NO <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si4.svg" display="inline" id="d1e562"> <mml:msub> <mml:mrow/> <mml:mrow> <mml:mi>x</mml:mi> </mml:mrow> </mml:msub> </mml:math> production in a canonical Micromix hydrogen flame
Bibliographic record
Abstract
A direct numerical simulation (DNS) of two reactive hydrogen jets in an air crossflow at representative gas turbine conditions is performed. The thermochemical state nominally corresponds to a non-autoignitive, partially premixed turbulent flame. The analysis focuses on the instantaneous and conditional mean flame structures, and the NO x production mechanism. The results show that the flame along the jet centerline plane features two branches, one stabilized on the leeward side and a second lifted above the jet trajectory. The former is located close to the jet exit where the advective velocity is low due to the recirculation zone and the boundary layer. The hot products of the leeward flame are transported downstream and interact with the windward non-premixed flame branch. An analysis of the flame index indicates that both, non-premixed and premixed, flames coexist and undergo strong interactions. Through reaction pathway analyses, it is demonstrated that the production of NO x over the whole domain proceeds mainly through the thermal (Zel’dovich) route; this is the primary pathway in near-stoichiometric regions, while the N 2 O and NNH routes are locally dominant in lean and rich premixed regions, respectively. Moreover, a post-flame ( T > 1850 K) residence time is used to track the time spent by fluid parcels in regions where thermal-NO prevails. This reveals that large quantities of NO produced through the thermal route near stoichiometry are transported in rich zones, resulting in a strong departure from 1D laminar reference cases.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.003 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.002 | 0.002 |
| Research integrity | 0.001 | 0.002 |
| Insufficient payload (model declined to judge) | 0.003 | 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 teacher head, 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".