Support

FlameOne runs entirely on your device. Most questions are about what a number means, or about what a model does not cover — so this page answers those first.

The two manuals

Every screen in the application states its own relation, assumptions, method and range of validity — open Relation and assumptions on any screen. The same material is published here as two documents:

• User manual — what each screen asks for, what it reports, and the conventions that apply everywhere.
• Theory manual — for every screen: what the relation assumes, how it is solved, where it stops applying, and how accurate the answer is known to be.

Both are generated from the application's own module catalogue, not written separately, so neither can describe behaviour the application does not have.

Where the numbers come from

Thermodynamic and transport coefficients are read from NASA’s CEA data files, bundled with the application and unmodified. The thermodynamic file holds 5,425 species records; the transport file holds fitted viscosity and conductivity curves for 66 species. Both are released by NASA under the Apache License 2.0; the licence text and the NOTICE are readable inside the application under About & Licences at the bottom of the sidebar.

Equilibrium composition is solved by minimising Gibbs free energy using element potentials, and the results were checked case by case against NASA’s own published CEA output.

Questions that come up

Why is my flame temperature lower than the book’s?

Check the model selector. Frozen composition holds the products fixed by stoichiometry; it is an upper bound. Equilibrium composition lets them dissociate, and dissociation absorbs heat. Both values are shown at once, and the difference between them is labelled. Also check the air model: textbook air is 0.21 O₂ + 0.79 N₂, while CEA standard dry air contains argon and carbon dioxide. Their molar masses differ by about 0.4%, which is enough to move every number that depends on the air–fuel ratio.

The species name is not found.

Names must match the data file exactly and are case sensitive: CH4, H2, N2. A few contain a comma — C2H2,acetylene is one name, not two.

A field will not accept what I typed.

Invalid input is refused rather than silently turned into zero or clamped into range: the reason appears beside the field and the previous value stays in use. A part-typed number such as -, 1. or 1e is allowed to sit there while you finish it.

Why does one screen have no default value?

The asymptotic laminar flame speed needs a pre-exponential factor, and there is no universal value for it — it depends on the mixture and on the overall reaction order assumed for that mixture. Any number offered as a default would be read as a constant of nature, so none is offered.

Two answers are shown. Which is the right one?

Both. Where a relation has two roots — strong and weak branches, ignition and extinction turning points — the application shows them together rather than choosing one for you. Which one applies is a property of your problem, not of the arithmetic, and the region each solution falls in is named beside it.

Can I get more digits out?

Yes. The screen shows four significant figures because that is what is readable; Export CSV writes 17, which reproduces the underlying double-precision value exactly. Exports also carry the conditions they were computed under, so the file is still interpretable months later.

What the application does not do

• No detailed chemical kinetics and no reaction mechanisms. The reactor and ignition models use a single overall step, which is why a cold inlet gives an enormous ignition Damköhler number: such a mixture really is inert at that temperature under a one-step model. Real mixtures ignite far earlier through chain branching.
• The equilibrium solver is gas phase only. Condensed species are not considered, so soot-forming rich mixtures are incomplete.
• Published flammability limits are measurements, not material constants. They depend on tube diameter, ignition energy, direction of propagation and ambient temperature. The application says so on that screen and does not average sources that disagree.
• No propulsion cycle analysis, and no transient simulation.

System requirements

Desktop	macOS 14 or later
Tablet	iPadOS 17 or later
Network	None. The application never connects to anything.
Account	None.

Contact

Write to softwareone.support@gmail.com. It helps to say which module, what you entered, and what you expected — and if the answer looked wrong, to attach the exported CSV, since it carries the full conditions at full precision.