Simulation of Microgravity Diffusion Flames Using Sub-Atmospheric Pressures
Bibliographic record
Abstract
Ethylene/air laminar diffusion flames were studied at sub-atmospheric pressures to simulate a non-buoyant environment and at super-atmospheric pressures for comparison, at fuel flow rates of 0.48 mg/s and 1.16 mg/s. Flame properties including flame geometry, soot formation and temperature field of the flames were studied. Overall, luminous flame height decreased with decreasing pressure to the point of visible luminosity disappearance, resulting in blue flames at a near vacuum. Flame width increased with decreasing pressure until the flame was almost spherical. Soot formation was also found to decrease with decreasing pressure and existed at very negligible concentrations in a near vacuum. Subatmospheric peak soot volume fractions ranged from about 0.1 ppm to 0.93 ppm at 0.48 mg/s, whereas at 1.16 mg/s, peak soot volume fractions were substantially higher. At subatmospheric pressures, higher fuel flow rates produced flames with higher soot concentrations. Soot production was restricted to an annular region with this annular region shifting closer to the flame centerline with increasing height from the burner. At locations about halfway between the burner rim and the flame tip, soot volume fraction decreased with increasing radial distance from the flame centerline. These results are consistent for both high and low pressure flames. The annular soot formation region was also located further from the flame centerline for the higher flow rate flames because of the difference in luminous flame shape. At 0.48 mg/s, the fraction of carbon in the fuel converted into soot was between 0.1 % and 1.2 % in the sub-atmospheric pressure range, from 0.2 atm to 1 atm.
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 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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 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".