Convection Boundary Condition¶

The convection boundary condition models heat transfer between a solid surface and a surrounding fluid through convection. The convective heat flux at the boundary is described by Newton’s law of cooling: $$ q_n = -\hat{n} \cdot(\kappa \nabla T) = h (T - T_\text{amb}). $$

$q_n$ - outward normal heat flux [W/m$^2$]
$\hat{n}$ - outward unit normal
$\kappa$ - thermal conductivity [W/(m K)]
$h$ - convective heat transfer coefficient [W/(m$^2$K)]
$T$ - solid surface temperature [K]
$T_\text{amb}$ - ambient fluid temperature [K]

Applicability¶

This boundary condition is applicable when heat transfer between the solid and the surrounding fluid is dominated by convection and the detailed fluid dynamics are not explicitly modeled. The influence of the fluid is represented solely by the coefficient $h$ and the reference temperature $T_\text{amb}$.

Typical use cases¶

Cooling/heating of solids exposed to air or liquid flow
External natural or forced convection

Example¶

condition = ConvectionBoundaryCondition(
    name = "My Convection Boundary Condition",
    marker = my_marker,
    convection_efficiency = 7.0,
    temperature_medium = 343.0,
)