combustion..

OK. Here goes.

Let's assume it to be an everyday internal combustion heat engine made of metals and lubricated by oils, which requires fuel, oxygen (normally derived from air) and a source of ignition to operate.

In any combustion process involving air, oxygen is the accelerator and nitrogen the brake. So as the oxygen percentage to the engine increases and the nitrogen percentage decreases, assuming the same fuel supply rate the net result will be an increase in shaft power for the same size of engine and an increase in engine running temperatures.

The question focusses on flammability, which is related to the oxygen percentage. In air, any fuel has a lower flammable limit and an upper flammable limit, and these figures are widely published, as air is about the same everywhere and readily available. However, these limits open out when oxygen-enriched air is used and vary with pressure, and data on this is less-widely published.

In an engine, though, in the limit of raising the oxygen levels, there must come a point where the structure of the engine starts to degrade as a result of the high oxygen concentration and high temperatures, i.e. the metal, if it is made of metal, will begin to form oxides and simultaneously lose structural strength. Further, any organic lubricants subjected to high temperatures and high oxygen concentrations will deteriorate to the point where they combust, adding to the power though shortening the engine life. Further, with less nitrogen being swept through the engine cooling it, there will come a point where the rising temperature becomes more than the weakest component of the engine can withstand.

The result?

And data on this will only be available to the careful experimenter.

Does that answer the question?

thank u sir.....

You sure paint a pretty picture!