[faraday34]

Hello everbody

I am trying to model blood flow in arteries and struggling with errors.

First of all in fluid model only simulations there occurs negative pressures when the analysis is transient with timesteps=0.01s and total time=0.05.

When I model artery as linear elastic with characteristics of (E=2.7 MPa, Pois=0.45 and density=1120 kg/m3) FSI analysis completes the run, even the results may not be trustable.

But when I choose artery as Mooney-Rivlin the program crashes.
Solution terminates with error saying:

Fatal error occurred when requesting Total |
| Mesh Displacement for Interface.

In Ansys out file the error is:

One or more elements have become highly distorted. Excessive
distortion of elements is usually a symptom indicating the need for
corrective action elsewhere. Try ramping the load up instead of step
applying the load (KBC,1). You may need to improve your mesh to
obtain elements with better aspect ratios. Also consider the behavior
of materials, contact pairs, and/or constraint equations. If this
message appears in the first iteration of first substep, be sure to
run shape checking of elements.

Inlet blood velocity=18.2 cm/s
Outlet Pressure=0 Pa
Interface No slip
Blood density=1050 kg/m3
Blood viscosity=0.0035 Pas

BCs for the blood flow are not the exact ones in the literature. They use time varying inlet velocity and outlet pressure. I could not find any data besides graphs so if you have any excel data of these waveforms I would also appreciate if you can send to me.

Is there any idea for this error about distortion unless my BCs are so inaccurate.

I would appreciate your answers