Species Property
A Species Property is used to define and compute a pure species property. The available properties consist of both parameters and functions. Some examples of available parameters are molar mass, Lennard Jones diameter, and dipole moment. Some examples of available functions are density, enthalpy, heat capacity, and viscosity. The property functions created are either dependent on temperature alone, or both on temperature and pressure. For all property functions, the first order derivative with respect to temperature and, when applicable, with respect to pressure are automatically defined. The second-order derivatives with respect to temperature and pressure are available for property functions of density and molar volume.
Right-click the relevant Thermodynamic System node (see FigureĀ 2-8), Predefined System node, or the relevant External Thermodynamic System node, and select Species Property () to start the Species Property Wizard.
The Species Property Wizard contains the following steps:
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Select Properties
First use the Amount base unit list to define the base unit. Select mol or kg.
Use the filter to search among the available properties. Select one or more properties in the list and click the Add Selected button () to add them to the Selected properties list.
Click the Next button () to proceed to the next step, selecting the phase.
Figure 2-13: Species Property Wizard; Select Properties.
Select Phase
Use the list to specify the phase for the species property. The available phases correspond to the ones defined for the thermodynamic system.
Figure 2-14: Species Property Wizard; Select Phase.
Note that for parameters (constants) this step is skipped.
Click the Next button () to proceed to the next step, selecting the species.
Select Species
Select one or more of the species available in the thermodynamic system and use the Add Selected button () to add them to the Selected species table. One property function is created for each of the selected species.
Click the Next button () to proceed to the Species Property Overview in the wizard.
Figure 2-15: Species Property Wizard; the Select Species step.
Species Property Overview
The final step of the wizard presents an overview of the parameters and functions defined for the corresponding property. Click the Finish button () to exit the wizard and add the species property to the current thermodynamic system.
The Species Node Under a System
When creating a species properties, the resulting parameters and functions are collected under a node with the species name. You can create new functions from an existing species node under the system. Right-click the species and select Species Property to start the Species Property Wizard.
Figure 2-16: Create a Species Property from an existing species node.
Settings
Selecting a Species Property node shows the settings for such property.
Figure 2-17: Species Property settings.
Definition:
Shows the definition of a property that is defined as a parameter or a function, for example the name of the parameter or function.
You can use the Parameter name or Function name fields to specify or change the name of a parameter or a function. The section also provides information about the property type and the species it is defined for.
For a parameter, this section also displays the numerical value.
For a function, this sections displays the arguments for the functions and the first order derivatives with respect to these arguments.
Plot Parameters
Available for property functions in order to plot a selected function for a given set of argument values.
Apply a Lower limit and an Upper limit for each argument, and click the Plot button () to plot the function using the given argument range. You can also click the Create Plot button () in order to create a plot group, under the Results node.
Properties Window
To see the reference for constant or temperature dependent functions, right-click on the function and select Properties. This opens the Properties window.
Figure 2-18: Show constant and temperature dependent properties references for species functions.
The reference for the constant or temperature dependent property is available in the Comments field in the Node Properties section.
Figure 2-19: Properties window for species function.