4.2.3 Abaqus/CFD output variable identifiers

Products: Abaqus/CFD Abaqus/CAE

References

Overview

Results can be obtained from Abaqus/CFD only by postprocessing.

The tables in this section list all of the output variables that are available in Abaqus/CFD. The output variables can be requested for either field- or history-type output to the output database (.odb) file (see “Output to the output database,” Section 4.1.3). The field type variables can be requested at the nodes, elements, or element faces attached to a surface.

Notation used in the output variable descriptions

The words .odb Field and .odb History following the variable's description indicate the availability of the output variable. The output variable can be written to the respective file if the word "yes" appears after the category name; "no" means that the variable is not available to that file.

Direction definitions

The direction definitions depend on the variable type.

Direction definitions for element variables

For element variables, 1, 2, and 3 refer to the global directions (1=X, 2=Y, and 3=Z). Even if a local coordinate system has been defined at a node (“Transformed coordinate systems,” Section 2.1.5), the data are still output in the global directions.

Direction definitions for nodal variables

For nodal variables, 1, 2, and 3 refer to the global directions (1=X, 2=Y, and 3=Z). Even if a local coordinate system has been defined at a node (“Transformed coordinate systems,” Section 2.1.5), the data are still output in the global directions.

Requesting output of components

Individual components of variables can be requested as history-type output in the output database for X–Y plotting in Abaqus/CAE. Individual component requests are not available for field-type output. If a particular component is desired for contouring in Abaqus/CAE, request field output of the generic variable (e.g., V for velocity). Output for individual components of this field output can then be requested within the Visualization module of Abaqus/CAE.

Element variables

You can request element variable output to the output database file (see “Element output” in “Output to the output database,” Section 4.1.3).

Geometric quantities

COORD

Coordinates of the element centroid for solid elements. These are the current coordinates if the mesh has moved.

.odb Field: yes .odb History: yes

EVOL

Element volume.

.odb Field: yes .odb History: yes

State and field variables

DENSITY

Fluid density.

.odb Field: yes .odb History: yes

DIV

Divergence of the fluid velocity.

.odb Field: yes .odb History: yes

ENSTROPHY

Enstrophy per unit mass.

.odb Field: yes .odb History: yes

HELICITY

Dot product of vorticity and velocity.

.odb Field: yes .odb History: yes

PRESSURE

Fluid pressure.

.odb Field: yes .odb History: yes

TEMP

Fluid temperature.

.odb Field: yes .odb History: yes

Fluid velocity.

.odb Field: yes .odb History: yes

VGINV2

Second invariant of the rate-of-strain tensor (symmetric part of the velocity gradient tensor).

.odb Field: yes .odb History: no

VORTICITY

Curl of the velocity vector.

.odb Field: yes .odb History: yes

VISCOSITY

Element molecular viscosity.

.odb Field: yes .odb History: no

SHEARRATE

Shear rate computed using the second invariant of the rate-of-strain tensor.

.odb Field: yes .odb History: no

Turbulence variables

DIST

Wall-normal distance.

.odb Field: yes .odb History: yes

TURBEPS

Energy dissipation rate.

.odb Field: yes .odb History: yes

TURBKE

Turbulent kinetic energy.

.odb Field: yes .odb History: yes

TURBNU

Turbulent eddy viscosity.

.odb Field: yes .odb History: yes

Nodal variables

You can request nodal variable output to the output database file (see “Node output” in “Output to the output database,” Section 4.1.3).

Geometric quantities

COORD

Coordinates of the node. These are the current coordinates if the mesh has moved.

.odb Field: yes .odb History: no

COORn

Coordinate n (

.odb Field: yes .odb History: no

State and field variables

DENSITY

Fluid density at a node.

.odb Field: yes .odb History: no

DIV

Divergence of the fluid velocity at a node.

.odb Field: yes .odb History: no

ENSTROPHY

Enstrophy per unit mass at a node.

.odb Field: yes .odb History: no

HELICITY

Helicity at a node.

.odb Field: yes .odb History: no

PRESSURE

Fluid pressure at a node.

.odb Field: yes .odb History: no

TEMP

Fluid temperature at a node.

