Ed’s paper is accepted at J Comput Phys
Ed Terrell’s paper entitled, An Effective and Accurate Semi-Implicit Time Integration Scheme for Dynamics in Nearly- and Fully-Incompressible Hyperelastic Solids, which is co-authored by Marshall Davey and David Wells, has been accepted for publication in the Journal of Computational Physics.
This paper develops and analyzes new semi-implicit time integration schemes for simulating large dynamic deformations in nearly- and fully-incompressible hyperelastic solids. These methods are designed to avoid the severe time step restrictions imposed by fast bulk waves while remaining more efficient than fully implicit approaches. The work proves and verifies second-order accuracy, characterizes the stability of the proposed schemes, and establishes the new FEBDF2 method as an effective integrator whose time step restriction depends on the shear wave speed rather than the bulk wave speed.
Congratulations, Ed!
New NSF award on mimetic immersed boundary methods
We are thrilled to announce that we have been awarded a three-year grant through the NSF’s Computational Mathematics program to advance mimetic immersed boundary (IB) methods for fluid-structure interaction (FSI). This project focuses on IB methods that use anisotropic regularized delta functions based on composite B-splines to preserve mathematical structures that are lost by conventional IB coupling methods based on isotropic regularized delta functions. Methods resulting from the project will be implemented in IBAMR and assessed on a wide range of thin-interface and volumetric FSI benchmark cases.
Congratulations to Dr. Michael Facci!
Congratulations to Michael Facci for successfully completing his PhD and graduating in Spring 2026.
Michael’s thesis is entitled, A Robust Immersed Interface Method for Viscous Incompressible Fluids and Discrete Surfaces.
Good luck, Michael!
Josue and Laryssa’s paper is accepted at PLoS One
Josue and Laryssa’s paper, Generating patient-specific computational models with point cloud data from human atrial electrophysiology studies, has been accepted for publication in PLoS One. This paper details a large portion of Josue’s PhD thesis work, which he primarily performed under the supervision of Craig Henriquez at Duke.
Congratulations, Josue and Laryssa!
Qi’s paper is accepted at J Comput Phys
Qi Sun’s paper entitled, Improving the Robustness of the Immersed Interface Method through Regularized Velocity Reconstruction, which is co-authored by Amin Kolahdouz, has been accepted for publication in the Journal of Computational Physics.
This paper introduces a stabilization strategy for the immersed interface method that eliminates a restrictive mesh factor ratio requirement by using a Tikhonov-regularized velocity interpolation operator. The new formulation preserves accuracy while allowing the structure mesh to be much finer than the fluid grid, enabling stable and efficient simulations of complex fluid–structure interaction problems that were previously computationally prohibitive.
Congratulations, Qi!
Cole’s paper is accepted at J Comput Phys
Cole Gruninger’s paper entitled, Composite B-Spline Regularized Delta Functions for the Immersed Boundary Method: Divergence-Free Interpolation and Gradient-Preserving Force Spreading, has been accepted to appear in Journal of Computational Physics.
This paper introduces an immersed boundary method for fluid–structure interaction that employs composite B-spline regularized delta functions, which have been used previously to achieve pointwise divergence-free velocity reconstructions in computational fluid dynamics applications but not within immersed boundary formulations. The work is the first to demonstrate that these kernels preserve discrete gradient structure when spreading forces from a thin boundary to the background grid. This key conceptual advance explains their excellent volume conservation and shows that they achieve accuracy comparable to the nonlocal divergence-free immersed boundary (DFIB) method of Bao et al. while maintaining the locality and efficiency of the classical immersed boundary approach.
Congratulations, Cole!
Langtangen Prize
Our 2024 PNAS Nexus paper, Simulating cardiac fluid dynamics in the human heart, has been selected as one of two inaugural recipients of the Langtangen Prize.
The prize citation for this work is:
for the development of mathematical models of the heart that reproduce complex physiological phenomena.
The full citation for the winning paper is:
M. Davey, C. Puelz, S. Rossi, M. A. Smith, D. R. Wells, G. Sturgeon, W. P. Segars, J. P. Vavalle, C. S. Peskin, and B. E. Griffith. Simulating cardiac fluid dynamics in the human heart. PNAS Nexus, 3(10):pgae392 (16 pages), 2024.
Congratulations to Marshall, Charles, and the rest of the co-authors!
Nick Cantrell selected to UNC’s IVB program
Nick Cantrell has been selected as a trainee in UNC’s NIH-funded Integrative Vascular Biology training program.
Congratulations, Nick!
Congratulations to Dr. Cole Gruninger!
Congratulations to Cole Gruninger for successfully completing his PhD in Summer 2025.
Cole’s thesis is entitled, Advances in the Immersed Boundary Method: Viscoelastic Flows, Orthogonality-Preserving Regularization, and Robust Implicit Solvers.
Good luck, Cole!
New NIH award on cardiac modeling software infrastructure
We are thrilled to announce that we have been awarded a two-year R03 grant through the NIH’s Building Sustainable Software Tools for Open Science program to advance Cardinal, a new open-source software platform for simulating all major aspects of heart function. Cardinal will give researchers a powerful, physics-based framework for integrating clinical and experimental data to better understand disease mechanisms, test interventions, and develop personalized treatment strategies. This project will optimize Cardinal’s computational performance, improve portability across computing environments, and expand community resources—enabling more accurate, scalable, and accessible cardiac digital twin models for research and clinical translation.