Basic component of Radiation
The Heat Radiation component models the thermal radiation emitted between two bodies as a result of their temperatures.
This component has 4 options to express the type of radiation which is defined by the parameter Radiation type.
Additionally, there are several built-in functions for radiation as references.
Refer to the below matrix which shows the implemented options.
Use Correction input
false or true
Two parallel plates
Two long concentric cylinders
The following table is the image of radiation geometry when Radiation type is Use References.
Additionally, if you set Use reference of emissivity for Material 1 / 2 as true, the built-in emissivity data can be used as references.
Refer to the below matrix about the built-in emissivity data.
Brass Oxidized 600oC
Steel Galvanized New
Steel Galvanized Old
Stainless Steel, Polished
Stainless Steel, weathered
Aluminium Heavily Oxidized
Iron, dark gray surface
Iron, plate rusted red
Cast Iron, newly turned
Carbon, not oxidized
Rubber Nat Hard
Fundamental equation is :
Qflow=Gr__act ⋅ σ ⋅ T__a4 − T__b4
The extended equation which is implemented in this library is :
Qflow=cor ⋅ Gr__act ⋅ σ ⋅ T__a4 − T__b4
when Use Correction input = true, cor is specified by the input signal. If Use Correction input = false, cor is the constant value "1".
Net radiation conductance between two surfaces Gr__act is defined based on the selected option. The equation for each option is shown below.
Radiation type : Constant
With this type, the net radiation conductance is specified by the value of parameter Gr.
Radiation type : External input
If you use this type, the net radiation conductance is specified by the signal input Grin.
Radiation type : General
If you use this type, the generalized equation is valid for the net radiation conductance.
The following equation is based on the radiation network for two surfaces which exchange heat each other and no other route of heat.
Radiation type : Use References
If you use this type, references can be used for the net radiation conductance, and there are 4 options.
"Surrounded object" : Radiation Geometry = Surrounded object
"Two parallel plates" : Radiation Geometry = Two parallel plates
"Two long concentric cylinders" : Radiation Geometry = Two long concentric cylinders
"Concentric spheres" : Radiation Geometry = Concentric spheres
Heat flow rate from port a to port b
Temperature of port a
Temperature of port b
Net radiation conductance between two surfaces
Stefan-Boltzmann constant 5.670373e-8
Emissivity of object 1 on port a
Emissivity of object 2 on port b
Thermal port, a
Thermal port, b
if Radiation type is
Input signal of the heat transfer coefficient
if Use correction input is
Input signal of the correction factor for Qflow
Select Type of Radiation
General : Use the generalized equation
Constant : Radiation conductance is constant
External input: Radiation conductance given by input
Use References : Use references for Radiation conductance
Geometry type of Radiation.
Use references of emissivity for Material1
If true, Emissivity for Material 1 are defined by reference data
Use references of emissivity for Material2
If true, Emissivity for Material 2 are defined by reference data
Brass Polished :0.03
Emissivity for Material 1 if Use references of emissivity for Material 1 is true.
Emissivity for Material 2 if Use references of emissivity for Material 2 is true.
emissivity of object 2 on port b
Surface area of object 1
Surface area of object 2
Radius of object 1, Inner
Radius of object 2, Outer
Length of object 1
View factor for Radiation
Use Correction input
If true, input of correction for Gr_act is valid
Heat Transfer Library Overview
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