I am stimulating the blood flow in the human aorta passing through the aortic valve. The computational domain is twofold: 1- aortic valve structural model (flexible), 2- flow of blood in aorta (with rigid walls). Below are the settings used to setup the project.
1- Aortic valve model in transient structural model:
· Linear elastic material with Young’s modulus of 1-2 e+06 [Pa] and Poisson’s ratio of 0.45.
· Linear/nonlinear Hex/tetrahedron elements.
· Fixed support at the base ring of the aortic valve.
· Compression only support at the inner surfaces of the aortic valve leaflets to prevent them penetrating each other.
· System Coupling Region at the surfaces of the aortic valve leaflets.
· Time step 0.005 [s]
2- Blood flow in Fluent:
· Linear Tetrahedron mesh.
· Transient, time step 0.005 [s]
· Viscous flow 0.0035 [kg/(m.s)], Density of 1060 [kg/m^3].
· One inlet pressure boundary condition, and three outlet pressure boundary conditions.
· Dynamic mesh to the fluid structure interaction surfaces: Smoothing (Spring), and Remeshing.
· System coupling, with(out) Solution Stabilization
3- System coupling
· Time step 0.005 [s], total time 0.85 [s]
· Under relaxation 1 or less
I can only get a converged solution when I am applying a high elasticity modulus (say 5-10 e 06 [Pa]), where the aortic valve movements are very small and not realistic.
I can provide more detail/photos if necessary. Please let me know.