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*FLUID BOUNDARY
Specify boundary conditions for fluid flow analyses.

This option is used to specify boundary conditions for fluid flow analyses. Boundary conditions can be specified as spatially varying or constant with an associated variation in time.

Products: Abaqus/CFD  Abaqus/CAE  

Type: History data

Level: Step

Abaqus/CAE: Load module

References:

Required parameter: 

SURFACE

Set this parameter equal to the name of the surface on which to apply the boundary condition.

Required, mutually exclusive parameters: 

PRESSURE OUTLET

Include this parameter to specify a pressure outlet boundary condition.

SYMMETRIC

Include this parameter to specify a symmetry boundary condition.

VELOCITY INLET

Include this parameter to specify a velocity inlet boundary condition.

WALL

Include this parameter to specify a wall boundary condition.

Optional parameters:

OP

Set OP=MOD (default) for existing *FLUID BOUNDARYs to remain, with this option modifying existing boundary conditions or defining additional boundary conditions.

Set OP=NEW if all existing *FLUID BOUNDARYs applied to the model should be removed. New boundary conditions can be defined.

SLIP

The parameter can be used only if the WALL parameter is included. Set SLIP=NO (default) to indicate a no-slip wall boundary condition. Set SLIP=YES to indicate a slip wall boundary condition.

Data line if the WALL and SLIP=NO parameters are included: 

First (and only) line:

  1. Boundary condition magnitude or distribution name.

  2. Amplitude name (if required).

Data lines if the WALL and SLIP=YES parameters are included: 

First line:

  1. Boundary condition type label VELX, VELY, VELZ, VELXNU, VELYNU, VELZNU, TEMP, TURBKE, TURBEPS, TURBNU, TURBOMEGA, TURBINTENSITY, TURBLENGTHSCALE, TURBVELOCITYSCALE, or TURBVISCOSITYSCALE (see “Active degrees of freedom” in “Boundary conditions in Abaqus/CFD,” Section 34.3.2 of the Abaqus Analysis User's Guide).

  2. Boundary condition magnitude or distribution name.

  3. Amplitude name (if required).

Repeat this data line as often as necessary to specify boundary conditions at the slip wall.

Data lines if the PRESSURE OUTLET parameter is included: 

First line:

  1. Boundary condition type label P, PNU, TEMP, TURBKE, TURBEPS, TURBNU, TURBOMEGA, TURBINTENSITY, TURBLENGTHSCALE, TURBVELOCITYSCALE, TURBVISCOSITYSCALE, or PASSIVEOUTFLOW (see “Active degrees of freedom” in “Boundary conditions in Abaqus/CFD,” Section 34.3.2 of the Abaqus Analysis User's Guide).

  2. Boundary condition magnitude or distribution name. This value is ignored for PASSIVEOUTFLOW.

  3. Amplitude name (if required). This value is ignored for PASSIVEOUTFLOW.

Repeat this data line as often as necessary to specify boundary conditions at the pressure outlet.

Data lines if the VELOCITY INLET parameter is included: 

First line:

  1. Boundary condition type label VELX, VELY, VELZ, VELN, VELXNU, VELYNU, VELZNU, TEMP, TURBKE, TURBEPS, TURBNU, TURBOMEGA, TURBINTENSITY, TURBLENGTHSCALE, TURBVELOCITYSCALE, or TURBVISCOSITYSCALE (see “Active degrees of freedom” in “Boundary conditions in Abaqus/CFD,” Section 34.3.2 of the Abaqus Analysis User's Guide).

  2. Boundary condition magnitude or distribution name.

  3. Amplitude name (if required).

Repeat this data line as often as necessary to specify boundary conditions at the velocity inlet.

There are no data lines if the SYMMETRIC parameter is specified.