Experiments / Ground studies
Basic flame science
SPICE soot analysis
Re-analysed more than 1,600 SPICE photographs to extract soot temperatures and compare soot formation with and without gravity.
What burned
Gas
Fed through a small burner
Where
On a computer
A computer study, not a new flight test
How much data
No test table
NASA's archive holds its report, not a table of tests
What they changed between tests
- gravity level
- burner configuration
- model parameters
What it found
Flames make far more soot in microgravity than at normal gravity, and this work tries to explain the gap.
NASA's words
“increase understanding of the issues that control the large discrepancy between soot formation in 1g and in 0g flames” PSI record
Summarized by the SI. Each summary is tied to a quotation that the build checks against NASA's text. A matching quote is not a scientific review.
What it helps with
Stopping a fire from starting
Which materials burn, and in what air
Not an aim
Noticing a fire early
What smoke looks like to a detector
Touches on it
Putting a fire out
What makes a flame go out
Touches on it
For researchers: NASA's full recordThe conditions tested, every row of the table, NASA's description, publications and hardware
Shared hardware: Later studies that took flight data from PSI and built models or follow-up experiments on it. Experiments that shared hardware share its limits, so their results can be compared directly.
Why it counts as fire-safety research
“Other combustion investigations within the PSI database (but not explicitly referenced above) are still relevant to fire safety, just not as strongly or directly.” NASA challenge statement
NASA's words behind each rating
- Prevention0 of 3
Not an aim of this investigation.
- Detection1 of 3
“For space applications, the results support safer fire detection, suppression, and cleaner combustion technologies critical for long-duration missions.”
- Suppression1 of 3
“For space applications, the results support safer fire detection, suppression, and cleaner combustion technologies critical for long-duration missions.”
Conditions covered
- Oxygen in the atmosphere
- not reported
- airMoon
- not in the PSI table
- Pressure
- not reported
- Moonsea level
- not in the PSI table
- Flow speed
- not reported
- not in the PSI table
- Itemized rows
- 0
- no table in PSI
Fuels and materials
Not itemized in PSI.
Measurements named in the PSI record
- Flame imaging
- Pyrometry
- Soot measurement
- Numerical simulation
NASA's description
Objectives
This ground investigation sought to increase understanding of the issues that control the large discrepancy between soot formation in 1g and in 0g flames. The objective of this investigation was to integrate computational and experimental methods to derive temperature distributions and soot volume fractions from the Smoke Point in Coflow Experiment (SPICE) data available in PSI. By analyzing over 1600 raw DSLR images and incorporating advanced soot models, the study sought to improve understanding of soot formation, oxidation, radiative re-absorption, and aggregate growth in heavily sooting flames. The work further aimed to reconcile microgravity and normal gravity flame behavior, identify key physical and chemical processes influencing smoke point development, and provide a framework for evaluating model parameter sensitivity.
Approach
The approach was to combine image processing, experimental diagnostics, and detailed soot modeling. Raw Nikon NEF images were decoded into three color channels and analyzed using color-ratio pyrometry to extract soot temperature fields. Absolute light calibration from SPICE was then used to calculate soot volume fractions. For computational modeling, a coupled flow–species–soot system was implemented, modified to include radiation re-absorption and discrete-sectional aggregate formation. Simulations were performed for both Yale and ACME burner configurations under normal and microgravity conditions. Comparisons between experimental data and computed results guided sensitivity analyses of soot evolution parameters, including the effects of radiation, scattering, boundary conditions, and heat transfer to the burner structure.
Hypothesis
Microgravity conditions would produce longer, more diffuse flames with lower temperatures and increased soot concentrations compared to normal gravity, and that careful integration of experimental temperature fields into the simulations would reduce discrepancies between measured and predicted soot distributions.
Research impacts and Earth benefits
This study sought to enhance understanding of soot formation, flame structure, and radiative transport under microgravity and normal gravity, improving predictive models for combustion in both spacecraft and terrestrial systems. For space applications, the results support safer fire detection, suppression, and cleaner combustion technologies critical for long-duration missions. On Earth, the insights help reduce pollutant emissions, optimize combustion efficiency, and inform the design of cleaner energy and industrial systems.
Publications
1 listed in PSI, 1 with a DOI.
- A Combined Experimental and Computational Study of Soot Formation in Normal and Microgravity Conditions (2022)Dobbins Richard R., Tinjero Jesse, Squeo Joseph, Zhao Xinyu, Hall Robert J., Colket Meredith B., Long Marshall B., Smooke Mitchell D.
Hardware and raw data
7.7 KB of raw data on PSI: metadata 1. FlameLens reads the experimental table, not the raw video or sensor files.
Linked investigations
- SPICE uses its flight data
On Earth
Cleaner combustion: Lower pollutant emissions and cleaner industrial combustion.
“the insights help reduce pollutant emissions, optimize combustion efficiency”