Quote:
Originally Posted by serialk11r
You want maximum heat energy at the top of the piston stroke, not heat being absorbed to break apart molecules that then recombine later when they provide less useful work on the piston.
The only thing I would contemplate coating a piston top (or cylinder head) with is a little bit of thermal barrier coat only if there is extra knock resistance headroom. That raises the surface temperature so less heat is conducted away, but you lose knock resistance.
I.e. if you have an E85 engine and you are okay with only running high octane gasoline or high ethanol fuel in there.
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Hmmm... good point.
However Hydrogen has a MUCH higher flame speed (1.85 vs ~0.4m/s) and
Diffusion coefficient.
So it will get the fuel lit faster.
It also has a much lower quench distance (0.64 vs ~2mm)
So will burn closer to the cylinder walls and piston and head surfaces where it should be more concentrated thx to the Nickel catalyst.
Also, a bit should be be produced in the intake tract wile waiting for the intake valve to open and during intake (much flow) and compression.
Also a lower ignition energy which should ad to getting things lit a bit sooner.
Hopefully these effects would make up for any heat losses during combustion.
Then there's the fact that hopefully you're burning a tiny bit of water, rather than fuel..?
Links:
https://mdpi-res.com/d_attachment/en...ion=1634797654
https://h2tools.org/bestpractices/hy...ed-other-fuels