FLEX
Flame Extinguishment Experiment
Suppression · CIR / MDCA
Research brief.
From the NASA challenge brief
Studied fire suppression by diluting the chamber atmosphere with carbon dioxide and helium while burning droplets of liquid fuel.
Dynamic Flame Extinguishment
Determine the limiting oxygen index (LOI) for methanol in oxygen-nitrogen-carbon dioxide and oxygen-nitrogen-helium gas mixtures
Develop predictive theoretical and numerical codes and chemical kinetic schemes to model flammability boundaries as a function of effective gravitational acceleration.
AI synthesis.
Across every indexed paper for FLEX
The AI backend isn't connected, so summaries can't be generated right now.
What the experiments revealed.
12 of 17 extracted findings · verified first, then by AI confidence
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01
The limiting oxygen index (LOI) for methanol in oxygen-nitrogen-carbon dioxide and oxygen-nitrogen-helium diluent gases is approximately 12% to 13% oxygen by volume.
Prevention · NTRS 20130014061 · p. 1 · AI confidence 95% · Unverified
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02
The reported flame dimension represents the outer edge of the OH chemiluminescence.
Detection · NTRS 20150023456 · p. 14 · AI confidence 95% · Unverified
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03
Flame size measurement is difficult due to dim flames and noise in LLUV images, with window damage exacerbating the issue.
Detection · NTRS 20150023456 · p. 14 · AI confidence 95% · Unverified
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04
Methanol burns with a very dim blue flame with small standoff distance and little soot production, unlike heptane.
Other · NTRS 20090014812 · p. 2 · AI confidence 95% · Unverified
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05
At high oxygen concentrations, droplets burn to completion rather than exhibiting flame extinction.
Other · NTRS 20090014812 · p. 2 · AI confidence 95% · Unverified
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06
Under quasisteady burning assumptions, initial droplet size should not significantly influence the determination of extinction droplet size.
Other · NTRS 20090014812 · p. 2 · AI confidence 95% · Unverified
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07
Ambient pressure does not significantly influence droplet burning rate but influences chemistry at sufficiently low values.
Other · NTRS 20090014812 · p. 2 · AI confidence 95% · Unverified
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08
The GBEX experiment utilizes a cup burner with a chimney, igniter, and ultrasonic atomizer for oxidizer and agent inlet.
Other · NTRS 20040142357 · p. 1 · AI confidence 90% · Unverified
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09
The FSEE experiment setup includes a chimney, cup burner, chamber, PIV-MZI optics, flow modules, and an ultrasonic atomizer.
Other · NTRS 20040142357 · p. 10 · AI confidence 90% · Unverified
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10
Direct Numerical Simulation (DNS) for the extinguishment study uses full chemistry (GRI Mech 1.2), radiative loss, and mixture rules.
Other · NTRS 20040142357 · p. 10 · AI confidence 90% · Unverified
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11
Water absorption into the methanol droplet during combustion leads to a gradual increase in water concentration; when water mass reaches about 30%, outward water transport begins, lowering the adiabatic flame temperature below the range required for chemical-kinetic gas-phase flame extinguishment.
Suppression · NTRS 20130014061 · p. 3 · AI confidence 90% · Unverified
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12
Methanol droplet extinction occurs via two mechanisms: diffusive extinction due to insufficient residence time at the flame, and radiative extinction due to excessive heat loss from the flame zone.
Suppression · NTRS 20130014061 · p. 1 · AI confidence 90% · Unverified