2D Channel: Poiseuille Flow

Hi,

This post is closely related to: http://www.lbmethod.org/forum/read.php?3,2479,2508#msg-2508

I’m using the following setup:

i = inlet
o = outlet
X = WALL

XXXXXXXXXXXXXXXXXXXXXXXXXX
i ________________________o
i ________________________o
i ________________________o
i ________________________o
XXXXXXXXXXXXXXXXXXXXXXXXXX

I put a pressure boundary at inlet and outlet, the Zou/ He condition, as described in the above link.

I’m seeking a clarification, when I implement this type of method, I still have an increase in my x velocity at the outlet compared to the inlet, and some y direction velocity near the outlet both up and down.

Should the velocity not be uniform from inlet to outlet?

Does anyone else have this problem?

Thanks in advance for any advice.

Hello,

How do you implement your walls? In fact if you use incompressible Zou-He for inlet, outlet and walls boundary conditions you can obtain the velocity profiles upto the machine accuracy.

Please check whether you use BB nodes or you use the compressible boundary conditions.

Hopefully it will help,
Alex

Hi,

You should get accurate results if you use Zou He inlet, outlet (Pressure), Zou He No-Slip for walls with Incompressible model. If you use a compressible model you get an increase in velocity at outlet.

Thanks,
Narender