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Adiabatic Boundary Condition

An adiabatic condition enforces zero normal heat flux across a boundary:

\[ q_n = -\hat{n} \cdot (\kappa \nabla T) = 0. \]
  • \(q_n\) - outward normal heat flux [W/m\(^2\)]
  • \(\hat{n}\) - outward unit normal
  • \(\kappa\) - thermal conductivity [W/(m K)]
  • \(T\) - solid temperature [K]

Applicability

The adiabatic boundary condition is applied when no heat transfer occurs across a solid boundary. It represents a perfectly thermally insulated surface, for which the normal heat flux vanishes.

Typical use cases

  • Symmetry planes in motor / transformer / electronics sector models — the same plane usually also carries the magnetic symmetry condition.
  • Idealised insulation (foam jackets, thermal blankets) when the conductive loss through the insulator is negligible compared with the rest of the heat budget.
  • Vacuum-facing surfaces where radiation is small and convection absent (e.g. inside a cryostat at moderate ΔT).

Example

condition = AdiabaticBoundaryCondition(
    name = "My Adiabatic Boundary Condition",
    marker = my_marker,
)