CFD Online Discussion Forums

CFD Online Discussion Forums (https://www.cfd-online.com/Forums/)
-   FLUENT (https://www.cfd-online.com/Forums/fluent/)
-   -   Hybrid Initialization Failure (https://www.cfd-online.com/Forums/fluent/129486-hybrid-initialization-failure.html)

Persil February 6, 2014 05:55

Hybrid Initialization Failure
 
1 Attachment(s)
Hello everyone,

I simulate the flow through a turbine. There I get an error, when I try to initialize with Hybrid. It says that convergence criteria (<10e-6) could not be reached and that the pressure in some cells has reached the limit.

If I do more initialization steps, the values get even higher. When just initializing 6 steps, I don't get an error. But calculating from that point, led me to a divergence after 1400 iterations...

Checking the case, did not show problems with the mesh.

- model: energy on, realizable k-epsilon (enhanced wall treatment, viscous heating)
- material: air (ideal gas)
- boundary conditions: pressure-inlet(TI:5, TVR:10), pressure-outlet(Radial equilibrium... BTI:10,BTVR:200)... coupling via Mixing planes between each vane/blade
- solution methods: SIMPLE, Green-Gauss-Cell-Based, rest 2nd Order
- URFs: starting with 10% of default settings

what can I do to enable the initialization or where do I have to look to determine the cause for the error?

Persil February 10, 2014 10:35

Is there nobody who has an idea, why hybrid initialization failed like this? I'd really much appreciate any feedback

LiamH April 23, 2014 17:57

my experience is that when the initialization does not meet the criteria and instead goes up, that means that there is something seriously wrong with the mesh. Check your max skewness, aspect ratio and min orthogonal quality. If they are showing bad values, that is usually the problem.


All times are GMT -4. The time now is 03:39.