Enter a value or expression for P0 to prescribe it as the heat rate at the selected node of the thermal system.
The heat rate P is defined in function of the difference between the node temperature
T and a specified external temperature,
Text, by mean of a convective thermal resistance,
Rconv:
Set the Area A of the surface of the convective heat flux and define the
Heat transfer coefficient h used to express the convective thermal resistance as:
When From material is selected, choose a material available from the
Materials list.
See the Fluid feature for more details on the settings related to each correlation.
Set the Absolute pressure,
pA. For
User Defined, enter a value or expression. Else, select an
Ambient absolute pressure defined in an
Ambient Properties node under
Definitions. The pressure is used to evaluate the
Fluid material properties and this setting is not available for the
Transformer oil and
Water options.
In addition, enter an External temperature,
Text. For
User defined, enter a value or expression. Else, select an
Ambient temperature defined in an
Ambient Properties node under
Definitions.
Finally, when the Fluid is
Moist air, also set the
External relative humidity,
, and the
Surface relative humidity,
, used to evaluate the material properties.
where A is surface area, and
q0 is computed with the Rohsenow’s correlation, that evaluates the heat flux due to nucleate boiling on a surface immersed in a liquid pool. See
Nucleate Pool Boiling Correlation for details about the correlation. Set the
Area A of the surface of the nucleate boiling heat flux, and select materials from the
Fluid and
Surface lists. When a predefined material (
Water,
Benzene,
n-Pentane, or
Ethanol) is used for the fluid, no additional parameters are required, because the liquid and vapor properties are predefined (at saturation temperature) and the Rohsenow’s correlation parameters
Csf and
s are available for different surface materials. Else, see
Nucleate Boiling Heat Flux (
Heat Flux feature) for details about the settings.
The heat rate P is defined as follows to model resistive heating at the node:
where Re is the electrical resistance and
I is the electric current.
Set a user defined value or expression for the Initial temperature,
Tinit, to be used at initialization, in particular to evaluate the heat transfer coefficient.
Select appropriate options in the Add the following to default results in order to include the following global variables (space-independent) in the default plots: