Mike’s paper, Fluid-structure interaction models of bioprosthetic heart valves: Progress towards in vitro validation, is now available on the engrXiv. This paper uses the hyperelastic immersed boundary method to simulate the dynamics of bioprosthetic heart valves (BHVs) in models of experimental pulse duplicator systems. An initial experimental validation of the models is demonstrated through comparisons to data on pressures, flow rates, and leaflet kinematics. The paper also contrasts the flow patterns and leaflet strains and stresses generated by porcine tissue and bovine pericardial BHVs.
Congratulations to Mike Lee, who successfully completed his oral qualifying exam on fluid-structure interaction models of bioprosthetic heart valves and in vitro validation of computational models of cardiovascular fluid dynamics!
Charles’ paper, A sharp interface method for an immersed viscoelastic solid, is now available on the arXiv. This paper develops an extension of the hyperelastic immersed boundary method that sharply resolves pressure discontinuities at fluid-structure interfaces by modifying the definition of the elastic stress tensor associated with the hyperelastic material response. Unlike most other sharp-interface immersed boundary methods, however, this approach allows us to use standard discretization methods that are “oblivious” to the presence of the pressure discontinuity. Numerical tests show the impact of the method on the accuracy of the overall scheme, and an approach is developed that allows us to compute the splitting efficiently.
Amin’s paper, An immersed interface method for faceted surfaces, is now available on the arXiv. This paper develops an extension of the immersed interface method (IIM) that is specialized to faceted surfaces (arising, for instance, from finite element structural models). It also establishes through extensive numerical examples that IIMs that use only the lowest-order jump conditions (for the pressure and viscous shear stress) at immersed interfaces are able to yield global second-order convergence rates.
We expect to have one or more postdoctoral openings with start dates in 2019. For more details, see the Positions page of this site.
Ben’s paper, Stabilization approaches for the hyperelastic immersed boundary method for problems of large-deformation incompressible elasticity, is now available on the arXiv. We propose a simple stabilization that resembles approaches from nearly incompressible solid mechanics to improve the volume conservation of the immersed boundary method, as demonstrated by its performance in widely used benchmark problems of incompressible hyperelasticity adapted from the solid mechanics literature.
Congratulations to Simone Rossi for being awarded a 2019 American Heart Association Postdoctoral Fellowship!
We are trilled to announce that we just received notification of a new $160K research award on developing models of IVC filters through the NSF/FDA Scholar-in-Residence at the FDA program. This project is in collaboration with Brent Craven in the Division of Applied Mechanics in the Center for Devices and Radiological Health at the FDA.
Simone Rossi’s paper on modeling electrical impulse propagation in the atria has been accepted for publication! The citation is:
S. Rossi, S. Gaeta, B.E. Griffith, and C.S. Henriquez. Muscle Thickness and Curvature Influence Atrial Conduction Velocities. Frontiers in Physiology. Accepted for publication
In July, we welcomed two new postdoctoral researchers to the group: Saad Qadeer, who just finished his PhD in Applied Mathematics at UC-Berkeley, and David Wells, who is joining us from an RTG Postdoctoral Fellowship at RPI. Welcome to UNC!
We also said goodbye to Charles Puelz, who is starting a position as a Courant Instructor at NYU in the Fall, and to Michael Chambers, who is resuming his MD program at UNC. Good luck, Charles and Mike!