I'm writing a Minecraft mod (for those who don't know, it's sort of like a smaller "program" that loads into the Minecraft game and expands it, by adding other things to it).
My question is: consider a combustion engine that runs on anything that is flammable (even though Uranium has a lot of chemical energy, it can't be set on fire, so it's out).
The engine can burn, for instance, acetone, methane, ethanol, methanol, etc.
By burning these fuels the energy converts their chemical energy into mechanical or kinetic engine to move it's gears, pistons and stuff (whatever the engine uses to transmite the energy).
What is the simplest way of comming up with a "good enough approximation" function
energy = f(fuel)
What goes in this function? the volume of the engine doesn't change, so not that. pressure certainly is a factor (maybe the answer itself?) does it have anything to do with the Ideal Gas Law? What about the density of the fuel, molar mass, specific heat, etc?