Pressure or body force for porous media

Dear Friends,

I tried to use LBGK and MRT model to simulate the permeability of 3D porous media respectively. I read some relative publications and found that most popular implementation of inlet/outlet boundary were Zou/He pressure BC, Martin Hecht pressure BC and body force instead of pressure BC. I implemented them to simulate the fluid flow in 3D porous meida obtained from X-ray CT test. The calculated premeability was much higher than the experiments when I used the former two pressure BC with bounce-back BC. When I used the body force with bounce-back BC, the average flow velocity was turned to be minus (opposite to the flow direction). It think it may be attributed to the low porosity just about 15%. It should be pointed out that I mirrior the porous media to make it really periodic.

Is there anyone have the similar experience and finding? Any suggests and comments are welcom. Thank you.



Hi Jack,

It might be a problem with BB for porous media. The good way is to use TRT/MRT models with BB, otherwise the accuracy of BB boundary depends on the relaxation parameter tau, which can influence your simulations a lot.

Hopefully it will help,

I am simulating flow of an incompressible fluid between two parallel surfaces. I am using body force driving the flow. When I see the output results, density at all the points is 1. I was wondering how can calculate dynamic pressure at different points. Velocity fields have correct value though.

I am using Palabos and my simulation is 2D.