Hello Everyone,
I’m using a D3Q19 MRT implementation on basic validation cases. In my understanding, MRT is more stable as smaller lb-viscosities, i.e. higher Re numbers. On the other hand, applying a very moderate Re number of about 200 with a high lb-velocity (e.g. v_lb~0.1) I observe stability issues, even though tau is about 0.53… Thus, I’m wondering if I misunderstood something, or if there is something wrong. I’m aware of the fact, that v_lb~0.1 is pretty close to the upper limit, but thought that MRT is more stable in such situations!? However, using half the lb-velocity, my simulation runs stable and shows pretty good results.
Please, could someone provide me with some more information or (even better) some theoretical discussion (references are welcome!),
Kind regards,
Francois