prof. Annalisa Quaini's seminar at SISSA

[Emanuele Tuillier Illingworth]

SEMINAR ANNOUNCEMENT


Prof. Annalisa Quaini
(Dept. of Mathematics, University of Houston)

TITLE: Simulation of fluid-structure interaction problems arising 
hemodynamics

ABSTRACT:
We focus on the interaction of an incompressible fluid and an elastic 
structure. Two cases are considered: 1. the elastic structure covers 
part of the fluid boundary and undergoes small displacement and 2. the 
elastic structure is immersed in the fluid and it features large 
displacement.
For the first case, we propose an Arbitrary Lagrangian-Eulerian (ALE) 
method based on Lie’s operator splitting. The resulting algorithm is 
unconditionally stable and weakly coupled: it requires the solution of 
one fluid subproblem and one structure subproblem, both endowed with 
Robin type boundary conditions, per time step. This algorithm is applied 
to blood flow in a healthy straight artery and in a diseased artery with 
implanted stent.
Standard ALE methods fail when the structural displacement is large. 
Thus, for the second case we propose an extended ALE method that avoids 
remeshing.The extended ALE approach relies on a variational mesh 
optimization technique, combined with an additional constraint which is 
imposed to enforce the alignment of the structure with certain edges of 
the fluid triangulation without changing connectivity. This method is 
applied to a 2D benchmark problem modeling valves: a thin elastic 1D 
leaflet, modeled by an inextensible beam equation, is immersed in a 2D 
incompressible, viscous fluid driven by the time-dependent inlet and 
outlet data.

Venue: SISSA, lecture room 133, Wednesday 15 July at 2:30 pm