.odb Field: yes .odb History: no

Fluid displacement components at a node.

.odb Field: yes .odb History: no

fluid displacement component (

.odb Field: yes .odb History: no

Fluid velocity components at a node.

.odb Field: yes .odb History: no

fluid velocity component (

.odb Field: yes .odb History: no

VGINV2

Second invariant of the rate-of-strain tensor (symmetric part of the velocity gradient tensor).

.odb Field: yes .odb History: no

VORTICITY

Vorticity components at a node.

.odb Field: yes .odb History: no

VORTICITYn

Vorticity

vorticity component (

.odb Field: yes .odb History: no

SHEARRATE

Shear rate at the nodes computed using the second invariant of the rate-of-strain tensor.

.odb Field: yes .odb History: no

Turbulence variables

DIST

Wall-normal distance.

.odb Field: yes .odb History: no

TURBEPS

Energy dissipation rate.

.odb Field: yes .odb History: no

TURBKE

Turbulent kinetic energy.

.odb Field: yes .odb History: no

TURBNU

Turbulent eddy viscosity at a node.

.odb Field: yes .odb History: no

Surface variables

You can request surface variable output to the output database file (see “Surface output in Abaqus/CFD” in “Output to the output database,” Section 4.1.3). The field output corresponds to the element faces attached to a surface.

Geometric quantities

SURFAREA

Area of a surface. For deforming meshes, it is the surface area in the current configuration.

.odb Field: no .odb History: yes

State and field variables

AVGPRESS

Area-averaged surface pressure.

.odb Field: no .odb History: yes

AVGTEMP

Area-averaged surface temperature.

.odb Field: no .odb History: yes

AVGVEL

Area-averaged surface velocity vector.

.odb Field: no .odb History: yes

FORCE

Total fluid force components on the surface.

.odb Field: no .odb History: yes

HEATFLOW

Integrated normal heat flux on a given surface. Heat flow is considered positive if heat is added to the system and negative otherwise.

.odb Field: no .odb History: yes

HFL

Heat flux vector on a surface.

.odb Field: yes .odb History: no

HFLN

Normal heat flux on a surface.

.odb Field: yes .odb History: no

MASSFLOW

Integrated mass flow rate across a given surface.

.odb Field: no .odb History: yes

NTRACTION

Fluid normal traction on a surface.

.odb Field: yes .odb History: no

PRESSFORCE

Fluid pressure force on a given surface.

.odb Field: no .odb History: yes

STRACTION

Fluid surface (or shear) traction on a surface.

.odb Field: yes .odb History: no

TRACTION

Fluid total traction on a surface. This is equal to the sum of the normal traction (NTRACTION) and the shear traction (STRACTION).

.odb Field: yes .odb History: no

VISCFORCE

Fluid viscous force on a given surface.

.odb Field: no .odb History: yes

VOLFLOW

Integrated volume flow rate across a given surface.

.odb Field: no .odb History: yes

WALLSHEAR

Fluid shear stress magnitude on a surface. It is the magnitude of the shear traction (STRACTION) vector.

.odb Field: yes .odb History: no

Turbulence variables

YPLUS

Wall-normal distance measured in viscous lengths or wall units. A default value of 0 is output for surfaces that are not attached to a wall boundary.

.odb Field: yes .odb History: no

YSTAR

Wall-normal distance scaled using turbulent kinetic energy and viscosity. YSTAR output is available only when TYPE=RNG KEPSILON is specified. A default value of 0 is output for surfaces that are not attached to a wall boundary.

.odb Field: yes .odb History: no

Whole and partial model variables

The output variables listed below are available for part of the model as well as the whole model.

Geometric quantities

VOL

Current volume of the entire set or the entire model.

.odb Field: no .odb History: yes

Total energy output quantities

If the following whole model variables are relevant for a particular analysis, you can request them as output to the output database file (see “Total energy output” in “Output to the output database,” Section 4.1.3). If you do not specify an output region, whole model variables are calculated. When you specify an output region, the relevant energy totals are calculated over the user-specified region.

ALLKE

Kinetic energy.

.odb Field: no .odb History: yes