brewnog said:Look at Diesel exhaust gas; a very large proportion of that is water vapour. Most of this is a product of combustion, but some is straight from the fuel too. Any hydrogen/oxygen bonds which are broken during combustion are re-made again very, very quickly during the combustion reaction, and still ultimately released as water vapour in the exhaust. Why do you suggest water within the fuel increases fuel economy? Sure, you can inject water into the cylinder to improve efficiency, but this is due to charge cooling effects from evaporation, and not hydrogen/oxygen reaction kinetics.
brewnog said:Look at Diesel exhaust gas; a very large proportion of that is water vapour. Most of this is a product of combustion, but some is straight from the fuel too. Any hydrogen/oxygen bonds which are broken during combustion are re-made again very, very quickly during the combustion reaction, and still ultimately released as water vapour in the exhaust. Why do you suggest water within the fuel increases fuel economy? Sure, you can inject water into the cylinder to improve efficiency, but this is due to charge cooling effects from evaporation, and not hydrogen/oxygen reaction kinetics.
Naicamine said:In a diesel, people have been burning old transmission fluid for years but the emissions is terribly worse than diesel fuel. You can use vegetable oil, or there is even a design to run off of processed tires and roadkill or anything carbon based.
Some people add kerosene to it, but I understand there are possibly ill effects from this.
In a gas motor, most of the same things can be used, but it usually requires that gasoline be mixed into the fuel to thin it out.
"There are numerous benefits to adding water to diesel. Water vaporization increases fuel dispersion in the form of smaller droplets and the contact surface between fuel and air is increased. As a result, combustion is more efficient; combustion temperature peaks are lowered, thereby reducing NOx; and PM formation is reduced."turbo-1 said:Naicamine and TR345, when you make claims about efficiency gains from fuel additives, etc, please include supportive links from reputable sources. This could have been a pretty good thread, but it is degenerating into apocryphal babble, and that is no way to make progress on such a laudable goal.
mtworkowski@o said:Did we talk about the Germans using water injection in their piston driven airplane engines? Is that close to being almost a similar anology of the same thing?
FredGarvin said:I honestly can not see how adding water to fuel can do anything but reduce the deliverable power to the engine. The main thing that water is going to do is draw off some of the energy to vaporize. That energy is unusable for the cycle and goes right out the tail pipe. That exact reason is why we (in aerospace engines) have to have a higher heating value and a lower heating value when dealing with engine performance calculations. I can see how it can help emissions, especially in the realm of NOx formation.
mtworkowski@o said:Was it true that during WWll, Germany had planes that used water injection? I'm thinking high compression, low octane and water as a means of stopping preignition. That's not the story I heard, but you seem to think that any water is bad.
mtworkowski@o said:I'm pretty sure I know that water injection is not the same as mixing water in the fuel. Still, what was the reason for injection and what exactly is charge density? Thanks
FredGarvin said:You're right. They are not the same thing. The water droplets added to the inlet air evaporate and thus draw the heat of evaporation from the inlet air, cooling it and increasing its density.
No. What HE said.brewnog said:What he said.
That would be extremely unsafe. People traveling at much above or below highway speed create higher relative velocities between themselves and other vehicles, which would result in a lot of fatalities. As a motorcyclist, I have found that the ability to accelerate out of a tight spot is just as valuable as having the ability to brake and avoid the tight spot.starkind said:I read about a driving technique called pulse driving reported to get more than 100 mpg in an unmodified factory model car. The idea is to accellerate to highway speed, then turn off the engine and coast down to about 30 mph. Restart the engine and repeat. Any physical truth to this?
Apart from turbo's comments if you turn off the engine in a modern car you lose a LOT of braking and steering performance. You also have to be careful that you don't put the steering lock on!starkind said:The idea is to accellerate to highway speed, then turn off the engine and coast down to about 30 mph. Restart the engine and repeat. Any physical truth to this?