How to model a turbulent nozzle
 

Hi there,

i got a problem modeling a turbulent nozzle:
http://img534.imageshack.us/img534/949/aufgabe.jpg

blue is the inlet with BC pressure inlet 240 00 000 Pa.
red is the outlet with BC pressure outlet 100 000 Pa.
material:
destiny 1860 kg/m3
viscosity 5 kg/m*s (very high)

i choose the rng k-epsilon modell but the volume flow is to low.

my question is if its the right model?
which model do you choose for this problem?
which wall function should i use?