One-dimensional flames

Arrhenius.jl provides planar premixed flames, axisymmetric counterflow flames, and catalytic impinging flames. Flame objects are built from a Solution and solved with solve!; the API reference contains all constructors and diagnostics.

Free and burner flames

FreeFlame solves a freely propagating planar premixed flame. Its inlet mass flux, and therefore flame speed, is an eigenvalue. BurnerFlame prescribes inlet mass flux. Both use adaptive spatial grids and support mixture-averaged or multicomponent diffusion, with optional Soret diffusion.

BurnerFlame also supports measured temperature profiles through settemperatureprofile!. The default full-knot policy inserts every supplied profile coordinate. On the conservative, non-Soret path, adaptive refinement adds cells where the profile differs from the cellwise linear chord by more than 1% of the largest supplied temperature. Adaptive profiles require conservative discretization without Soret; enabling Soret restores full knots.

Counterflow and impinging flames

• CounterflowDiffusionFlame models an axisymmetric fuel/oxidizer diffusion flame. Optional radiation models optically thin CO₂/H₂O loss; two-point control supports continuation on a selected branch. Pseudo-arclength continuation adds a fixed-grid bordered corrector and turning-point tracking.
• CounterflowPremixedFlame models opposed premixed streams.
• CounterflowTwinPremixedFlame models a symmetric twin flame from two premixed streams.
• ImpingingJet models an axisymmetric premixed jet directed at an inert wall.

See the examples index for runnable entry points and required input data.

Ionized flames

For mechanisms configured with ionized-gas transport, construct an IonizedFlame through FreeFlame or BurnerFlame. Solve first with charged diffusion frozen, then enable the electric field with setelectricfield!(flame, true) and solve again. The model includes charged species and Gauss's law. Soret diffusion, prescribed temperature profiles, and flame restart snapshots are not supported for this type.

Transport

Multicomponent diffusion and Soret diffusion require collision-integral data exported for the same mechanism. Mixture-averaged diffusion supports mole- or mass-fraction gradients. See solver options for choices and constraints.

Minimal flame calculation

Run from the repository root with the package project activated:

using Arrhenius

gas = CreateSolution("mechanism/h2o2.yaml")
flame = FreeFlame(gas; T=300.0, P=one_atm,
    X="H2:1.1,O2:1,AR:5", width=0.03)
solve!(flame)
println("Flame speed: ", flame_speed(flame), " m/s")