Perfecting Simulations and Recipes - Profile Joar Bagge: O'Donnell Postdoc

“I’ve been getting into bouldering since living in Austin,” said Joar Bagge, a Peter O’Donnell, Jr. Postdoctoral Fellow at the Oden Institute of Computational Engineering and Sciences. While a mild fear of heights cautions him against getting too far from the safety of solid ground, Bagge chases new ways to challenge himself, both professionally and personally. 

Bagge joined the Oden Institute at The University of Texas at Austin in 2024, after obtaining his Ph.D. in Applied and Computational Mathematics from KTH Royal Institute of Technology in Stockholm. Now, he works within the Center for Numerical Analysis and the Parallel Algorithms for Data Analysis and Simulations Group under George Biros and Per-Gunnar Martinson to develop numerical methods for performing simulations on problems related to Stokes flow. 

After spending years growing up on Sweden’s glittering coastline, Bagge’s work now focuses on fluids at a much smaller scale. The Stokes model gives us insight into the dynamics of how microorganisms swim, or how microfluidic devices can be used in biomedical contexts. “I work specifically on modeling capsules,” shared Bagge, “which act as a model for red blood cells in our bodies.” This enhances our understanding of how blood cells tend to move in the body within the geometry of our blood vessels, and lays the foundation for biomedical experimentation on these cells, with potential to use them as a device or carrier within the body."

Creating models that run accurately, quickly, and efficiently serves as the underlying thesis of Bagge’s research. “Boundary integrals formulated from partial differential equations that describe Stokes flow allow us to discretize the surface of the capsule, instead of modeling its entire volume,” Bagge described. While maintaining the accuracy of the simulation, this allows researchers to save computational time and energy. 

The human body contains upwards of 20-trillion red blood cells, coursing through our veins and arteries. Modeling the interactions they have with each other also becomes critical in order to create a representative model. “My research uses fast summation methods to compute these interactions efficiently,” shared Bagge.

This translates into writing software that runs using supercomputers at the Texas Advanced Computing Center (TACC). Bagge’s work in optimizing the efficiency of these simulations makes it possible to run a wide variety of simulations using different permutations of varying physical parameters, in order to see how they affect the motion of the red blood cell capsule. “One of my favorite parts of my work is making beautiful colorful figures and animated movies that illustrate my results,” Bagge said. “Adding creativity into science brings me a lot of happiness.”
 

Creativity forms the cornerstone for many of Bagge's passions beyond the lab, many of which have supported him through his move to life in Austin. He often immerses himself in his love for cooking, a passion he’s held since moving away from home at age 16 to pursue his education. Traditional Swedish cooking often gives him the taste of home he craves, as he navigates living an ocean apart from his wife and cat, Muffe. “I love exploring food from around the world as well,” he added. In addition to cooking, Bagge has a passion for playing the piano, finding joy in music as another way to unwind and creatively express himself. 

In combining a passion for research with a sense of creative expression as he explores life in Austin, Bagge exemplifies the benefits of chasing challenges with balance. 

O'Donnell Fellows perform interdisciplinary research with exceptional faculty in areas such as computational mechanics and computational oncology, among many others. They also have the opportunity to participate in external collaborations and access world-class computational tools including the fastest supercomputer on a university campus. Applications are accepted September – December and can be accessed here.