On the Non-Equilibrium Behavior of Fuel-Rich Hydrocarbon/Air Combustion Within Perfectly Stirred Reactors
Bibliographic record
Abstract
The observed origins of non-equilibrium behavior, even for relatively large residence times in perfectly stirred reactors (PSRs) burning fuel-rich mixtures, are addressed. These PSR deviations from chemical equilibrium are characterized by using PSR-based results of CO/O2 reacting mixtures. Accordingly, the origins of the PSR non-equilibrium behavior are elucidated by (i) analyzing the relevance of the reaction steps involved in the CO/O2 kinetic mechanism, (ii) deriving and assessing analytical expressions reproducing the PSR results, and (iii) examining asymptotic limit solutions emphasizing a possible cause of the non-equilibrium behavior observed. The main results highlight that the PSR non-equilibrium behavior is controlled by a competition between (i) the rate of progress variable backward component of the CO + O + M ⇌ CO2 + M reaction and (ii) the ratio between the reactor inlet O2 molar concentration and the reactor residence time. Thus, even when the reactor is operating in a region of temperature invariance (plateau), where chemical equilibrium conditions could be presumed, there are some chemical species, such as O2 and O, whose steady state does not correspond to that of chemical equilibrium. It is concluded then that particular attention should be paid when analyzing PSR results obtained at relatively high mixture equivalence ratios, which may not correspond to equilibrium, in situations where it could be presumed to happen. A brief discussion on the extent of such non-equilibrium phenomena is performed as well as using more complex syngas/O2 mixtures.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".