Discussion Forum

I am trying to simulate a problem involving fluid flow in 2 channels separated by a porous medium. The 2D geometry consists of 3 flat domains on top of each other. The one in the middle is a porous medium whereas the other two are free channels, along which air flows (e.g. from left to right). The flow regime in the lower domain is laminar, whereas the flow regime in the upper domain is turbulent.

I have used the “free and porous media flow” module to model the flow across all domains (2 free channels and one porous medium), and the results indicate that part of the air flowing in the lower channels is, as expected, escaping through the porous medium. The problem is how to indicate in the “free and porous media flow” module that the flow in the upper domain should be turbulent, whereas the one in the lower domain is laminar. This is needed because I need to add heat transport to the model, which is dependent on the type of flow regime in question.

Initially I modelled this problem using a laminar (lower domain) and a turbulent (upper domain) flow models, “linked” by a Darcy flow module (porous medium). However, there was a problem in the boundaries of the porous medium. Since the mentioned flow models were considered in separated domains (lower and upper domains), there were unrealistic “wall” boundary conditions at the boundaries of the porous media, which resulted in having unrealistic flows near the porous domain (basically the non-slip condition imposed in the laminar side resulted in null velocity at that location).

So the question is, Is there a way to link the laminar and the turbulent flow modules using a Darcy module without having the non-slip condition at the boundary of the porous domain?

Or, if the modelling is done using the “free and porous media flow” module (for all the 3 domains), how to indicate that one of the flows is turbulent?

Thank you very much.