Convergence criterion for overtset grids
 

If there are two overset grids, how do you decide whether convergence is reached or not? What I did was, after interpolating from one grid to another, I check the rms of conservative variables and if for both grids they are below a tolerance (say 1e-14) then I decide convergence is reached. But the problem is that they get stuck at 1e-9. I tried both 1st and 2nd order interpolation. I use finite volume formulation.