Quote:
Originally Posted by Superturnier
How much does the amount of charge in the cylinder affect to temperature?
Is the amount of mixture more significant than the A/F ratio of the mixture?
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Temperature of what? If you are measuring the temperature of exhaust, the amount of mix is significantly less important than composition. This is why the 'constant EGT climb' method works in small, normally aspirated aircraft.
If you are looking at CHT's and work, it depends. At it's simplest, CHT's depend more on the point of peak pressure than anything else, so the primary impact of the change in mix is the change in the behavior of the flame front and the associated change in the pressure curve.
Regarding lean burn:
I have a coworker who is very experienced in this area. It is very interesting, but the graph is a little deceptive. Picture the NOx line shifted just a tad right. Stoich is more on the rising slope than near peak. So, the drop is not nec. as substantial as it seems on the graph in the article. Also, emissions remains a problem. You have to setup the catalyst reaction to turn the HC's to water and CO2, and it is easily contaminated. That is why things like 'low sulfur' diesel are so important.
Also, in that range particulates soar. The cat cannot clean that type of carbon, so you have the headaches of a DPF setup (I'm actually peripherally involved in the development of a new particulate sensor method now).
Regarding off topic:
Sorry, this stuff should have been split.
Regarding on topic:
I would, with a few caveats, agree with Old Mechanic for a conventional gasoline engine.
-jjf