{"title":"不同流型筒仓中粉末流动和壁面法向应力的动态演变","authors":"Minghao You, Xin Wang, Yifu Shi, Bing Luo, Cai Liang, Daoyin Liu, Jiliang Ma, Xiaoping Chen","doi":"10.1016/j.ijmultiphaseflow.2024.104844","DOIUrl":null,"url":null,"abstract":"<div><p>Major safety accidents involving silos in industrial processes are closely associated with abnormal wall stresses. The effects of different flow patterns and particle velocity distribution on wall stresses are investigated during silo discharge. The existence of particle velocity retardation layer near the wall boundary in the mass flow was observed by tracer particles and high-speed camera. The silo discharge undergoes a transformation from funnel flow to mass flow at a hopper half angle of 30°. As the outlet diameter increases, the time point of the flow pattern transformation becomes more and more later. The evolution of particle velocity in the central of the funnel flow is related to the outlet velocity wave propagation and the V-shaped surface expansion. The relationship between stress fluctuations and velocity characteristics is established. The flow channel simultaneously expands upwards as the velocity wave propagates and generates a periodic fan-shaped velocity wave at the top. The formation of stress concentration zone at the bin/hopper transition was observed.</p></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":null,"pages":null},"PeriodicalIF":3.6000,"publicationDate":"2024-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"The dynamic evolution of powder flow and wall normal stress in different flow pattern silos\",\"authors\":\"Minghao You, Xin Wang, Yifu Shi, Bing Luo, Cai Liang, Daoyin Liu, Jiliang Ma, Xiaoping Chen\",\"doi\":\"10.1016/j.ijmultiphaseflow.2024.104844\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>Major safety accidents involving silos in industrial processes are closely associated with abnormal wall stresses. The effects of different flow patterns and particle velocity distribution on wall stresses are investigated during silo discharge. The existence of particle velocity retardation layer near the wall boundary in the mass flow was observed by tracer particles and high-speed camera. The silo discharge undergoes a transformation from funnel flow to mass flow at a hopper half angle of 30°. As the outlet diameter increases, the time point of the flow pattern transformation becomes more and more later. The evolution of particle velocity in the central of the funnel flow is related to the outlet velocity wave propagation and the V-shaped surface expansion. The relationship between stress fluctuations and velocity characteristics is established. The flow channel simultaneously expands upwards as the velocity wave propagates and generates a periodic fan-shaped velocity wave at the top. The formation of stress concentration zone at the bin/hopper transition was observed.</p></div>\",\"PeriodicalId\":339,\"journal\":{\"name\":\"International Journal of Multiphase Flow\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":3.6000,\"publicationDate\":\"2024-04-20\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"International Journal of Multiphase Flow\",\"FirstCategoryId\":\"5\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0301932224001228\",\"RegionNum\":2,\"RegionCategory\":\"工程技术\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"MECHANICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"International Journal of Multiphase Flow","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0301932224001228","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MECHANICS","Score":null,"Total":0}
引用次数: 0
摘要
工业流程中涉及筒仓的重大安全事故与异常壁应力密切相关。研究了筒仓卸料过程中不同流动模式和颗粒速度分布对壁应力的影响。通过示踪粒子和高速照相机观察到在质量流中靠近壁面边界的粒子速度迟滞层的存在。在料斗半角为 30° 时,料仓卸料经历了从漏斗流到质量流的转变。随着出口直径的增大,流型转变的时间点越来越晚。漏斗流中心颗粒速度的演变与出口速度波的传播和 V 形表面扩张有关。建立了应力波动与速度特征之间的关系。随着速度波的传播,流道同时向上扩展,并在顶部产生周期性的扇形速度波。观察到在料仓/料斗过渡处形成了应力集中区。
The dynamic evolution of powder flow and wall normal stress in different flow pattern silos
Major safety accidents involving silos in industrial processes are closely associated with abnormal wall stresses. The effects of different flow patterns and particle velocity distribution on wall stresses are investigated during silo discharge. The existence of particle velocity retardation layer near the wall boundary in the mass flow was observed by tracer particles and high-speed camera. The silo discharge undergoes a transformation from funnel flow to mass flow at a hopper half angle of 30°. As the outlet diameter increases, the time point of the flow pattern transformation becomes more and more later. The evolution of particle velocity in the central of the funnel flow is related to the outlet velocity wave propagation and the V-shaped surface expansion. The relationship between stress fluctuations and velocity characteristics is established. The flow channel simultaneously expands upwards as the velocity wave propagates and generates a periodic fan-shaped velocity wave at the top. The formation of stress concentration zone at the bin/hopper transition was observed.
期刊介绍:
The International Journal of Multiphase Flow publishes analytical, numerical and experimental articles of lasting interest. The scope of the journal includes all aspects of mass, momentum and energy exchange phenomena among different phases such as occur in disperse flows, gas–liquid and liquid–liquid flows, flows in porous media, boiling, granular flows and others.
The journal publishes full papers, brief communications and conference announcements.