This module enables you to use a nonlinear extension of the internal Heat Conduction Model and Thermal Integration Model that comes by default in Rocky. In this implementation, both the thermal conductivity and the specific heat are considered functions of the temperature.
The Nonlinear Thermal Contact Model module works by replacing the default thermal model in Rocky by a similar one that accounts for the temperature dependence on thermal properties. Rather than using the built-in values for thermal conductivity and specific heat, this module enables you to define via lookup tables different values for these thermal properties at different temperatures, and the module then interpolates the resulting values.
This module works only if the Thermal Model checkbox is enabled on the Rocky UI, and is not compatible with multi-element (flexible) particles.
For each material that will be used in the simulation, you will need to fill both lookup tables (Specific Heat and Thermal Conductivity) with one or more rows.
In addition, because this module relies on the same code structure used by the Heat Conduction Model and the Thermal Integration Model included in Rocky, enabling this module will therefore override these selections on the Physics | Thermal tab (Figure 28.1: Physics | Thermal tab options when the Nonlinear Thermal Contact Model module is enabled.).
Figure 28.1: Physics | Thermal tab options when the Nonlinear Thermal Contact Model module is enabled.
There are no options to define on the module itself (Figure 28.2: Nonlinear Thermal Contact Model module options.).
There are module-related parameters that you must set for each of your individual Materials. See the section below for details.
When you select a material component under Materials, two new tables will appear to help you define the specific heat and thermal conductivity properties of the material at different temperatures, as shown in Figure 28.3: Nonlinear Thermal Contact Model module options for an individual material component.. You must add at least one row per table. If you choose to add 2 or more rows, the values that you enter can be in any order you wish.
These parameters are explained below:
Specific Heat Table:
Temperature: This defines the temperature of reference related to the specific heat property. Range: [Positive values]
Specific Heat: This defines the specific heat property to be interpolated. Range: [Positive values]
Thermal Conductivity Table:
Temperature: This defines the temperature of reference related to the thermal conductivity property.
Range: [Positive values]Thermal Conductivity: This defines the thermal conductivity property to be interpolated.
Range: [Positive values]
After processing your simulation, you are able to analyze your results using the same thermal-related property that is available for the Rocky Thermal Model:
Temperature (for geometries, particles, and fluids)
Ensure the following:
The Thermal Model checkbox is enabled on the Thermal tab of the Physics entity
The module is enabled. (From the Data panel, select Modules and then from the Data Editors panel, ensure the Nonlinear Thermal Contact Model checkbox is enabled.)
Set up your simulation as you normally would, with the following exceptions:
For the Materials step, for each material that you want to use in your simulation, select it, and then from the Data Editors panel, do the following:
For both the Specific Heat Table and the Thermal Conductivity Table, click the Add button (green plus) to add as many rows to the tables as you want to have points for interpolation.
Note: You must add at least one row in each table.
For each separate row in the table, define the Temperature and your related property value.
Tips:
To insert another row at the bottom of the table, click the Add button.
To remove the selected row, click the Remove button.
To remove all rows in the table, click the Remove All button.
Ensure that you define all thermal-related properties for your geometries and particle inputs.
Process your simulation as you normally would.
When you are ready to analyze your simulation results, you may choose to make use of the following thermal-related Property:
Temperature (for geometries, particles, and fluids)
The Nonlinear Thermal Contact Model module uses a nonlinear extension of the internal Heat Conduction Model and Thermal Integration Model that comes by default in Rocky. This module uses lookup tables to interpolate, using a piece-wise scheme as shown in Figure 28.4: Illustration of a piece-wise scheme., thermal property values at different temperatures; these new values are then used in the equations of Rocky's built-in thermal model.
The piece-wise scheme will search for the backward and forward points based on the particle's current temperature; both specific heat and thermal conductivity properties will be calculated following a linear ramp between the two consecutive points:
 | (28–1) |
where:
is the interpolated value of the particle�s specific heat or thermal
conductivity corresponding to the temperature 
, measured in
[J/kg.K]
or [W/m.K], depending on
the property. 
are the property values (specific heat or thermal conductivity) at the
points that limit the interval inside which the temperature 
is located, measured in
[J/kg.K]
or [W/m.K], depending on
the property. 
is the particle temperature [K]. 
are the temperatures that limit the interval inside which the
temperature 
is located, measured in [K].