KNOWN ISSUE: Multiphase modelling and GGI interfaces
As documented in the restrictions for multiphase flow calculations, numerical inaccuracies at GGI interfaces for flows including advanced physical models, such as turbulent dispersion or solids pressure, may be greater than in other applications.
This is due to difficulties with the discretization of the equations for these models at GGI boundaries.
Use of the expert parameter setting 'mpf ggi force flow balance = t' can help in these circumstances.
ANSYS CFX Release 14.0 (by documentation).