API

Abstract supertype for boundary conditions on the domain boundary.

Dirichlet boundary condition u = value.

Neumann boundary condition ∂ₙu = value.

Robin boundary condition α*u + β*∂ₙu = value.

Periodic boundary marker.

Prescribed Cauchy traction boundary condition σn = value.

Pressure-outlet boundary condition with exterior pressure p_out.

For Stokes solvers this maps to σn = -p_out n.

Homogeneous traction boundary condition σn = 0.

Advection inflow boundary condition u⋅n < 0: impose transported scalar value.

Advection outflow boundary marker u⋅n ≥ 0: no imposed scalar data.

Container for boundary conditions indexed by side symbols.

Validate periodic side pairing for BorderConditions in dimension N.

Supported dimensions are 1, 2, and 3. Opposite sides must both be periodic or both non-periodic.

Abstract supertype for interface conditions across an internal interface.

Scalar jump condition α₁*u₁ - α₂*u₂ = value.

Flux jump condition β₁*∂ₙu₁ - β₂*∂ₙu₂ = value.

Robin-type jump condition α*[u] + β*[∂ₙu] = value.

2D harmonic anisotropy descriptor for Gibbs-Thomson coefficients.

Stored parameters:

• ϵ: anisotropy amplitude (scalar or callback)
• m: symmetry fold (m=4 by default)
• θ0: orientation offset angle (scalar or callback)
• use_stiffness: when true, Stefan may use stiffness correction 1 + ϵ(1-m^2)cos(m(θ-θ0)) for capillarity.

Gibbs-Thomson thermodynamic correction used by Stefan solvers.

Base isotropic coefficients:

• capillary: curvature coefficient σ_κ
• kinetic: kinetic coefficient μ_Γ

Optional 2D harmonic anisotropy descriptors:

• capillary_anisotropy
• kinetic_anisotropy

The complete interface law is applied by Stefan code as: TΓ = Tm - capillary_eff*κΓ - kinetic_eff*VΓ.

Alloy equilibrium interface descriptor for binary-alloy sharp-interface models.

Stored coefficients:

• k_partition: partition ratio C_{s\Gamma} = k\,C_{l\Gamma}
• T_m: reference melting temperature
• m_liquidus: liquidus slope in T_\Gamma = T_m + m\,C_{l\Gamma}

Container for scalar and flux interface conditions.

Evaluate a boundary/interface value at spatial point x and time t.

v may be:

• Float64 (returned directly),
• a callback (x...),
• or a callback (x..., t).