Investigation of Thermodynamic Conditions in an Arc Discharge Plasma

电弧放电等离子体中热力学条件的研究

• 批准号: 1903481
• 负责人: Richard Miles
• 金额: $ 30万
• 依托单位: Texas A&M Engineering Experiment Station
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-07-01 至 2023-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1903481&HistoricalAwards=false
• 关键词: Investigation; Thermodynamic; Conditions; Arc; Discharge

The goal of this study is to improve our understanding of the basic physics of arc discharge plasmas. Plasma, often called the fourth state of matter, is an ionized gas that is present in almost every aspect of everyday life; and an electric arc discharge is one of the most basic plasma phenomena that are used in industry and observed in nature. Examples of electric arcs include lightning, spark plugs for combustion, plasma torches, arcjet facilities for supersonic and hypersonic flows, and devices for nanomaterials synthesis. Depending on the conditions of their generation and maintenance, arc discharge plasmas have a wide range of properties and parameters, many of which remain poorly understood. This study will be performed using both numerical simulations and state-of-the-art laser diagnostics to expand the understanding of arc discharges. Training the next generation of plasma scientists and engineers will be provided through this project while awareness about plasma technologies and its importance will be raised to local K-12 students.Despite its long history, the conditions for local thermodynamic equilibrium (LTE) in atmospheric pressure arc discharges are poorly understood due to limited experimental measurements of plasmas in thermal equilibrium. Conventional probes and optical measurements pose significant challenges since the arc core is a high temperature environment with high intensity of radiation. The focus of this project is to investigate the validity of the LTE assumption in an arc discharge operating in atmospheric pressure. Specifically, the research objectives are to: (i) develop a multidimensional nonequilibrium plasma model of a non-ablating nitrogen arc plasma coupled with a radiative heat transfer model; (ii) establish theory and analysis of the Coherent Rayleigh-Brillouin Scattering (CRBS) technique for plasma flows; and (iii) validate the computational results against experiment data, including the translational temperature obtained from CRBS and the vibrational state of nitrogen obtained from Optical Emission Spectroscopy.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

这项研究的目的是提高我们对电弧放电等离子体基本物理的理解。等离子体通常被称为物质的第四态，是一种电离气体，几乎存在于日常生活的各个方面。电弧放电是工业中使用和自然界中观察到的最基本的等离子体现象之一。电弧的例子包括闪电、燃烧用火花塞、等离子炬、用于超音速和高超音速流的电弧喷射设施以及用于纳米材料合成的装置。根据其产生和维持的条件，电弧放电等离子体具有广泛的特性和参数，其中许多特性和参数仍知之甚少。这项研究将使用数值模拟和最先进的激光诊断来进行，以扩大对电弧放电的理解。 该项目将培训下一代等离子体科学家和工程师，同时提高当地 K-12 学生对等离子体技术及其重要性的认识。尽管其历史悠久，但由于热平衡等离子体的实验测量有限，人们对大气压电弧放电中局部热力学平衡 (LTE) 的条件知之甚少。由于弧芯是具有高辐射强度的高温环境，传统探头和光学测量提出了重大挑战。该项目的重点是研究 LTE 假设在大气压下电弧放电中的有效性。具体来说，研究目标是：（i）开发与辐射传热模型相结合的非烧蚀氮弧等离子体的多维非平衡等离子体模型； (ii) 建立等离子体流相干瑞利-布里渊散射 (CRBS) 技术的理论和分析； (iii) 根据实验数据验证计算结果，包括从 CRBS 获得的平移温度和从光学发射光谱获得的氮的振动状态。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Torr-level, seedless, non-resonant velocity distribution function measurement with a dual-color, single-shot coherent Rayleigh–Brillouin scattering scheme

• DOI: 10.1088/1361-6463/acb275
• 发表时间: 2023-01
• 期刊: Journal of Physics D: Applied Physics
• 作者: J. Bak;R. Randolph;A. Gerakis