Quote:
Originally Posted by oil pan 4
Sounds like everything but the HHO was improving fuel economy but the HHO.
Up to 15% is what I would expect from WAI, lean burn and cruise RPM reduction.
|
WITHOUT warm air intake (WAI), lean burn and engine speed reduction, there can be measured gains up to 15% depending on the engine design. This is simply the addition of controlled amounts of HHO along with adjustments in engine timing. The only gain to be seen is the contraction of the wasted "ignition lead" pressure rise as well as post combustion pressure. You will agree that a rapid combustion event is advantageous in reducing the lead time needed to peak combustion pressures after top dead center (TDC). An engine that has a lazy ignition lead of 20 degrees before TDC versus one that needs only 10 degrees will waste energy in negative working pressure.
It is well known that hydrogen accelerates flame fronts. However, most of the classic work is done with hydrogen mixtures of 4% or greater as that is the limit of flammability in air. So what? These tiny HHO generators cannot even begin to approach a production volume that would allow the generator's output to affect combustion in the classic regimes. We must remember that we are adding the small HHO mixture to a combustible hydrocarbon soup. The interaction before combustion is the key.
Government lab work - who's links unfortunately escape me at the moment - show that the addition of ozone in amounts as small as 40 ppm (parts per million) can cause a measurable acceleration in hydrocarbon combustion rates. One of our own forum members, pgfpro, showed with his leaky N2 experiment, that a small amount of N2O2 reduced ignition lead time tremendously. HHO pundits, as well as opponents, tend to forget that O2 gas is also produced and a percentage of this evolves as O3, which, like N2O2 easily dissociates to release oxygen radicals.
These oxygen radicals as well as the H2 gas which easily dissociates into H+ radicals, are usually found after the ignition event has started. Unfortunately, most basic texts on combustion leave the reader with the impression that the carbon and hydrogen in a hydrocarbon chain oxidize in one single step to CO2 and water releasing their potential energy as heat. This is the case only in the simplest of fuel mixtures ( CO and H2 combustion ). The longer and more complex the carbon chain, the more pathways of decomposition it can take before the final ash of combustion is reached. Iso octane with it's C8H18 chain has hundreds of decomposition pathways. Some are exothermic, some are endothermic. And they all feed off each other in a complex dance that is only starting to be fully understood with the aid of supercomputer modelling and advanced detection techniques.
But what if we introduce some of these radicals of combustion before the mixture is ignited? The products of HHO decompose to H+, OH-, HOOH, and so forth - short lived and highly reactive radicals - that fast track the combustion reducing the number of pathways and resulting in a contraction of the needed ignition lead time. In another thread, I asked the readers to make a calculation to see the power gained with just an increase of a few pounds per square inch in the classic BMEP (brake mean effective pressure) formula. It was surprising how a small pressure gain could result in a significant horsepower gain. Imagine recovering just a small amount of the lost pressure rise in an engine's ignition lead and transferring this to the useful area after TDC. With a fast enough combustion event, you can also minimize the exhaust pressure at low horsepower production much as in an Atkinson cycle engine.
By adding sufficient heat and turbulence, you can start the thermal depolymerization of the hydrocarbon fuel even before the start of combustion. This is the principle behind the "hot fuel" engines such as Smokey's Adiabatic engine. Provide enough energy to your fuel mixture, and you don't need HHO to start decomposing the fuel soup and accelerating the combustion. Another forum member, dustyfirewalker, is on the path to an engineering degree and is energetically building a "smoke fueled" engine. I may not agree in detail to his execution, but I do agree in principle - heat up that fuel and air mix and accelerate your combustion.