7.7.1 Requirements and Restrictions

Note the following requirements and restrictions for the GT-Power coupling:

• The flow must be unsteady.

• The compressible ideal gas law must be used for density.

• Each boundary zone for which you plan to define conditions using GT-Power must be a flow boundary of one of the following types:
  • velocity inlet

  • mass flow inlet

  • pressure inlet

  • pressure outlet

  Also, a maximum of 20 boundary zones can be coupled to GT-Power.

• If a mass flow inlet or pressure inlet is coupled to GT-Power, you must select Normal to Boundary as the Direction Specification Method in the Mass-Flow Inlet or Pressure Inlet dialog box. For a velocity inlet, you must select Magnitude, Normal to Boundary as the Velocity Specification Method in the Velocity Inlet dialog box.

• Boundary conditions for the following variables can be obtained from GT-Power:
  • velocity

  • temperature

  • pressure

  • density

  • species mass fractions

  • $k$ and $\epsilon$ (Note that it is recommended that you define these conditions in ANSYS FLUENT yourself, rather than using the data provided by GT-Power, since the GT-Power values are based on a 1D model.)

• Make sure that the material properties you set in ANSYS FLUENT are the same as those used in GT-Power, so that the boundary conditions will be valid for your coupled simulation.

• If your model includes species, make sure that the name of each species in GT-Power corresponds to the Chemical Formula for that species material in the Materials dialog box. Also, recall that ANSYS FLUENT can handle a maximum of 50 species.

• You can install the GT-Power libraries in a directory other than the default location. If the GT-Power libraries are loaded into a non-default location, you need to set the following environment variables:
  • FLUENT_GTIHOME - the GTI installation directory where GT-Power is installed

  • FLUENT_GTIVERSION - the current version of the GTI installation

  GTI is not backwards compatible.