Learning Forum

[zahlenritter]

Dear community,

I am trying to simulate an axial compressor with a circumferential groove, but the interface 
between main flow path and groove is not working as expected and just generates a solid wall there.

To simulate the influence of circumferential grooves I am given a mesh of an axial compressor.
In a CAD-Software I construct my groove, which I importat and mesh in ICEM. Finally I load the 
mesh as a .cfx5-file into my case. I create a domain interface between compressor shroud and the groove
side, pointing towards the shroud. For non-overlapping part at the compressor I apply a no slip wall as a a nonoverlap
Condition. 

 

During postprocessing I noticed that the interface between both meshes is treated as a wall and not an interface with momentum exchange.
I suspect that small geometric differences which are not visible, cause the meshes to not exactly match in the radial direction. As a result
the no slip conditions is applied at the whole shroud.

But how do I fix this problem?

Best regards

 

 

 

[CFD_Friend]

Hi,

The reason is that the distance between the interface faces is above the tolerance level. You have to keep both of them very close to achieve a proper connection. Otherwise, it creates a non-overlap condition. Try to make this as close as possible to avoid such problems.

You can check whether the interfaces are in non-overlap condition or not, using contours in CFD-Post. Select the shroud boundary, and create a contour using the variable "Nonoverlap Fraction"

If the boundaries overlap, that section will be colored blue (value =  0), if there is no overlap, then that region will be colored red (value =1)