{"title":"Direct Numerical Simulation of Quasispherical Bubble Motion in Ultrasonic Standing Wave Fields","authors":"Hao Ni, Mingjun Pang","doi":"10.1021/acs.iecr.4c02590","DOIUrl":null,"url":null,"abstract":"To promote the development of an ultrasonic levitation technique, it is essential to understand the mechanism of bubble motion in ultrasonic standing wave fields. The trajectory of bubble motion, the levitation position, and the accompanying change in the surrounding flow field were investigated. The effects of sound pressure amplitude <i>p</i><sub><i>a</i></sub>, acoustic frequency <i>f</i>, bubble radius <i>R</i><sub>b</sub>, and gravity level <i>G/g</i> on bubble motion were fully analyzed. It was found that the bubble levitation position <i>y/λ</i> decreases with an increase in <i>p</i><sub><i>a</i></sub> but it increases with an increase in <i>R</i><sub><i>b</i></sub>, <i>f,</i> and <i>G/g</i>. The chaos of flow fields increases with an increase in <i>p</i><sub><i>a</i></sub>, <i>R<sub>b</sub>,</i> and <i>f</i>, but it decreases first and then increases with an increase in <i>G/g</i>. The time required for a bubble to remain in levitation and the flow field to be steady decreases with an increase in <i>p</i><sub><i>a</i></sub> and <i>R</i><sub><i>b</i></sub>, but it increases first and then decreases with an increase in <i>f</i> and <i>G/g</i>. Based on the equilibrium relationship between the time-averaged primary Bjerknes force <b><i>F</i><sub><i>Bj</i></sub></b> and buoyancy force <b><i>F</i><sub><i>buoy</i></sub></b>, a dimensionless parameter <i>X</i> is proposed to determine whether or not a bubble will remain in levitation, and the equation to predict bubble levitation position is presented.","PeriodicalId":39,"journal":{"name":"Industrial & Engineering Chemistry Research","volume":null,"pages":null},"PeriodicalIF":3.8000,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Industrial & Engineering Chemistry Research","FirstCategoryId":"5","ListUrlMain":"https://doi.org/10.1021/acs.iecr.4c02590","RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENGINEERING, CHEMICAL","Score":null,"Total":0}
引用次数: 0
Abstract
To promote the development of an ultrasonic levitation technique, it is essential to understand the mechanism of bubble motion in ultrasonic standing wave fields. The trajectory of bubble motion, the levitation position, and the accompanying change in the surrounding flow field were investigated. The effects of sound pressure amplitude pa, acoustic frequency f, bubble radius Rb, and gravity level G/g on bubble motion were fully analyzed. It was found that the bubble levitation position y/λ decreases with an increase in pa but it increases with an increase in Rb, f, and G/g. The chaos of flow fields increases with an increase in pa, Rb, and f, but it decreases first and then increases with an increase in G/g. The time required for a bubble to remain in levitation and the flow field to be steady decreases with an increase in pa and Rb, but it increases first and then decreases with an increase in f and G/g. Based on the equilibrium relationship between the time-averaged primary Bjerknes force FBj and buoyancy force Fbuoy, a dimensionless parameter X is proposed to determine whether or not a bubble will remain in levitation, and the equation to predict bubble levitation position is presented.
期刊介绍:
ndustrial & Engineering Chemistry, with variations in title and format, has been published since 1909 by the American Chemical Society. Industrial & Engineering Chemistry Research is a weekly publication that reports industrial and academic research in the broad fields of applied chemistry and chemical engineering with special focus on fundamentals, processes, and products.