{"title":"Numerical study on effects of granular deformations on dense powder conveying using a modified two-fluid model","authors":"Shilin Gao, Zaiyin Ma, Haibin Zhang, Bofeng Bai","doi":"10.1016/j.powtec.2025.121357","DOIUrl":null,"url":null,"abstract":"<div><div>Granular deformations exert significant effects on conveying dynamics, coupled with inherent multiscale nonlinearity and complex rheological characteristics of dense powder flows, necessitating further in-depth investigations to unveil dense powder conveying mechanisms. Based on the coupling of the multiple-state theory, granular deformations have been introduced into the modified two-fluid model (TFM) through the refinement of the mesoscopic solid-pressure model in this study. To validate the modified TFM, a dense powder conveying experiment featuring a built-in fluidization gas intake structure was conducted, in which the instability of startup behaviors, directly affecting the optimization of conveying strategies, have been preliminarily identified. Moreover, a comparative analysis with multiple experimental results demonstrates the accuracy and reliability of the developed numerical model, highlighting the necessity of accounting for granular deformations. Using the modified TFM, the startup behaviors of dense powder conveying were thoroughly analyzed, revealing effects of granular deformations on increasing peak powder flow rates and the solid-gas ratio, indicating the non-ideal linearity of powder flow rate and fluidization pressure, and illustrating the decompression process within the powder layer. Additionally, inhomogeneous local solid-pressure concentrations within the powder flow resulting from the internal structures and fluidizing gas, and their impacts on conveying dynamics were captured in the simulations. The findings could provide valuable insights into the details of dense powder conveying and present a novel numerical approach, contributing significantly to the design and optimization of granular systems.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"465 ","pages":"Article 121357"},"PeriodicalIF":4.6000,"publicationDate":"2025-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Powder Technology","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0032591025007521","RegionNum":2,"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
Granular deformations exert significant effects on conveying dynamics, coupled with inherent multiscale nonlinearity and complex rheological characteristics of dense powder flows, necessitating further in-depth investigations to unveil dense powder conveying mechanisms. Based on the coupling of the multiple-state theory, granular deformations have been introduced into the modified two-fluid model (TFM) through the refinement of the mesoscopic solid-pressure model in this study. To validate the modified TFM, a dense powder conveying experiment featuring a built-in fluidization gas intake structure was conducted, in which the instability of startup behaviors, directly affecting the optimization of conveying strategies, have been preliminarily identified. Moreover, a comparative analysis with multiple experimental results demonstrates the accuracy and reliability of the developed numerical model, highlighting the necessity of accounting for granular deformations. Using the modified TFM, the startup behaviors of dense powder conveying were thoroughly analyzed, revealing effects of granular deformations on increasing peak powder flow rates and the solid-gas ratio, indicating the non-ideal linearity of powder flow rate and fluidization pressure, and illustrating the decompression process within the powder layer. Additionally, inhomogeneous local solid-pressure concentrations within the powder flow resulting from the internal structures and fluidizing gas, and their impacts on conveying dynamics were captured in the simulations. The findings could provide valuable insights into the details of dense powder conveying and present a novel numerical approach, contributing significantly to the design and optimization of granular systems.
期刊介绍:
Powder Technology is an International Journal on the Science and Technology of Wet and Dry Particulate Systems. Powder Technology publishes papers on all aspects of the formation of particles and their characterisation and on the study of systems containing particulate solids. No limitation is imposed on the size of the particles, which may range from nanometre scale, as in pigments or aerosols, to that of mined or quarried materials. The following list of topics is not intended to be comprehensive, but rather to indicate typical subjects which fall within the scope of the journal's interests:
Formation and synthesis of particles by precipitation and other methods.
Modification of particles by agglomeration, coating, comminution and attrition.
Characterisation of the size, shape, surface area, pore structure and strength of particles and agglomerates (including the origins and effects of inter particle forces).
Packing, failure, flow and permeability of assemblies of particles.
Particle-particle interactions and suspension rheology.
Handling and processing operations such as slurry flow, fluidization, pneumatic conveying.
Interactions between particles and their environment, including delivery of particulate products to the body.
Applications of particle technology in production of pharmaceuticals, chemicals, foods, pigments, structural, and functional materials and in environmental and energy related matters.
For materials-oriented contributions we are looking for articles revealing the effect of particle/powder characteristics (size, morphology and composition, in that order) on material performance or functionality and, ideally, comparison to any industrial standard.