I found a pretty critical issue in your uncertainty analysis. The root-sum-square (RSS) calculation in Eq. (4) mixes the absolute uncertainties of parameters all in different units (seconds, kg/h, bar, °C, ppm, %).
You can’t really combine uncertainties that way; the result (U_total = 1.23) doesn’t have a physical meaning because the units are incompatible. It’s like adding 0.1 seconds + 1 bar + 0.5 ppm and calling it a single number.
This kind of invalidates the entire uncertainty section. To fix it, you’d need to:
Convert each absolute uncertainty to a relative uncertainty (e.g., ±0.5%) first.
Apply the RSS method separately for each derived result (e.g., BTE, BSFC, each emission type).
As it stands, the claim that the overall uncertainty is “within acceptable limits” isn’t supported, which unfortunately casts doubt on the precision of all the measured data. It’s a fundamental stats issue that needs a re-work.