Need a paper?

Hello friends

I want to simulate two phase flow in porous media by LBM. I actually coded SC BGK D2Q9 and simulated my problem but the results weren’t satisfactory. I recently read that because of BounceBack error BGK can’t simulate very well porous media problems so we must use two relaxation time(TRT) or multirelaxation time(MRT). But i can’t use MRT because its computational price is very high besides my problem domain is very large so i consider using TRT.I think the only difference between BGK and TRT is symmetric and anti-symmetric parameters in collision operator. is this true? are there any other differences? Does anyone help me to find two relaxations time articles or share me a simple code?

Thanks a lot in advance


MRT should not be much more expensive than BGK. Some people say, the runtime is less than 10-20% larger than BGK if it is coded correctly.


Hello Timm

Thank you for your reply.

I wonder if you can send me a simple correct sample code or introduce me some good articles for coding MRT or TRT. Are there any differences between BGK and MRT or TRT except the collision operator i should make in my code?



I have never used MRT and do not have a code. But I am sure that other people here can help you with efficiency and coding related to MRT.