Page 97 - ansys

5.2.1 Fluid Conditions

A fluid zone is a group of cells for which all active equations are solved. The only required input for a
fluid zone is the type of fluid material. You must indicate which material the fluid zone contains so that
the appropriate material properties will be used.
If you are modeling species transport and/or combustion, you will not select a material here; the
mixture material is specified in the Species Model dialog box when you enable the model. Similarly,
you will not specify the materials for a multiphase flow here; you will choose them when you define the
phases, as described in Section 24.3.4: Defining the Phases for the VOF Model.
Optional inputs allow you to set sources or fixed values of mass, momentum, heat (temperature),
turbulence, species, and other scalar quantities. You can also define motion for the fluid zone. If there
are rotationally periodic boundaries adjacent to the fluid zone, you will need to specify the rotation
axis. If you are modeling turbulence using one of the k-e models, the k-! model, or the Spalart-Allmaras
model, you can choose to define the fluid zone as a laminar flow region. If you are modeling radiation
using the DO model, you can specify whether or not the fluid participates in radiation.

5.2.2 Defining the Fluid Material

To define the material contained in the fluid zone, select the appropriate item in the Material Name
drop-down list. This list will contain all fluid materials that have been defined (or loaded from the
materials database) in the Create/Edit Materials dialog box. If you want to check or modify the
properties of the selected material, you can click Edit... to open the Edit Material dialog box; this dialog
box contains just the properties of the selected material, not the full contents of the standard
Create/Edit Materials dialog box.

90