Moving reference frame rising bubble
 

Dear Foamers,
I am writing this post in order to ask you if someone has ever tried to implement a moving reference frame for the simulation of the rising bubble case. I am currently using openFOAM 7 and it would be very interesting, to reduce the computational cost, to simulate just a small portion of the physical domain. Do you have any suggestion on how to proceed? I was thinking of inserting some additional terms in the momentum equation in order to take into account the inertial effects, but I should also link the centroid velocity to the boundary condition far away from the bubble.

Hope to see many answers!
Best