November 11, 2019: The trials and tribulations of a cavitation bubble

• November 11, 2019
• 4:00 p.m.
• 210 Robeson Hall
  
• Dr. Eric Johnsen, University of Michigan
  
• Faculty Host: Dr. Kevin Wang

Abstract: Cavitation, and the damage produced by collapsing vapor bubbles, play an important role in a variety of applications, ranging from naval hydrodynamics to ultrasound therapies. Although cavitation erosion has been the subject of extensive studies, prediction of this phenomenon remains challenging, due to its multiphysics and multiscale nature. This work examines the central problem in cavitation erosion, namely the nucleation, growth, and collapse of a single bubble. Numerical modeling and high-resolution simulations, along with collaborations with experimental colleagues, are leveraged to investigate this fundamental problem. We will discuss nuclei size distributions, energy focusing during collapse, energy release by the resulting shock waves, and potential damage to neighboring solids, including tissue-like media. Whether cavitation-induced damage is intended or not, this knowledge is important to planning safe and efficient ultrasound procedures, as well as improving the design of cavitation-resistant materials.

Bio: Eric Johnsen is an Associate Professor of Mechanical Engineering at U. Michigan. He received his BS from UCSB in 2001, and MS and PhD from Caltech in 2002 and 2008, respectively; he then spent two years as a post-doctoral fellow at the Center for Turbulence Research at Stanford
before joining U. Michigan in 2010. His research interests lie broadly in scientific computing and flow physics, including multiphase flows, turbulence, shock waves, high-energy-density physics, and high-order numerical methods. His group’s work finds applications in biomedical
engineering, energy sciences, and transportation engineering. He is a recipient of the NSF CAREER and ONR Young Investigator awards.