BodyRadiation
BodyRadiation models radiative heat transfer between two surfaces.
This component calculates the heat flow due to thermal radiation between two surfaces, represented by node_a
and node_b
. The heat transfer is determined by the Stefan-Boltzmann law, where the net heat flow rate Q
is proportional to the difference between the fourth powers of the absolute temperatures of the two surfaces and the net radiation conductance Gr
. The parameter Gr
encapsulates factors such as surface emissivities, areas, and the view factor between the surfaces. The governing equation is:
Usage
BodyRadiation(Gr, σ=5.670374419e-8)
Parameters:
Name | Description | Units | Default value |
---|---|---|---|
Gr | Net radiation conductance, incorporating view factors, surface areas, and emissivities. | – |
Connectors
node_a
- This connector represents a thermal node with temperature and heat flow as the potential and flow variables, respectively. (Node
)node_b
- This connector represents a thermal node with temperature and heat flow as the potential and flow variables, respectively. (Node
)
Variables
Name | Description | Units |
---|---|---|
ΔT | Temperature difference across the element, calculated as node_a.T - node_b.T | K |
Q | Heat flow rate through the element, positive from node_a to node_b | W |
Behavior
Source
# BodyRadiation models radiative heat transfer between two surfaces.
#
# This component calculates the heat flow due to thermal radiation
# between two surfaces, represented by `node_a` and `node_b`. The heat transfer
# is determined by the Stefan-Boltzmann law, where the net heat flow rate `Q`
# is proportional to the difference between the fourth powers of the absolute
# temperatures of the two surfaces and the net radiation conductance `Gr`.
# The parameter `Gr` encapsulates factors such as surface emissivities, areas,
# and the view factor between the surfaces.
# The governing equation is:
# ```math
# Q = Gr \cdot \sigma \cdot (node\_a.T^4 - node\_b.T^4)
# ```
component BodyRadiation
extends Element1D
# Net radiation conductance, incorporating view factors, surface areas, and emissivities.
parameter Gr::Real
# Stefan-Boltzmann constant (W·m⁻²·K⁻⁴).
final parameter σ::Real(units="W/(m2.K4)") = 5.670374419e-8
relations
Q = Gr*σ*(node_a.T^4-node_b.T^4)
end
Flattened Source
# BodyRadiation models radiative heat transfer between two surfaces.
#
# This component calculates the heat flow due to thermal radiation
# between two surfaces, represented by `node_a` and `node_b`. The heat transfer
# is determined by the Stefan-Boltzmann law, where the net heat flow rate `Q`
# is proportional to the difference between the fourth powers of the absolute
# temperatures of the two surfaces and the net radiation conductance `Gr`.
# The parameter `Gr` encapsulates factors such as surface emissivities, areas,
# and the view factor between the surfaces.
# The governing equation is:
# ```math
# Q = Gr \cdot \sigma \cdot (node\_a.T^4 - node\_b.T^4)
# ```
component BodyRadiation
# Port 'a' for thermal connection
node_a = Node() [{
"Dyad": {
"placement": {"icon": {"iconName": "node_a", "x1": -100, "y1": 400, "x2": 100, "y2": 600}}
}
}]
# Port 'b' for thermal connection
node_b = Node() [{
"Dyad": {
"placement": {"icon": {"iconName": "node_b", "x1": 900, "y1": 400, "x2": 1100, "y2": 600}}
}
}]
# Temperature difference across the element, calculated as node_a.T - node_b.T
variable ΔT::Temperature
# Heat flow rate through the element, positive from node_a to node_b
variable Q::HeatFlowRate
# Net radiation conductance, incorporating view factors, surface areas, and emissivities.
parameter Gr::Real
# Stefan-Boltzmann constant (W·m⁻²·K⁻⁴).
final parameter σ::Real(units="W/(m2.K4)") = 5.670374419e-8
relations
ΔT = node_a.T-node_b.T
node_a.Q = Q
node_a.Q+node_b.Q = 0
Q = Gr*σ*(node_a.T^4-node_b.T^4)
metadata {}
end
Test Cases
No test cases defined.
Related
Examples
Experiments
Analyses