Radiative Source
This node models a radiative heat source within the domain.
When the Radiation discretization method is P1 approximation, it adds a source term Q0 to the right-hand side of the equation defining the incident radiation G.
When the Radiation discretization method is Discrete ordinates method, the source term Q0 is divided by 4π to obtain the directional power density to be added in the radiative heat transfer equation.
When the Wavelength dependence of radiative properties is Solar and ambient or Multiple spectral bands, a source term Q0,k can be defined for each spectral band.
Material Type
Select an option in the Material type list to specify if the inputs of the Radiative Source section are defined in the material or spatial frame:
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The default option for the Radiative Source node is Solid, which specifies that the heat source Q0 is defined in the material frame. Because the radiation variables and equations are defined in the spatial frame, the inputs are internally converted to the spatial frame. See Conversion Between Material and Spatial Frames for details.
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The Nonsolid option defines Q0 in the spatial frame. No frame conversion is needed.
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The From material option uses the option selected in the Material type list of the Material Properties section of the material applied on the domain on which the node is active.
This option has no effect when the component does not contain a moving frame because the material and spatial frames are identical in such cases. With a Deformed Geometry or a Moving Mesh interface, the heat transfer features automatically account for deformation effects of the material and spatial frames on heat transfer properties. In particular the effects of volume changes on the density are considered. See Handling Frames in Heat Transfer and Material and Spatial Frames for details.
Radiative Source
Select a Radiative source type from the list:
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For Power density enter a value for the power density Q0. When the Radiation discretization method is Discrete ordinates method, Q0 is divided by 4π to obtain the directional power density q0,j to be added in the radiative heat transfer equation. When the Wavelength dependence of radiative properties is Solar and ambient or Multiple spectral bands, the power density can also be User defined for each band, or set as a User defined distribution.
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For Directional power density (available when the Radiation discretization method is Discrete ordinates method) enter directly a value for the directional power density q0,j. When the Wavelength dependence of radiative properties is Solar and ambient or Multiple spectral bands, the directional power density can also be User defined for each band, or set as a User defined distribution.
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For Energy rate enter a value for the energy rate P0. In this case Q0 = P0⁄V, where V is the total volume of the selected domains. When the Radiation discretization method is Discrete ordinates method, Q0 is divided by 4π to obtain the directional power density q0,j to be added in the radiative heat transfer equation. When the Wavelength dependence of radiative properties is Solar and ambient or Multiple spectral bands, the energy rate can also be User defined for each band, or set as a User defined distribution.
When User defined for each band is selected in any of the options above, set a value for each spectral band in the table displayed underneath. Within a spectral band, each value is supposed to be wavelength-independent.
When User defined distribution is selected in any of the options above, set a value or expression. Any expression is then averaged on each spectral band to obtain a piecewise constant function. If the average value on each band is known, you may use instead the User defined for each band option to avoid the evaluation of the average.
Location in User Interface
Context Menus
Radiation in Participating Media>Radiative Source
Radiation in Absorbing-Scattering Media>Radiative Source
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Physics Tab with Radiation in Participating Media or Radiation in Absorbing-Scattering Media selected:
Domains>Radiative Source