The fluid cavity interaction editor contains the following two fluid type definitions:
Hydraulic; see “Defining hydraulic fluid cavity property options.”
Pneumatic; see “Defining pneumatic fluid cavity property options.”
You should use a hydraulic fluid definition to model nearly incompressible or fully incompressible fluid behavior within a cavity. Hydraulic fluids must include a density, and they may include a bulk modulus and expansion data. For more information, see “Hydraulic fluids” in “Fluid cavity definition,” Section 11.5.2 of the Abaqus Analysis User's Guide.
To define a hydraulic fluid cavity interaction property:
From the main menu bar, select Interaction
PropertyCreate.
In the Create Interaction Property dialog box that appears, do the following:
Name the interaction property. For more information about naming objects, see “Using basic dialog box components,” Section 3.2.1.
Select the Fluid cavity type of interaction property.
Click Continue to close the Create Interaction Property dialog box.
Abaqus/CAE opens the Edit interaction property dialog box.
Choose the Hydraulic fluid definition.
Enter the Fluid density.
In the Fluid Bulk Modulus tab, toggle on Specify fluid bulk modulus to enter a bulk modulus and to allow the entry of temperature and field variable data.
The fluid bulk modulus is required for Abaqus/Explicit and optional for Abaqus/Standard.
Toggle on Use temperature-dependent data to define a fluid bulk modulus that varies with temperature. A column labeled Temp appears in the data table.
To define a fluid bulk modulus that depends on field variables, click the arrows to the right of the Number of field variables field to increase or decrease the number of field variables. Field variable columns appear in the data table.
In the data table, enter the bulk modulus as a function of temperature and field variables. You can enter data into the table using the keyboard. Alternatively, you can click mouse button 3 anywhere in the table to view a list of options for specifying tabular data. For detailed information on each option, see “Entering tabular data,” Section 3.2.7.
In the Fluid Expansion tab, toggle on Specify fluid thermal expansion coefficients to specify expansion data.
Toggle on Use temperature-dependent data to define fluid expansion that varies with temperature. A column labeled Temp appears in the data table.
To define fluid expansion that depends on field variables, click the arrows to the right of the Number of field variables field to increase or decrease the number of field variables. Field variable columns appear in the data table.
If the fluid expansion is dependent on temperature or field variables, enter the Reference temperature for use in calculation of the expansion coefficient.
In the data table, enter the fluid expansion coefficient as a function of temperature and field variables. You can enter data into the table using the keyboard. Alternatively, you can click mouse button 3 anywhere in the table to view a list of options for specifying tabular data. For detailed information on each option, see “Entering tabular data,” Section 3.2.7.
Click OK to create the hydraulic fluid cavity interaction property and to exit the editor.
Pneumatic fluids must include an ideal gas molecular weight; and, for an Abaqus/Explicit analysis, they may include molar heat capacity data. For more information, see “Pneumatic fluids” in “Fluid cavity definition,” Section 11.5.2 of the Abaqus Analysis User's Guide.
To define a pneumatic fluid cavity interaction property:
From the main menu bar, select InteractionPropertyCreate.
In the Create Interaction Property dialog box that appears, do the following:
Name the interaction property. For more information about naming objects, see “Using basic dialog box components,” Section 3.2.1.
Select the Fluid cavity type of interaction property.
Click Continue to close the Create Interaction Property dialog box.
Abaqus/CAE opens the Edit interaction property dialog box.
Choose the Pneumatic fluid definition.
Enter the Ideal gas molecular weight.
For an Abaqus/Explicit analysis, toggle on Specify molar heat capacity, if desired, to include heat transfer data.
If you are specifying molar heat capacity, select either Polynomial or Tabular for the data type.
If you chose Polynomial in the previous step, enter coefficients for the five terms in the polynomial equation—enter zero for any terms that are not needed. If you chose Tabular in the previous step, do the following to complete the data table:
Toggle on Use temperature-dependent data to define fluid expansion that varies with temperature. A column labeled Temp appears in the data table.
To define fluid expansion that depends on field variables, click the arrows to the right of the Number of field variables field to increase or decrease the number of field variables. Field variable columns appear in the data table.
In the data table, enter the molar heat capacity as a function of temperature and field variables. You can enter data into the table using the keyboard. Alternatively, you can click mouse button 3 anywhere in the table to view a list of options for specifying tabular data. For detailed information on each option, see “Entering tabular data,” Section 3.2.7.
Click OK to create the pneumatic fluid cavity interaction property and to exit the editor.