Plasma Discharge in Liquids: Understanding the Initiation and Formation Mechanisms of Non-Thermal Plasma in Dense Medium

该项目的重点是确定等离子体——一种自由相互作用的带电粒子和中性粒子的混合物——是如何在水或油等液体介质中形成的。液体等离子体是现代等离子体科学中最令人兴奋、最具挑战性和最重要的知识前沿之一。该项目旨在填补目前对液体中等离子体放电的理解和数学建模的空白。对等离子体放电在液体介质中开始、相互作用和维持的复杂和相互关联过程的基本机制的研究也将对等离子体科学领域以外的领域产生实质性的好处。预计将产生最大影响的独特和关键技术是生物医学-伤口愈合和灭菌，电子-纳米粒子合成，以及能源效率-液体燃料重整的高效燃烧。本项目将结合高性能计算资源，采用先进的数值方法对液体中的等离子体放电进行计算研究。本研究的主要假设是，通过复杂的电场-等离子体-液体相互作用形成低密度介质（气相）是致密（液体）介质中等离子体放电的关键起始过程。本研究将建立一个多维、多物理模型，以确定低密度区域/气泡在非极性和极性液体中等离子体放电的作用和重要性，多相介质中反应物质的产生和时空演化，以及由于耦合的质动势和欧姆加热效应而引起的相变。这项工作的主要成果预计将是在液体/致密介质中非热等离子体放电的预测建模能力方面的重大飞跃，多物理场建模的新课程材料，以增加对工程学生的教育影响，基于“YouTube”的等离子体科学入门短模块，以及鼓励代表性不足的学生和公众参与STEM的推广活动。

The focus of the project is to determine how a plasma - a mix of free interacting charged and neutral particles - is formed in liquid media such as water or oil. Plasmas in liquids is one of the most exciting, challenging and important intellectual frontiers in modern plasma science. This project is aimed towards filling in the gap in the present understanding and mathematical modeling of plasma discharges in liquids. A study of the fundamental mechanisms of complex and inter-related processes by which a plasma discharge initiates, interacts and sustains in the liquid medium will also have substantial benefits outside the field of plasma science. Unique and critical technologies envisioned to have the greatest impact are biomedical - wound healing and sterilization, electronics - nano-particle synthesis, and energy efficiency - high-efficiency combustion from liquid fuel reforming.This project will computationally investigate plasma discharges in liquids using advanced numerical methods in conjunction with high-performance computing resources. The primary hypothesis of the research is that formation of a low-density medium (gas phase) through complex electric field-plasma-liquid interactions is the key initiation process for plasma discharges in a dense (liquid) medium. A multi-dimensional, multi-physics model will be developed and employed to determine the role and importance of low-density region/bubble for plasma discharge in non-polar and polar liquids, production and spatiotemporal evolution of reactive species in a multi-phase medium, and phase change due to coupled ponderomotive forces and ohmic heating effects. The main outcomes of this effort are expected to be a major leap in the predictive modeling capability for non-thermal plasma discharges in liquid/dense medium, new course material on multi-physics modeling to increase the education impact for engineering students, "YouTube"-based introductory short modules on plasma science, and outreach activities to inspire under-represented students and the general public towards STEM.