pimpleFoam convergency issue
 

Hi,

I've added number of periodic source terms to momentum equations and want to verify effects of these terms on the results.
The geometry is a simple sphere with fixed boundary and the frequency of these source terms is 0.75 Hz; I used pimpleFoam solver for this purpose. I tried to lower initial residuals by restricting courant No. to 0.01 !!! but it seems that it's not enough.
Is there any suggestion concerning about other schemes or linear solvers to reduce residuals? (this case is laminar)


Thanks in advance.


Amir