WSS lack of convergence

longchuan

Hi, FLuent experts

I am simulating the influence of the presence of a needle turbulence in a tube on the tube flow downstream. When I was checking the WSS along the wall downstream. I find that in the distance (cm) vs. WSS plot, the WSS profile has zigzag shape (vibrating with a magnitude of 0.1 Pascal). Someone told me that this is a sign of either lack of convergence or unsufficient mesh size. However, I think the convergence should not be a problem here and my mesh size is around 6 million for the model.

I would really appreciate if someone could give me some insights on this.

Thank you