Fluid sections are used to define the section properties of a fluid material in an Abaqus/CFD model. For more information, see Chapter 30, “Fluid dynamic analyses.”
To specify homogeneous fluid section properties:
From the main menu bar, select Section
Create.
A Create Section dialog box appears.
Tip:
You can also click Create in the Section Manager or select the create section tool 
in the Property module toolbox.
Enter a section name. For more information on naming objects, see “Using basic dialog box components,” Section 3.2.1.
Select Fluid as the section Category and Homogeneous as the section Type, and click Continue.
The fluid section editor appears.
Select a material for the fluid section. If desired, click 
to create a material; see “Creating or editing a material,” Section 12.7.1, for more information.
Click OK to save your changes and to close the fluid section editor.