Export Unit defines the unit of measurement for the mesh when exported to Ansys Polyflow. Export Unit is available only when Physics Preference is  CFD and the Solver Preference is Polyflow. The default value is Use Project Unit, which means the mesh is not scaled. The available options are Meters, Centimetres, Millimetres, Micrometers, Inches, or Feet. Mesh scales according to your selected export unit.