Detailed Results from the Flame Extinguishment Experiment (FLEX) March 2009 to December 2011
Dietrich, Daniel L., Ferkul, Paul V., Bryg, Victoria M., Nayagam, M. Vedha, Hicks, Michael C., Williams, Forman A., Dryer, Frederick L., Shaw, Benjamin D., Choi, Mun Y., Avedisian, C. Thomas
Experiments: FLEX, FLEX-2, SAME
The Flame Extinguishment Experiment (FLEX) program is a continuing set of experiments on droplet combustion, performed employing the Multi-User Droplet Combustion Apparatus (MDCA), inside the chamber of the Combustion Integrated Rack (CIR), which is located in the Destiny module of the International Space Station (ISS). This report describes the experimental hardware, the diagnostic equipment, the experimental procedures, and the methods of data analysis for FLEX. It also presents the results of the first 284 tests performed. The intent is not to interpret the experimental results but rather to make them available to the entire scientific community for possible future interpretations.
Test conditions.
Extracted from the paper by AI · “Verified” means a person checked it
| Fuel | O₂ | Pressure | Airflow | Sensors | Source | AI conf. | Status |
|---|---|---|---|---|---|---|---|
| Heptane Free-floating droplet |
0.30 | 1.0 atm | Quiescent | LLUV, HiBMs, Color Camera | p. 65 | 95% | Pending |
| Heptane Free-floating droplet |
0.30 | 1.0 atm | Quiescent | LLUV, HiBMs, Color Camera | p. 64 | 95% | Pending |
| Methanol Free-floating droplet |
0.18 | 1.0 atm | Quiescent | HiBMs, LLUV | p. 92 | 90% | Pending |
| Methanol Fiber-supported droplet |
0.18 | 1.0 atm | 3 mm/s translation | HiBMs, LLUV | p. 93 | 95% | Pending |
| Heptane Fiber-supported droplet |
0.24 | 0.70 atm | 3 mm/s translation | HiBMs | p. 127 | 90% | Pending |
| Heptane Free-floating droplet |
0.27 | 0.70 atm | Quiescent | HiBMs, LLUV | p. 128 | 95% | Pending |
| Heptane Free-floating droplet |
0.17 | 532.5 mmHg | Quiescent | LLUV, MDCA | p. 34 | 90% | Pending |
| Heptane Free-floating droplet |
0.17 | 532.2 mmHg | Quiescent | LLUV, MDCA | p. 33 | 90% | Pending |
| Methanol Free-floating droplet |
0.17 | 530.4 mmHg | Quiescent | LLUV, MDCA | p. 34 | 90% | Pending |
| Heptane Free-floating droplet |
0.21 | 764.7 mmHg | Quiescent | LLUV, MDCA | p. 34 | 90% | Pending |
Findings.
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01
Flame size measurement is difficult due to dim flames and noise in LLUV images, with window damage exacerbating the issue.
Detection · p. 14 · AI confidence 95% · Reported · Pending
“The flames are quite dim , and as a result, there is a significant amount of noise in the LLUV images. The damage to the window in the CIR chamber for the LLUV camera made the noise worse for the tests in this report .”
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02
The reported flame dimension represents the outer edge of the OH chemiluminescence.
Detection · p. 14 · AI confidence 95% · Reported · Pending
“The flame dimension detailed in this report repr esents the outer edge of the OH • chemiluminescence.”
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03
Coincident with flame extinction, the droplet shape changed to an oblong or football shape.
Other · p. 64 · AI confidence 90% · Reported · Pending
“Coincident with flame extinction, the droplet became almost football shaped.”
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04
Formation of a large vapor cloud after visible flame extinction is indicative of cool flame burning and extinction.
Other · p. 128 · AI confidence 90% · Reported · Pending
“Sometime after the visible flame extinguished, a large vapor cloud formed. This is indicative of cool flame burning and extinction following visible flame extinction.”
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05
High-frequency oscillations in fiber-supported droplets can lead to high burning rates.
Other · p. 127 · AI confidence 85% · Reported · Pending
“the burning rate was high, probably because of the significant and high -frequency oscillations.”