Help with FSI modelling in arteries
 

Dear All,

I am trying to do two-way FSI modelling in a straight tube with an axisymmetric constriction resembling an artery model. After one iteration, an error message is given and solver exited. The error is

Fatal error occurred when requesting Total Mesh Displacement for Interface

I would like to explain my problem and would be too pleased if anybody could help me to fix this problem.

The specifications of model geometry are:
Length: 70mm
Inlet diameter: 5mm
Wall thickness:0.5mm
Minimum diameter at constricted area: 3.8mm

I went through the FSI tutorial "oscillating plate ... " and applied all steps to my case.

The material of the wall is:
Young module: 500 kpa
Poisson ratio: 0.499
Density: 1000 kg/m^3

Hex dominant (Tri/Quad) mesh method was used for both solid and fluid parts and following mesh numbers was generated.

Fluid: radial direction: 25 elements
Fluid: axial direction: 325 elements
Solid: radial direction: 12 elements
Solid: axial direction: 325 elements

The following boundary conditions were specified for solid model:

Inlet and outlet: Fixed support
Inner surface: Fluid-solid interface

The following boundary conditions were specified for fluid model:

Inlet: time dependent velocity profile with average of 3.659 mm/s
Outlet: constant static pressure 4140 pa.
Wall: fluid-solid interface

Initial conditions:
U: 0 m/s
V: 0 m/s
W:0 m/s
P: 0 m/s


Solver Control:

Fluid part:
Advection scheme: high resolution
transient scheme :second order backward
max loops: 3
convergence criteria:0.0001
Solid part:
max iteration: 10
Under relaxation factor: 0.75
Convergence target: 0.01
Thank you very much for any help you can offer.
Regards,
AshtonJ

hi ashkan
do you set large deflection on for your simulation?

Dear Sajad

I don't know how large the deflection is. artery wall material and boundary conditions used in my simulation are from previous published papers and I don't have any idea about their effect on deflection.

Thank you.
Regards