I am doing 2 way FSI simulation of a flap.Case is 3D and flow is laminar .I started simulation with pressure based transient flow using time step 1e-4. Coupled scheme is used with second order implicit transient formulation.
Case worked well until 1800 coupling steps then suddenly I got the error
"Divergence detected in AMG solver, pressure coupling"
I want to know the reason for this type of error, if any one could guide me please. Is there any problem in solver or discretization scheme?
Waiting for a kind response.