Mechanical Engineering Graduate Seminar Series: Dr. Mauro Rodriguez Jr, Brown University, "A Eulerian Multi-Component Framework for Fluid-Structure Interaction Problems Involving Cavitation"

Abstract: The manipulation of cavitating, bubbly flows is a critical need across a wide range of applications including naval hydraulic, energy science, and biomedicine. Cavitation is a pressure-driven vaporization process that can take place in highly transient liquid flows. In naval hydraulic applications, cavitation erosion of propeller blades is undesired. The erosion inhibits performance and is the primary source of frequent, costly maintenance. To address this adverse effect and biofouling, viscoelastic coatings are applied to the blades. Nevertheless, cavitation erodes these coatings, which then also needs costly reapplication. Similarly, cavitation erosion limits the operation life cycle and performance of the Department of Energy's Spallation Neutron Source experiments used to develop a wide range of technologies. On the other hand, cavitation is desired in biomedicine. An example is non-invasive, focused ultrasound therapy tools. These tools generate cavitation bubbles to erode kidney and gallbladder stones (lithotripsy) or ablate soft, pathogenic tissues (histotripsy). Understanding the bubble dynamics and material response interactions is needed to increase the efficacy of these tools.

To study these fluid-structure interaction problems, the challenge is to numerically simulate small bubbles in a bubble cloud with wave dynamics in the fluid(s) and nearby solid. Unlike the gas bubbles and surrounding liquid that lend themselves to a Eulerian framework, the nearby solid undergoes infinitely small to finite deformations that are well-suited to be captured in a Lagrangian framework. However, algorithmic complexity increases significantly with two separate solvers and coupling between them. During the seminar, a Eulerian numerical framework with an elasticity model to solve multi-component fluid-structure interaction problems including multi-scale cavitation will be presented. Physical insights involving two canonical flows, i.e., shock-induced collapse of a bubble near an elastic object and a confined bubble in a channel, will be detailed. Future directions and applications for numerically simulating multi-component flows involving extreme deformations in and near viscoelastic materials will also be presented.

Bio: Mauro Rodriguez Jr.is an Assistant Professor of Engineering in the School of Engineering at Brown University, where he joined the faculty in 2021.In 2010, Rodriguez earned his B.S. degree with honors in Mechanical Science and Engineering from the University of Illinois at Urbana-Champaign (UIUC). In2012, he received an M.S. in Mechanical Engineering from Stanford University as a graduate engineering fellow. He earned with Ph.D. in Mechanical Engineering from the University of Michigan, Ann Arbor under the supervision of Associate Professor Eric Johnsen. Rodriguez's doctoral thesis focused on high-fidelity computational fluid dynamic simulations of bubble dynamics near (linear) viscoelastic media. Prior to joining Brown, Rodriguez was a Ford Foundation and National Science Foundation-Alliances for Graduate Education and the Professoriate postdoctoral research fellow at the California Institute of Technology under the mentorship of Professor Tim Colonius. Rodriguez’s current research interests are in cavitation bubble dynamics in and near viscoelastic materials. He uses high-fidelity computational fluid dynamics to study wave and bubble dynamics in and near hard/soft materials relevant to energy science, naval engineering, and biomedicine applications. A Chicago Little Village native, Rodriguez is passionately committed to increasing underserved and underrepresented individuals, diversity, equity, and inclusion across all levels of science, technology, engineering, and math (STEM) workforce pathways.