CFD Online Discussion Forums

CFD Online Discussion Forums (
-   Fluent Multiphase (
-   -   Convergence problems with Wet Steam Model (

eromon84 August 11, 2013 23:51

Convergence problems with Wet Steam Model

I am trying to simulate a turbine model using the Wet steam fluent model.
I am having numerous problems with the boundary conditions I specify.

I have very high inlet pressures.

Operating Pressure set to 0.

Pressure inlet:

Supersonic / initial gauge pressure : 31 77589 Pa ( 31.8 bar )
Gauge Pressure : 30 00000 Pa ( 30 bar )
Total temperature: 570 K

Pressure Outlet:
Gauge Pressure: 1.37 bar
Total backflow Temperature: 394.155 K

when I try to initialize the solution I get the following errors in the respective fields.

x velocity: -1.#IND
y velocity: -1.#IND
Temperature: -1.#IND

I tried varying the gauge pressure at inlet and noticed that these errors only occur when my gauge pressure goes above 4.3 bar or so. Can anyone help me understand what is going wrong here? My AMG also diverges like crazy even when I do try any values below 4bar.

my inlet flow is meant to be subsonic and transition to supersonic within the nozzle. Steam should be superheated at inlet and I wanted the analysis was meant to be looking at the formation of droplets across the turbine.

All times are GMT -4. The time now is 20:27.