FSI weird data transfer and results using Quasi-Newton method
I've been doing fluid-structure interaction simulations and I probably went through all the available documentation and tutorials offered by Ansys.
I am modeling the opening/closure of a pilot-valve. It contains three fluid domains: source (pressure inlet), drain (pressure outlet), and a pilot region which damps out the hyperelastic membrane deformation.
The fluid/solid density ratio is roughly =1, where the fluid is incompressible water and the membrane is made from a hyperelastic rubber material using the Ne-Hookean material model.
I modeled a small gap to mimic the close state of the valve. When I apply the contact detection method (contact marks with stabilization) the fluid solver diverges and crashes. So I chose a small gap size to be close to the physics.
When I tried to increase the solid density by two orders of magnitude, the solution goes smooth. However, when I switch back to the real solid density (=1100 kg/m3), I observe a force transfer increasing dramatically at each coupling iteration within a time-step and tends to infinity. I don't know where this issue comes from since I expect the IQN-LS to be able to handle the interface compatibility condition.
The figure I am attaching represents the pressure distribution within the fluid domain (See the maximum pressure).
I want to use the Quasi-newton method with an incompressible fluid.
A compressible flow with solution stabilization (coefficient-based) works fine but it is not within the scope of my research.
PS: Mesh does not have an influence on the behavior.
Thank you for your help!