something about the Periodic boundary condition in fluent
 

Hello
I have a problem about using the Periodic .

I am going to make a model like the picture , flow over a plate ,and make some groove to reduce the drag, the boundary condition is that velocity inlet .out flow

flow direction is x the direction z is periodic condition . the problem is that same size of the v groove in the two picture. but when i got the results,the wall-shear stress on the V groove is obviously different
I WANT to know that:
1can this periodic stimulate the cast that flow over a plate with groove？
2.and what make the difference between the two case？

Attachment 62659

Attachment 62660

Attachment 62661

You should get the same result.

Try tinkering with the mesh. It looks like you have skewed cells and high aspect ratio cells everywhere. I'm surprised it didn't blow up in your face.

Thanks for your reply

I find that i had made the quality about the aspect ratio is bad.
this problem is just because of high aspect ratio？ or maybe other reason？

now i am going to set more nodes along the X direction

thanks