3 ms·
Yes, but the useful energy in a combustion engine comes from that expansion of gas driving the pistons. The heat is, for the most part, just a wasted byproduct.
by Reason077 6y ago
Yes, but the useful energy in a combustion engine comes from that expansion of gas driving the pistons. The heat is, for the most part, just a wasted byproduct. (It can be used for ancillary purposes like heating the cabin).
- dragontamer 6y ago> Yes, but the useful energy in a combustion engine comes from that expansion of gas driving the pistons. Isn't that expansion of gas largely driven by the increase of heat? https://en.wikipedia.org/wiki/Internal_combustion_engine https://en.wikipedia.org/wiki/Internal_combustion_engine Wikipedia lists the ICE as a heat-engine. ------ With that being said: the octane combustion formula has 25 O2 as input and 16 CO2 + 18 H2O as output (and I assume the H2O is mostly water vapor). So that's 25 molecules of gas input -> 34 molecules of gas output. So it seems like more "CO2 + vapor" is created than the number of input O2 molecules. But that only accounts for 34% expansion of the volume of the stroke. (25 mols input -> 34 mols output). The rest of the stroke's power comes from the ideal-gas law: higher temperature means higher pressure and larger volume. Literally the heat generated by the chemical reaction.