It is possible to get a floating point error carrying out multiphase flows, when there is a single continuous phase which is a compressible variable composition mixture.
This is due an uniinitialized variable in the procedure for converting between static pressure and total pressure. Even if the case does not fail, convergence is likely to be adversely affected.
No workaround is currently available.
ANSYS CFX Release 12.0. A custom executable for ANSYS CFX 11.0 SP1 is available on request.