How do I set skewness correction in fluent?

Question

I am simulating a turbine that has curves. Mesh is structure completely. But there is high skewness in tip clearance and some parts of around of the blade:

When I use SIMPLEC Method, one factor (Skewness correction) appear under the SIMPLEC method in ANSYS Fluents method.

How I must adjust this factor? I dont know which number must be set? 1< or 1 , 2, 3?

I used K-e turbulence model and when I set Skewness correction to 5 or 20, the following error is appeared:

"Error: Divergence detected in AMG solver: k

Error: Divergence detected in AMG solver: k Error Object: #f"

Why does this happen?

Please suggest a way to reduce the skewness in ansys fluent and how can I check Skewness in Fluent?

Answer 1

First try setting skewness correction to 0, and see if Fluent produces a converged solution. If not, then you have other problems that need to be addressed first. If it converges, then increase skewness correction to 1 or 2 and retry. To address the error regarding divergence in the AMG solver, try reducing your pressure correction under-relaxation factor to less than 1.0, like 0.8 or 0.7. This will require more iterations but will be more tolerant of skewed cells.

I'm sorry I don't have any advice based on hard theory to give you. I usually just end up playing around with different settings in Fluent until I get it to work. If you have a tech support contract with ANSYS, their support staff are very knowledgeable and usually can spot problems in a Fluent model pretty quickly.

Answer 2

• firstly you have ensue that the mesh quality is good.
• try to reduce Under Relaxation Factors to values less than defaults.