Seeking assistance understanding heat reflection, heat retention and heat transfer again

[frankendat]

Howdy, here is the way I understand the concepts in the title (and "heat transfer is likely a redundancy).

 

Heat reflection = If heat source is directed at heat reflective surface, some heat will be reflected, rather than absorbed. The heat reflective surface will remain at a lower temperature longer than a non heat reflective surface.

 

Heat absorption = If heat source is directed at heat absorptive surface, some heat will be absorbed, rather than reflected. The heat absorption surface will remain at a lower temperature longer than a non heat absorptive surface.

 

There are many commercial offerings of coating claimed to keep underlying material at a lower temperature, but I have been unable to find practical, real world i.e. dummed down information. MY QUESTION (finally) Are there thermal reflective or absorptive coatings that provide greater heat reflection and/or less heat retention than highly polished aluminum? What information and/or calculation was necessary to reach your conclusion?

Edited August 19, 2023 by frankendat
typo

[datzenmike]

Polished aluminum will reflect but inside the engine it's not likely to stay highly polished for long and will become covered with carbon and combustion residue. There are some home applied and baked on ceramic coatings for piston tops, valves and combustion chamber surfaces. Ceramic is not a good heat conductor so it acts as a shield and more heat stays in the combustion chamber where it normally expands the gasses and pushes down on the piston. Takes a load off the cooling and oil systems. More heat does more work and increases the efficiency of the engine. It's a 2-5% increase in efficiency like plugging a hole in your house letting the heat out. Does this help?

[thisismatt]

What about emissivity? A polished part may take longer to heat up due to reflective properties, but it's emissivity is lower than an otherwise dull finish, but same part, so it cools more slowly.