Hello everyone,

I'm a rookie in the CFD simulations, therefore, perhaps my question could be a little stupid... but anyway I have to ask because I have a great headache for its guilty. I am trying to simulate the steady flow conditions in a complex geometry compartment by CFD. The liquid studied is water and I am running a commercial package (Femlab).

In order to start the simulation of the system with an accurate approximation of velocity and pressure profile values I have started simulating the system with high values of viscosity and after I have decreased them, but, when I have arrived near a value of 0.0035 for the viscosity of the water I find that the system doesn't converge and I don't get any accurate value. I have test several options like iterative methods, adaptive methods, and I have also tried to increase the mesh near the boundaries of my geometry, but it doesn't work.

Could someone help me? Thank you in advance

PD: Excuse my poor English. Thank you again.

reduce viscosity = increase Re number, It is well known when Re is high, flow instability occurs, which makes steady-state convergence impossible.