Der All,
I’ve recently started coupling a FD heat transfer method with MRT LBM, but right now I’m struggling with the temporal coupling. Do I have to choose the FD timestep with respect to the physical timestep of the LBM?
Kind Regards,
Fred
Hi Fred.
I had the same issue not long ago. My solution to this is:
When normalizing BE to LBE, the time ( and time step as well) is normalized by L/c_rms (L is a characteristic length and c_rms is the root mean square of the speed and is equal to square(3RT/m) http://en.wikipedia.org/wiki/Root-mean-square_speed).
So, the real dt is equal to L/c_rms.
Best regards.
Tal