PSI recordPSI-159Investigation dossier

ACME CFI-G

Advanced Combustion via Microgravity Experiments / Cool Flames Investigation with Gases

Principal investigator: Peter Sunderland
Platform: International Space Station (ISS)
Hardware: ACME, Combustion Integrated Rack (CIR)
Dates: not stated in PSI record
Licence: CC0-1.0
PSI version: v1 · modified 20-Nov-2025
Publications listed: 2

PSI record (opens in a new tab)doi 10.60555/cyt1-kh64 (opens in a new tab)psi.nasa.gov/physci/repo/data/investigations/PSI-159

Evidence proximity, not a safety rating. This page describes what was tested and where each value comes from.

Footprint · Microgravity

Where ACME CFI-G’s runs sit in condition space, in the Atlas chart window. Other investigations’ runs in this regime are dimmed.

179 of 333 runs drawn · 154 runs without O₂ or pressure are not drawn.

Source: NASA PSI run tables (snapshot 2026-11-14) and the published papers listed under Sources. Evidence proximity, not a safety rating; not a hazard map.

Objective

As written in the PSI record:

1. Plan and support flight testing on the International Space Station (ISS). 2. Determine the conditions for which cool diffusion flames occur for propane, n-butane, and n-pentane; normal and inverse flames; and a broad range of Zst, Tad, and fluent flow rate. 3. Support the flight tests with advanced CFD simulations. 4. Identify or develop a chemical kinetics mechanism that yields good agreement between the CFD predictions and the ISS measurements. 5. Disseminate the results as widely as possible.

Fingerprint COMPUTED

Computed from the 333 run rows below: what varied, what was held constant, and what was never recorded.

Varied

O₂ 18.0–40.0 % · 136 levels · measured
Pressure 49.5–331.0 kPa · 11 levels · measured
Tad (K) · 290 values
Zst · 290 values
Peak burner temp (K) · 143 values
Peak burner Temp (C) · 142 values
Xf after test · 141 values
Xf before test · 140 values
XO2 before test · 139 values
XO2 after test · 136 values
+18 more source columns

Held constant

nothing held constant

Not recorded

Flow no flow column in the PSI table
O₂ missing in 154 of 333 rows · inverse flames: O₂ is burner-fed, not ambient

154 inverse-flame runs record a burner-fed oxidizer of 12.0–85.0% O₂. That is the stream fed through the burner, not the surrounding atmosphere, so it is not on the ambient O₂ axis.

Condition axes: what varied and what was held constant
Axis	State	Range	Basis	Recorded
O₂	varied	18.0–40.0 % · 136 levels	measured	179/333
Pressure	varied	49.5–331.0 kPa · 11 levels	measured	333/333
Flow	not recorded	no flow column in the PSI table	not recorded	0/333

Placeable: 179 of 333 record O₂ and can be placed (the engine can compute a distance); 179 also record pressure and appear on the charts. Not placeable: 154: inverse flame: O₂ is the burner-fed oxidizer stream, not the ambient atmosphere.
Gravity: Microgravity (333)
Fuel classes: Gas burner (333)
Flow regime: quiescent (333)
Materials (7): ethane (67) · propane (63) · butane (58) · 30% butane (52) · 30% propane (36) · 50% butane (30) · 30% ethane (27)
Outcomes: self-extinguished (183) · flow-terminated (89) · not-ignited (61)
Measured quantities: Tad — computed (as reported in PSI) [K] (331) · burn time [s] (329) · oxidizer-stream O₂ — inverse flame, not ambient [% O₂ (burner-fed oxidizer)] (154)
Per-run identifiers: Test
Data-quality flags: approximate × 333: The source gives an approximate value or a range; the first value is used.
assumed-value × 333: A value assumed by MARGIN (see the note), not stated in the source.
burner-fed-oxidizer × 154: Inverse flame: the O₂ value is the oxidizer stream fed through the burner, not the surrounding atmosphere.
missing × 154: At least one of O₂, pressure or flow is not recorded in the source row.

Where the runs sit: O₂ × pressure, zoomed to the data

179 of 333 runs record both ambient O₂ and pressure and are plotted. 154 are not: 154 runs: inverse flame: O₂ is the burner-fed oxidizer stream, not the ambient atmosphere.

Microgravity 179 runs

PSI run (larger = several runs at the same condition)
reference atmosphere

Source: the normalized O₂ and pressure of each run in the run table below (NASA PSI run tables or the cited paper); the original cell and any conversion are in each run’s provenance. Reference atmospheres are MARGIN’s presets. Not a hazard map.

