CAREER: MULTIPHASE FLUID-MATERIAL INTERACTION: CAVITATION MODELING AND DAMAGE ASSESSMENT

Virginia Polytechnic Institute And State University, Blacksburg VA

Investigators

Abstract

Cavitation describes the formation, growth, and violent collapse of bubbles in a liquid when exposed to rapid pressure variations. If carefully controlled, cavitation can be a unique approach for high-precision material modification and fabrication, as it allows high-intensity energy pulses to be generated safely, released remotely, and focused within a small target region. The goal of this project is to understand how cavitation affects solid materials close to the bubbles; and to use this knowledge to be able to predict how cavitation modifies nearby material. The proposed research will provide new scientific insight for a broad range of engineering and biomedical applications, from fabricating materials to curing diseases. The educational and outreach component of the project will directly impact the education of K-12 schoolchildren in Central and Western Virginia, through collaboration with the Center for the Enhancement of Engineering Diversity at Virginia Tech and the Science Museum of Western Virginia in Roanoke, VA. Previous research on cavitation has primarily focused on either the fluid part of the problem, without considering the material's response, or the material part, particularly the macroscopic fracture (e.g., pits, cracks, holes) after multiple cycles of bubble collapse. This project will start with developing and experimentally validating a computational fluid dynamics/computational solid dynamics - coupled model, which will enable direct numerical simulation of up to hundreds of bubbles interacting with a broad range of materials, including fluid-induced damage and fracture. Next, the comprehensive characterization of single bubbles, tandem bubbles, and small bubble clusters collapsing near various materials will create a theoretical foundation for clarifying the micro-scale mechanisms underlying cavitation-induced material damage. Further, the direct numerical simulation model will be used to examine simplified bubbly flow models and, in combination with machine learning, design new models with improved predictive capability.