multistep Adams Bashforth schemes

suresh

Hi

I am trying to use two different time steps on different parts of the same grid (dense and coarse) to redurce the run time. I am using the adams bashforth time marching scheme to do it. It works fine but there are small errors introduced in the solution for a high frequence gust on an airfoil test case. does any body have any suggesstion about how to do this efficiently.

Thanks in advance