Large-Scale Atomistic Simulations of Cavitation-Induced Plasma and Sonoluminescence - College of Engineering - Purdue University

Project Description

This project will explore the collapse of cavitation bubbles in liquids through large-scale molecular dynamics(MD) simulations. When a bubble collapses, the surrounding liquid experiences extreme, transient liquid pressures that can exceed several thousand atmospheres while gas temperatures increase tens of thousands of Kelvin. Under such conditions, strong compression leads to molecular ionization, generating a dense, short-lived plasma sometimes accompanied by a flash of light known as sonoluminescence. The atomistic origin of this plasma emission remains controversial, particularly regarding whether ionization primarily arises from undissolved gases trapped inside the bubble or from water vapor molecules at the interface. To address this, our approach is to simulate bubble collapse at the atomic level with several million water molecules surrounding a vapor cavity, allowing us to resolve the rapid compression and discrete ionization events, mapping their correlation with local pressure and temperature fields. In addition, we will study the influence of surface-active agents, a.k.a. surfactants, that can alter liquid surface tension and thus modulate collapse intensity and light emission. Such understanding has broad implications: in high-energy density physics for efficient energy focusing, in medical ultrasonics for controlling cavitation during imaging and therapy, and in nanoplasma technologies for developing compact light and radiation sources. 

Start Date

June 2026

Postdoc Qualifications

Essential Qualifications

• Ph.D. in Physics, Chemistry, Mechanical Engineering, Chemical Engineering, or related field with expertise in molecular dynamics or computational physics.
• Strong background in molecular simulation methods, including classical MD, reactive force fields (e.g., ReaxFF, COMB), or extended ensemble methods.
• Proficiency in NAMD, GROMACS, LAMMPS, or other high-performance MD packages, with experience running multi-million atom simulations. Programming/scripting skills (Python, Tcl, C++) for custom analysis is desirable.
• High-performance computing (HPC) expertise, including parallelization, scaling on supercomputers, and handling large datasets.
• Solid knowledge of fluid mechanics and cavitation physics, particularly bubble dynamics, phase transitions, and high-pressure/high-temperature processes.
• Understanding of plasma and ionization physics, or strong interest in learning, to connect MD results with plasma formation and sonoluminescence.
• Strong communication and writing skills for publishing results and preparing grant reports.

Co-advisors

• Hector Gomez (hectorgomez@purdue.edu) Mechanical Engineering  https://engineering.purdue.edu/gomez/
• Carlos Larriba-Andaluz (clarriba@purdue.edu) Mechanical Engineering Indianapolis  https://www.imospedia.com

Bibliography