{"title":"不同重力水平下低频振动对单个气泡水动力特性的影响","authors":"Hao Ni, MingJun Pang","doi":"10.1007/s12217-023-10073-w","DOIUrl":null,"url":null,"abstract":"<div><p>A key aspect of space application technology is the generation and control of multi–phase flows. The efficiency of mass and heat transfer can be significantly improved by adding bubbles or droplets into continuous phases. The effects of the ratio of amplitude to bubble diameter (<i>A/D</i>), Bond number (<i>Bo</i>), and different gravity levels (<i>G/g</i>) on bubble centroid motion and shape oscillation are fully analyzed using the VOF method to understand the bubble–centroid trajectory and shape–oscillation mechanism under low–frequency vibrations. The present studies show that <i>A/D</i>, <i>Bo</i>, and <i>G/g</i> have important effects on bubble trajectory and shape oscillation. There are two types of oscillations for bubble shape: regular oscillation and chaotic oscillation. As <i>Bo</i> and <i>A/D</i> increase, bubble oscillation in a gravity–free environment changes from regular to chaotic oscillation. For the present results, bubble oscillations at different gravity levels (except zero–gravity level) are chaotic oscillations. Three types are recognized for the bubble–centroid motion: levitation, rising and sinking. When both <i>A/D</i> and <i>Bo</i> are tiny, a bubble is hung in its initial position in a gravity–free environment. Bubble–centroid motion changes from sinking to rising with an increase in <i>A/D</i> and <i>Bo</i>. The higher the gravity level is, the shorter the time taken for the bubble to rise is. The change in the flow field seems to be mainly caused by the vibration of fluid particles, almost independent of the level of gravity. The flow field becomes more chaotic as <i>A/D</i> and <i>Bo</i> increase.</p></div>","PeriodicalId":707,"journal":{"name":"Microgravity Science and Technology","volume":"35 5","pages":""},"PeriodicalIF":1.3000,"publicationDate":"2023-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Effect of Low–Frequency Vibrations on the Hydrodynamic Properties of Single Bubbles at Different Gravity Levels\",\"authors\":\"Hao Ni, MingJun Pang\",\"doi\":\"10.1007/s12217-023-10073-w\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>A key aspect of space application technology is the generation and control of multi–phase flows. The efficiency of mass and heat transfer can be significantly improved by adding bubbles or droplets into continuous phases. The effects of the ratio of amplitude to bubble diameter (<i>A/D</i>), Bond number (<i>Bo</i>), and different gravity levels (<i>G/g</i>) on bubble centroid motion and shape oscillation are fully analyzed using the VOF method to understand the bubble–centroid trajectory and shape–oscillation mechanism under low–frequency vibrations. The present studies show that <i>A/D</i>, <i>Bo</i>, and <i>G/g</i> have important effects on bubble trajectory and shape oscillation. There are two types of oscillations for bubble shape: regular oscillation and chaotic oscillation. As <i>Bo</i> and <i>A/D</i> increase, bubble oscillation in a gravity–free environment changes from regular to chaotic oscillation. For the present results, bubble oscillations at different gravity levels (except zero–gravity level) are chaotic oscillations. Three types are recognized for the bubble–centroid motion: levitation, rising and sinking. When both <i>A/D</i> and <i>Bo</i> are tiny, a bubble is hung in its initial position in a gravity–free environment. Bubble–centroid motion changes from sinking to rising with an increase in <i>A/D</i> and <i>Bo</i>. The higher the gravity level is, the shorter the time taken for the bubble to rise is. The change in the flow field seems to be mainly caused by the vibration of fluid particles, almost independent of the level of gravity. The flow field becomes more chaotic as <i>A/D</i> and <i>Bo</i> increase.</p></div>\",\"PeriodicalId\":707,\"journal\":{\"name\":\"Microgravity Science and Technology\",\"volume\":\"35 5\",\"pages\":\"\"},\"PeriodicalIF\":1.3000,\"publicationDate\":\"2023-09-05\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Microgravity Science and Technology\",\"FirstCategoryId\":\"5\",\"ListUrlMain\":\"https://link.springer.com/article/10.1007/s12217-023-10073-w\",\"RegionNum\":4,\"RegionCategory\":\"工程技术\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"ENGINEERING, AEROSPACE\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Microgravity Science and Technology","FirstCategoryId":"5","ListUrlMain":"https://link.springer.com/article/10.1007/s12217-023-10073-w","RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENGINEERING, AEROSPACE","Score":null,"Total":0}
Effect of Low–Frequency Vibrations on the Hydrodynamic Properties of Single Bubbles at Different Gravity Levels
A key aspect of space application technology is the generation and control of multi–phase flows. The efficiency of mass and heat transfer can be significantly improved by adding bubbles or droplets into continuous phases. The effects of the ratio of amplitude to bubble diameter (A/D), Bond number (Bo), and different gravity levels (G/g) on bubble centroid motion and shape oscillation are fully analyzed using the VOF method to understand the bubble–centroid trajectory and shape–oscillation mechanism under low–frequency vibrations. The present studies show that A/D, Bo, and G/g have important effects on bubble trajectory and shape oscillation. There are two types of oscillations for bubble shape: regular oscillation and chaotic oscillation. As Bo and A/D increase, bubble oscillation in a gravity–free environment changes from regular to chaotic oscillation. For the present results, bubble oscillations at different gravity levels (except zero–gravity level) are chaotic oscillations. Three types are recognized for the bubble–centroid motion: levitation, rising and sinking. When both A/D and Bo are tiny, a bubble is hung in its initial position in a gravity–free environment. Bubble–centroid motion changes from sinking to rising with an increase in A/D and Bo. The higher the gravity level is, the shorter the time taken for the bubble to rise is. The change in the flow field seems to be mainly caused by the vibration of fluid particles, almost independent of the level of gravity. The flow field becomes more chaotic as A/D and Bo increase.
期刊介绍:
Microgravity Science and Technology – An International Journal for Microgravity and Space Exploration Related Research is a is a peer-reviewed scientific journal concerned with all topics, experimental as well as theoretical, related to research carried out under conditions of altered gravity.
Microgravity Science and Technology publishes papers dealing with studies performed on and prepared for platforms that provide real microgravity conditions (such as drop towers, parabolic flights, sounding rockets, reentry capsules and orbiting platforms), and on ground-based facilities aiming to simulate microgravity conditions on earth (such as levitrons, clinostats, random positioning machines, bed rest facilities, and micro-scale or neutral buoyancy facilities) or providing artificial gravity conditions (such as centrifuges).
Data from preparatory tests, hardware and instrumentation developments, lessons learnt as well as theoretical gravity-related considerations are welcome. Included science disciplines with gravity-related topics are:
− materials science
− fluid mechanics
− process engineering
− physics
− chemistry
− heat and mass transfer
− gravitational biology
− radiation biology
− exobiology and astrobiology
− human physiology