You specify the prescribed conditions for the fluid model in the Load module. You can specify fluid predefined fields in the initial step of a fluid analysis, and you can specify loads and boundary conditions for a fluid model in a fluid analysis step. Depending on the analysis, you may need to specify the following prescribed conditions:
Predefined fields
The predefined field types available for fluid analyses include fluid density, fluid thermal energy, fluid turbulence, and fluid velocity. For more information, see “Initial conditions in Abaqus/CFD,” Section 34.2.2 of the Abaqus Analysis User's Guide.
A density value is required; however, if you do not specify the initial fluid density, the material density definition is assumed.
For an incompressible fluid dynamic analysis that includes an energy equation, you must define the initial fluid temperature.
For an incompressible fluid dynamic analysis that specifies a turbulence model, you must define the initial fluid turbulence values, such as the turbulent eddy viscosity.
The initial velocity is assumed to be zero if no value is specified.
Loads
The load types available for fluid analyses include body force, gravity, body heat flux, and porous drag body force. The fluid reference pressure can be used to specify the hydrostatic pressure level for incompressible flows if there is no pressure boundary condition prescribed. For more information, see the following sections:
Boundary conditions
Boundary conditions types available for fluid analyses include displacement/rotation, fluid inlet/outlet, and fluid wall condition. For more information, see “Boundary conditions in Abaqus/CFD,” Section 34.3.2 of the Abaqus Analysis User's Guide.
You specify boundary conditions to define flow and thermal conditions on the fluid domain boundaries.
You can specify pressure or velocity boundary conditions.
For an incompressible fluid dynamic analysis that includes an energy equation, you can define the temperature or heat flux.
