Hi,

I want to model the flow pattern in a simple U-shaped channel. The outlet of this u-shaped channel is narrowed compared to the inlet (about 30% of the inlet). In the real life process a part of the fluid (about 70%) in this channel is diffusing through a porous wall ("the third dimension"), resulting in a reduced flow rate (l/h) at the outlet of the channel. So to insure an equal flow velocity in the inlet and outlet of the channel (and throughout most of the channel), the reduction of the width of the outlet corresponds to the reduced flow rate.

Is it possible to take into account this reduction of flow rate in a 2D-model? And if so, how, and is it possible to gradually decrease the flow rate from cell to cell until the end of the channel?

Until now I have used a velocity BC on the inlet. However, since I have not been able to model the reduced flow rate at the outlet, I get an increased velocity at the outlet, due to the narrow channel.

I'm grateful for all tips you can give me!

Regards

Tom

hi,

Are you considering the porous medium effect in 2D simulation. I think if you consider the porous medium effect, then only you can get the reduced flow rate.

with regards, JSM

Thank you for the response!

I'll look into your suggestion. As the newbie I am, I suddenly discovered the world of UDF, so right now I'm thinking about writing an UDF for a source term, which might solve the problem.