Heat Transfer Analysis with Moving Frames
This section discusses heat transfer analysis with moving frames, when spatial and material frames do not coincide.
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Material and Spatial Frames
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About Frames in the COMSOL Multiphysics Reference Manual
When the Enable conversions between material and spatial frame check box is selected in the Advanced Settings section, all heat transfer interfaces account for deformation effects on heat transfer properties.
The entire physics (equations and variables) are defined on the spatial frame. When a moving mesh is detected, the user inputs for certain features are defined on the material frame and are converted so that all the corresponding variables contain the value on the spatial frame.
Conversion Between Material and Spatial Frames
This subsection contains the list of all heat transfer nodes and the corresponding definition frame:
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Physics Feature Nodes and Definition Frame
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Definition Frame of Domain Nodes
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Definition Frame of Boundary Nodes
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Definition Frame of Edge and Point Nodes
Physics Feature Nodes and Definition Frame
The following explains the different values listed in the definition frame column in Table 3-6, Table 3-7, Table 3-8, and Table 3-9:
Material:
The inputs are entered by the user and defined on the material frame. Because the heat transfer variables and equations are defined on the spatial frame, the inputs are internally converted to the spatial frame.
Spatial:
The inputs are entered by the user and defined on the spatial frame. No conversion is done.
Material/(Spatial):
For these physics nodes, select from a menu to decide if the inputs are defined on the material or spatial frame. The default definition frame is the material frame.
(Material)/Spatial:
For these physics nodes, select from a menu to decide if the inputs are defined on the material or spatial frame. The default definition frame is the spatial frame.
N/A:
There is no definition frame for this physics node.
Definition Frame of Domain Nodes
Table 3-6: Domain Physics Nodes for Frames
Node Name
Definition Frame
Bioheat
Material
Biological Tissue
Material
Building Material
Spatial
Change Cross Section
Spatial
Change Thickness
Spatial
Fluid
Spatial
Geothermal Heating
Material
Heat Source
Material/(Spatial)
Immobile Fluids
Spatial
Infinite Elements
Spatial
Initial Values
Spatial
Isothermal Domain
Spatial
Opacity
N/A
Out-of-Plane Heat Flux
Spatial
Out-of-Plane Radiation
Spatial
Phase Change Material
Spatial
Porous Medium
Material (Solid part) Spatial (Fluid part)
Pressure Work
Spatial
Radiation in Participating Media
Spatial
Solid
Material
Thermal Dispersion
Spatial
Thermoelastic Damping
Spatial
Translational Motion
Material
Viscous Dissipation
Spatial
Definition Frame of Boundary Nodes
Table 3-7: Boundary Physics Nodes for Frames
Node Name
Definition Frame
Boundary Heat Source
Material/(Spatial)
Continuity
Spatial
Continuity on Interior Boundary
Spatial
Diffuse Mirror
Spatial
Diffuse Surface
Spatial
Fracture
Material (Solid part) Spatial (Fluid part)
Heat Flux
(Material)/Spatial
Incident Intensity
Spatial
Inflow Heat Flux
Spatial
Isothermal Domain Interface
Spatial
Layer Heat Source
Material
Opaque Surface
Spatial
Open Boundary
Spatial
Outflow
N/A
Periodic Condition
Spatial
Prescribed Radiosity
Spatial
Radiation Group
N/A
Symmetry
N/A
Temperature
Spatial
Thermal Contact
Material
Thermal Insulation
N/A
Thin Film
Spatial
Thin Layer
Material
The definition frames of the corresponding pair features are identical to the ones of the standard features.
Definition Frame of Edge and Point Nodes
Table 3-8: Edge and Point Nodes for Frames
Node Name
Definition Frame
Line Heat Source
Material/(Spatial)
Line Heat Flux
(Material)/Spatial
Point Heat Flux
Spatial
Point Heat Source
Material
Surface-to-Ambient Radiation
Spatial
Temperature
Spatial
Thin Rod
Material
Table 3-9: Heat Transfer in thin shells nodes
Node Name
Definition Frame
Change Effective Thickness
Spatial
Change Thickness
Spatial
Heat Flux
Spatial/(Material)
Heat Source
Material/(Spatial)
Initial Values
Spatial
Surface-to-Ambient Radiation
Spatial
Temperature
Spatial
Thin Conductive Layer
Material
Thin Layered Shell
Material