Thank you for your advise. I could fix the Problem by using the gas-volume-fraction instead of the inlet velocity for splitting the gas-phase in 3 secondary phases!Now the calculation is running without errors.

I have another question with respect to the DQMOM inlet-BC. After using Wheeler moment-inversion ANSYS gives abscissas(diameter values) and volume fraction + m4 (both calculatet from the weights and abscissas) for the inlet BC. When using m4 values for inlet BC simulation is running without problems but the sauter diameter from secondary phase is nearly similar. With this flow profile(velocities are similar too). I expect 3 different phases with different flow profiles and sauter diameter. Absciccas here where : QP0 = 13 mm, QP2 = 10, QP3 = 8 mm. PBM options max. Length = 10mm; min. Length = 1mm; reference Length = 6.3 mm

Sauter Diameter is very low in comparison with discrete and QMOM Method (6.7 ans 8 mm).

Is it really enough to give m4 and vof values from moment inversion for inlet BC to define the different secondary phases?