[CFXer]

Hello.

I'm trying to do flow simulation in counter flow structure.

It's velocity is so fast, so this flow is turbulent flow, using k-e turbulence model.

Initially, the streamline shows colliding flow in inlet structure, as you can see in Fig.1, but it makes vortex at the center when it is completely converged.

I have two question for this.

1. Is this streamline correct? some people say the flow should be collided at the center of the structure, but some people say the vortex flow is correct. I cannot find any previous research about this phenomena.

2. To validate whether this result is correct, I checked the Turbulence Kinetic Energy(TKE) at inlet structure. I think this vortex flow is shown in laminar flow, but when the flow is in turbulent area, turbulent dissipation could make the flow random shape, not only vortex shape.

So I want to check the TKE at this simulation, whether it is large enough to consider turbulence.

But I don't have criteria to judge whether the TKE value is large enough. Does anyone have any idea to judge how the TKE value is large enough? How can I determine the criteria?

Thank you in advance.