{"title":"Electrospray plume divergence: Background pressure influence","authors":"","doi":"10.1016/j.jaerosci.2024.106417","DOIUrl":null,"url":null,"abstract":"<div><p>The influence of background pressure on electrospray plume evolution is observed by simulating the emission and propagation of an electrospray particle population into an electric field at a range of relevant background pressures. Differences in plume evolution from atmospheric pressure to one hundredth of atmospheric pressure are evident from plume characteristics such as (1) the overall domain of the resulting plumes and (2) the terminal angle at a downstream terminus of one standard deviation and three standard deviations of particle number density. Plume divergence and terminal angle are shown to correlate strongly with background pressure for pressures above which plume-background collision rates are significant, consistent with experimental observations of increased plume divergence with increased background pressure. The results suggest a simple expression for the pressure below which a system achieves minimum plume divergence: <span><math><mrow><msub><mrow><mi>P</mi></mrow><mrow><mi>t</mi><mi>h</mi></mrow></msub><mo>=</mo><mi>k</mi><mi>T</mi><mo>/</mo><mn>7</mn><mo>.</mo><mn>7299</mn><msub><mrow><mi>σ</mi></mrow><mrow><mi>f</mi><mi>l</mi></mrow></msub><mi>d</mi></mrow></math></span> for a system of temperature <span><math><mi>T</mi></math></span>, background fluid molecules with cross-section <span><math><msub><mrow><mi>σ</mi></mrow><mrow><mi>f</mi><mi>l</mi></mrow></msub></math></span>, and plume species of diameter <span><math><mi>d</mi></math></span>.</p></div>","PeriodicalId":14880,"journal":{"name":"Journal of Aerosol Science","volume":null,"pages":null},"PeriodicalIF":3.9000,"publicationDate":"2024-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Aerosol Science","FirstCategoryId":"93","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0021850224000843","RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENGINEERING, CHEMICAL","Score":null,"Total":0}
引用次数: 0
Abstract
The influence of background pressure on electrospray plume evolution is observed by simulating the emission and propagation of an electrospray particle population into an electric field at a range of relevant background pressures. Differences in plume evolution from atmospheric pressure to one hundredth of atmospheric pressure are evident from plume characteristics such as (1) the overall domain of the resulting plumes and (2) the terminal angle at a downstream terminus of one standard deviation and three standard deviations of particle number density. Plume divergence and terminal angle are shown to correlate strongly with background pressure for pressures above which plume-background collision rates are significant, consistent with experimental observations of increased plume divergence with increased background pressure. The results suggest a simple expression for the pressure below which a system achieves minimum plume divergence: for a system of temperature , background fluid molecules with cross-section , and plume species of diameter .
通过模拟电喷雾粒子群在一系列相关背景压力下向电场的发射和传播,观察了背景压力对电喷雾羽流演变的影响。从以下羽流特征可以明显看出从大气压到百分之一大气压的羽流演变差异:(1) 所产生羽流的总域;(2) 粒子数密度的一个标准偏差和三个标准偏差的下游终端的终端角。结果表明,当压力超过一定程度时,羽流发散和末端角度与背景压力密切相关,而当压力超过一定程度时,羽流-背景碰撞率显著增加,这与实验观察到的羽流发散随背景压力增加而增加的现象一致。结果表明了一个简单的压力表达式,在该压力以下,系统可实现最小羽流发散:对于温度为 T 的系统、横截面为 σfl 的背景流体分子和直径为 d 的羽流物种,Pth=kT/7.7299σfld。
期刊介绍:
Founded in 1970, the Journal of Aerosol Science considers itself the prime vehicle for the publication of original work as well as reviews related to fundamental and applied aerosol research, as well as aerosol instrumentation. Its content is directed at scientists working in engineering disciplines, as well as physics, chemistry, and environmental sciences.
The editors welcome submissions of papers describing recent experimental, numerical, and theoretical research related to the following topics:
1. Fundamental Aerosol Science.
2. Applied Aerosol Science.
3. Instrumentation & Measurement Methods.