Run table

Normalized values with the original cell beneath each. Inspect a row for its conversions, flags, source and distance to your scenario.

ACME CFI-G: 333 runs from PSI-159_Experimental table_CFI-G_Normal Flames.csv, PSI-159_Experimental table_CFI-G_Inverse Flames.csv, showing the first 50.

ACME CFI-G: 333 runs. Each value cell shows the normalized value and, beneath it, the original cell as it appears in the source.
Row	Material	Fuel class	g	O₂ %	Pressure kPa	Flow cm/s	Outcome	Flags
1	ethane	Gas burner	µg	39.40.3939 mole fraction	94.40.9443956 bar	not recordedquiescent—	self-extinguished	approximate, assumed-value
2	ethane	Gas burner	µg	39.00.389822946 mole fraction	94.40.9443956 bar	not recordedquiescent—	self-extinguished	approximate, assumed-value
3	ethane	Gas burner	µg	38.60.386321188 mole fraction	94.40.9443956 bar	not recordedquiescent—	self-extinguished	approximate, assumed-value
4	ethane	Gas burner	µg	38.30.382905163 mole fraction	94.40.9443956 bar	not recordedquiescent—	flow-terminated	approximate, assumed-value
5	ethane	Gas burner	µg	38.00.380426741 mole fraction	94.40.9443956 bar	not recordedquiescent—	flow-terminated	approximate, assumed-value
6	ethane	Gas burner	µg	38.00.379858042 mole fraction	94.40.9443956 bar	not recordedquiescent—	self-extinguished	approximate, assumed-value
7	ethane	Gas burner	µg	37.60.376135171 mole fraction	94.40.9443956 bar	not recordedquiescent—	flow-terminated	approximate, assumed-value
8	ethane	Gas burner	µg	37.30.373391583 mole fraction	94.40.9443956 bar	not recordedquiescent—	self-extinguished	approximate, assumed-value
9	ethane	Gas burner	µg	37.00.369578072 mole fraction	94.40.9443956 bar	not recordedquiescent—	flow-terminated	approximate, assumed-value
10	ethane	Gas burner	µg	36.50.364549879 mole fraction	94.40.9443956 bar	not recordedquiescent—	flow-terminated	approximate, assumed-value
11	ethane	Gas burner	µg	21.00.2101 mole fraction	101.31.0133 bar	not recordedquiescent—	self-extinguished	approximate, assumed-value
12	ethane	Gas burner	µg	21.00.209638709 mole fraction	101.31.0133 bar	not recordedquiescent—	self-extinguished	approximate, assumed-value
13	ethane	Gas burner	µg	18.00.1802 mole fraction	101.31.0133 bar	not recordedquiescent—	self-extinguished	approximate, assumed-value
14	ethane	Gas burner	µg	18.00.179685675 mole fraction	101.31.0133 bar	not recordedquiescent—	self-extinguished	approximate, assumed-value
15	50% butane	Gas burner	µg	39.60.3957 mole fraction	101.31.0133 bar	not recordedquiescent—	self-extinguished	approximate, assumed-value
16	50% butane	Gas burner	µg	39.30.393031985 mole fraction	101.31.0133 bar	not recordedquiescent—	self-extinguished	approximate, assumed-value
17	50% butane	Gas burner	µg	39.10.390548195 mole fraction	101.31.0133 bar	not recordedquiescent—	self-extinguished	approximate, assumed-value
18	50% butane	Gas burner	µg	38.80.388126117 mole fraction	101.31.0133 bar	not recordedquiescent—	flow-terminated	approximate, assumed-value
19	50% butane	Gas burner	µg	38.60.386221513 mole fraction	101.31.0133 bar	not recordedquiescent—	self-extinguished	approximate, assumed-value
20	50% butane	Gas burner	µg	38.30.382509153 mole fraction	101.31.0133 bar	not recordedquiescent—	not-ignited	approximate, assumed-value
21	50% butane	Gas burner	µg	38.30.382509153 mole fraction	101.31.0133 bar	not recordedquiescent—	flow-terminated	approximate, assumed-value
22	50% butane	Gas burner	µg	38.10.381212087 mole fraction	101.31.0133 bar	not recordedquiescent—	not-ignited	approximate, assumed-value
23	50% butane	Gas burner	µg	38.10.381212087 mole fraction	101.31.0133 bar	not recordedquiescent—	flow-terminated	approximate, assumed-value
24	50% butane	Gas burner	µg	38.10.380669262 mole fraction	101.31.0133 bar	not recordedquiescent—	not-ignited	approximate, assumed-value
