Convergence issues with long period sloshing flows
 

Does anyone know any tricks to get my solution to converge for a long period (~15 secs) sloshing flow? The excitation of the domain is just some A * sin (2*Pi/T * time). If my period is long then the solution (moment time history) doesn't look smooth. If I shorten it then things look great and match theory. Any suggestions?

Re: Convergence issues with long period sloshing f
 

By period do you mean the flow time? In this case the moment time history couldn't look smooth because of non-linear effects due to the interaction between the frequency 1/T of your excitation and the natural frequency of the fluid in the tank. As long as your solution converges well (preferably within 10 or less iterations) every time step, I never found unrealistic results...

Hope this helps

Edi.