Out-of-Plane Heat Flux
The out-of-plane heat transfer mechanism is used to reduce a model geometry to 2D or even 1D when the temperature variation is small in one or more directions; for example, when the object to model is thin or slender. For the obtained 1D and 2D components, this node adds a heat flux q0, u for the upside heat flux and a heat flux q0, d for the downward heat flux to the right-hand side of the heat equation.
For example, in 2D components, heat transfer in solids and heat transfer in fluids are given by Equation 6-8 and Equation 6-9:
(6-8)
(6-9)
The convective heat flux adds the following contribution
Upside Inward Heat Flux
The available options in the Flux type list are General inward heat flux, Convective heat flux, and Nucleate boiling heat flux. The settings are the same as for the Heat Flux node.
Downside Inward Heat Flux
The available options in the Flux type list are General inward heat flux, Convective heat flux, and Nucleate boiling heat flux. The settings are the same as for the Heat Flux node.
The Out-of-Plane Heat Flux feature is disabled when at least one of the multiphysics couplings (Heat Transfer with Surface-to-Surface Radiation, Heat Transfer with Radiation in Participating Media, Heat Transfer with Radiative Beam in Absorbing Media) is active while solving on the same domain. This is noticed through a warning node displayed under Compile Equations. The radiation interfaces assume an infinite medium in the out-of-plane direction, they are thus not compatible with these features.
See Out-of-Plane Heat Transfer for the formulation of out-of-plane heat transfer in 1D, 1D axisymmetric, and 2D geometries.
See also Out-of-Plane Domain Fluxes.
Upside and downside settings can be visualized by plotting the global normal vector (nx, ny, nz), that always points from downside to upside. Note that the normal vector (ht.nx, ht.ny, ht.nz) may be oriented differently.
See Tangent and Normal Variables in the COMSOL Multiphysics Reference Manual.
Out-of-Plane Heat Transfer for a Thin Plate: Application Library path Heat_Transfer_Module/Verification_Examples/thin_plate
Location in User Interface
Context Menus
Heat Transfer in Solids and Fluids>Out-of-Plane>Out-of-Plane Heat Flux
Heat Transfer in Porous Media>Porous Medium>Fluid>Out-of-Plane Heat Flux
Heat Transfer in Porous Media>Porous Medium>Porous Matrix>Out-of-Plane Heat Flux
Ribbon
Physics tab with interface as Heat Transfer in Solids and Fluids, or any version of the Heat Transfer interface selected:
Domains>interface>Out-of-Plane Heat Flux
Physics tab with Porous Medium>Fluid or Porous Medium>Porous Matrix selected in the model tree:
Attributes>Out-of-Plane Heat Flux