25	50% butane	Gas burner	µg	23.40.2341 mole fraction	101.31.0133 bar	not recordedquiescent—	self-extinguished	approximate, assumed-value
26	50% butane	Gas burner	µg	23.40.233649188 mole fraction	101.31.0133 bar	not recordedquiescent—	self-extinguished	approximate, assumed-value
27	50% butane	Gas burner	µg	23.30.233254802 mole fraction	101.31.0133 bar	not recordedquiescent—	not-ignited	approximate, assumed-value
28	50% butane	Gas burner	µg	23.30.233254802 mole fraction	101.31.0133 bar	not recordedquiescent—	not-ignited	approximate, assumed-value
29	50% butane	Gas burner	µg	23.30.233254802 mole fraction	101.31.0133 bar	not recordedquiescent—	not-ignited	approximate, assumed-value
30	50% butane	Gas burner	µg	23.30.233254802 mole fraction	101.31.0133 bar	not recordedquiescent—	not-ignited	approximate, assumed-value
31	50% butane	Gas burner	µg	39.30.3926 mole fraction	50.70.50665 bar	not recordedquiescent—	self-extinguished	approximate, assumed-value
32	50% butane	Gas burner	µg	38.50.384638613 mole fraction	50.70.50665 bar	not recordedquiescent—	self-extinguished	approximate, assumed-value
33	50% butane	Gas burner	µg	37.70.377171369 mole fraction	50.70.50665 bar	not recordedquiescent—	self-extinguished	approximate, assumed-value
34	50% butane	Gas burner	µg	36.90.369281404 mole fraction	50.70.50665 bar	not recordedquiescent—	self-extinguished	approximate, assumed-value
35	50% butane	Gas burner	µg	35.90.358532281 mole fraction	50.70.50665 bar	not recordedquiescent—	flow-terminated	approximate, assumed-value
36	50% butane	Gas burner	µg	35.40.35424096 mole fraction	50.70.50665 bar	not recordedquiescent—	not-ignited	approximate, assumed-value
37	50% butane	Gas burner	µg	35.40.35424096 mole fraction	50.70.50665 bar	not recordedquiescent—	flow-terminated	approximate, assumed-value
38	50% butane	Gas burner	µg	35.40.353756802 mole fraction	50.70.50665 bar	not recordedquiescent—	flow-terminated	approximate, assumed-value
39	50% butane	Gas burner	µg	35.30.352937762 mole fraction	50.70.50665 bar	not recordedquiescent—	not-ignited	approximate, assumed-value
40	50% butane	Gas burner	µg	21.00.2097 mole fraction	50.70.50665 bar	not recordedquiescent—	self-extinguished	approximate, assumed-value
41	50% butane	Gas burner	µg	20.90.208586481 mole fraction	50.70.50665 bar	not recordedquiescent—	self-extinguished	approximate, assumed-value
42	50% butane	Gas burner	µg	20.70.207473561 mole fraction	50.70.50665 bar	not recordedquiescent—	self-extinguished	approximate, assumed-value
43	50% butane	Gas burner	µg	20.70.206694811 mole fraction	50.70.50665 bar	not recordedquiescent—	not-ignited	approximate, assumed-value
44	50% butane	Gas burner	µg	20.70.206694811 mole fraction	50.70.50665 bar	not recordedquiescent—	not-ignited	approximate, assumed-value
45	propane	Gas burner	µg	39.50.3954 mole fraction	94.40.9443956 bar	not recordedquiescent—	flow-terminated	approximate, assumed-value
46	propane	Gas burner	µg	39.40.3940449 mole fraction	94.40.9443956 bar	not recordedquiescent—	self-extinguished	approximate, assumed-value
47	propane	Gas burner	µg	39.10.391274328 mole fraction	94.40.9443956 bar	not recordedquiescent—	self-extinguished	approximate, assumed-value
48	propane	Gas burner	µg	38.70.386794842 mole fraction	94.40.9443956 bar	not recordedquiescent—	flow-terminated	approximate, assumed-value
49	propane	Gas burner	µg	38.00.379543758 mole fraction	94.40.9443956 bar	not recordedquiescent—	self-extinguished	approximate, assumed-value
50	propane	Gas burner	µg	37.80.377663625 mole fraction	94.40.9443956 bar	not recordedquiescent—	flow-terminated	approximate, assumed-value

Investigation dossier

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Reading the record, its runs and their sources.