Learning Forum

[ggege0524]

​I want to apply periodic boundary conditions, but I have some trouble with it. 

​I am simulating the mixing of two different gases, supersonic, and I have the geometry that you can see below. One of them is injected axially and the other radially. This is only a section of my geometry. I want to have a repeating flow, so to use periodic boundary conditions. The whole angle of this section is 10 degree. 

I proceeded as follows:

 Firstly, I applied match twice control, one time for opposite sides facing each other of the small cube and the same for the bigger part. It worked except for a warning: "one or more nodes of the vertices on the lower side of a matched mesh control were moved further than the tolerance"

Then I defined the faces as interface and the latter as periodic. You can see a figure of these those seating below. 

But when tried to initiate the simulation, I got an error, shown below. 

Could somebody please help me solve this problem?

Ps: A few details about the simulation: pressure-based, compressible, supersonic, turbulent, energy on, species on, mixing, no reaction, no combustion, steady, pressure inlets, pressure outlet.  

 

[Rob]

Have a look at the rotation axis definition. 

[ggege0524]

Sorry, but I still don't get it. I don't know, what's wrong with it. The part is rotated around z-Direction, so I guess the origine is wrong, but I have no idea why.

[Rob]

It looks like the axis is along x in your image. 

[ggege0524]

I don't think, that is the problem. I tried all the three axis and none of them works. I still get this  warning  : "

Warning: Non-intersected faces found for the matching interface periodic_pr1_pr3! Please improve the alignment of interface zones!"

and this error:  "Error: Non-conformal periodic interface periodic_pr2_pr4 with empty intersection.

This is likely due to incorrect specification of periodic

offset values. Please check the offset values specified

and recreate the interface.

 

Error: Non-conformal periodic interface periodic_pr1_pr3 with empty intersection.

This is likely due to incorrect specification of periodic

offset values. Please check the offset values specified

and recreate the interface." , when I try to initiliaze the solution.

[Rob]

Check the surface pairs, axis and angle. This is needed before trying to initialise the model.