My project involves mass transport through convection and diffusion + free flow in pipe + flow in porous media. I know in 'reacting flow in porous media' we can couple mass transport too while 'free and porous media' module can not. I have attached my model picture where in the bottom rectangular region I have my porous media and on the top region free fluid flow is happening.
I tried to simulate the same model keeping all the propertiessame, in both the above mentioned module. However, I am having lot of dissimilarities. I have attached the results from both the modules. In the reacting flow porous media module I see fluid is having non zero velocity in the central region in porous media domain, also fluid from the top is travelling inside the porous media domain smoothly.
However, in the free and porous media flow, I see almost zero velocity everywhere in the porous media domain.
If both the modules are solving brinkman's equation in porous media and NS equation in free flow region then how come the flow patterns are different? your guidance will be highly appreciated. Thanks in advance!