Research / Computational methods / 03 / 06

Fluid–structure interaction

Vessels are compliant and the tissue around them moves. Treating either as rigid changes the answer; solving both directly is expensive enough to stop the study.

Deformed vessel and tissue
Coupled deformation of vessel and surrounding tissue under external compression.

Multi-fidelity coupling

We couple a one-dimensional deformable blood flow model to the three-dimensional Cauchy equation of motion for the surrounding tissue. Flow is resolved where it varies along the vessel; deformation is resolved where it varies through the tissue. Neither domain carries resolution the other does not need.

Against full three-dimensional fluid–structure interaction the scheme holds flow-rate error under one percent and pressure error under two percent, while running 9 to 46 times faster. A full pulsatile cycle takes 457 seconds on a simplified geometry and 42 minutes on a subject-specific one, which is what turns a single demonstration into a parametric study.

Wall stress without the full solve

For questions where only the solid response matters — wall stress in an aneurysm, for instance — a snapshot-based coupling estimates stress under pulsatile hemodynamics without carrying the coupled solve through every timestep.

Selected work

Under review

Efficient estimation of vessel wall stress under pulsatile hemodynamics via a snapshot-based coupling framework

Computer Methods and Programs in Biomedicine