English  |  正體中文  |  简体中文  |  Items with full text/Total items : 70585/70585 (100%)
Visitors : 23121708      Online Users : 381
RC Version 7.0 © Powered By DSPACE, MIT. Enhanced by NTU Library IR team.
Scope Tips:
  • please add "double quotation mark" for query phrases to get precise results
  • please goto advance search for comprehansive author search
  • Adv. Search
    HomeLoginUploadHelpAboutAdminister Goto mobile version


    Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/26574


    Title: Rheology of dense bubble suspensions
    Authors: Kang,SY;Sangani,AS;Tsao,HK;Koch,DL
    Contributors: 化學工程與材料工程學系
    Keywords: LARGE REYNOLDS-NUMBERS;GAS-BUBBLES;ROTATIONAL FLOW;LIQUID;DYNAMICS;MOTION;STRESS;FORCE;PAIR;MASS
    Date: 1997
    Issue Date: 2010-06-29 17:31:26 (UTC+8)
    Publisher: 中央大學
    Abstract: The rheological behavior of rapidly sheared bubble suspensions is examined through numerical simulations and kinetic theory. The limiting case of spherical bubbles at large Reynolds number Re and small Weber number We is examined in detail. Here, Re=rho gamma alpha(2)/mu and We=rho gamma(2) alpha(3)/s, a being the bubble radius, gamma the imposed shear, s the interfacial tension, and mu and rho, respectively, the viscosity and density of the liquid. The bubbles are assumed to undergo elastic bounces when they come into contact; coalescence can be prevented in practice by addition of salt or surface-active impurities. The numerical simulations account for the interactions among bubbles which are assumed to be dominated by the potential flow of the liquid caused by the motion of the bubbles and the shear-induced collision of the bubbles. A kinetic theory based on Grad's moment method is used to predict the distribution function for the bubble velocities and the stress in the suspension. The hydrodynamic interactions are incorporated in this theory only through their influence on the virtual mass and viscous dissipation in the suspension. It is shown that this theory provides reasonable predictions for the bubble-phase pressure and viscosity determined from simulations including the detailed potential flow interactions. A striking result of this study is that the variance of the bubble velocity can become large compared with (gamma alpha)(2) in the limit of large Reynolds number. This implies that the disperse-phase pressure and viscosity associated with the fluctuating motion of the bubbles is quite significant. To determine whether this prediction is reasonable even in the presence of nonlinear drag forces induced by bubble deformation, we perform simulations in which the bubbles are subject to an empirical drag law and show that the bubble velocity variance can be as large as 15 gamma(2) alpha(2). (C) 1997 American Institute of Physics.
    Relation: PHYSICS OF FLUIDS
    Appears in Collections:[化學工程與材料工程研究所] 期刊論文

    Files in This Item:

    File Description SizeFormat
    index.html0KbHTML330View/Open


    All items in NCUIR are protected by copyright, with all rights reserved.

    社群 sharing

    ::: Copyright National Central University. | 國立中央大學圖書館版權所有 | 收藏本站 | 設為首頁 | 最佳瀏覽畫面: 1024*768 | 建站日期:8-24-2009 :::
    DSpace Software Copyright © 2002-2004  MIT &  Hewlett-Packard  /   Enhanced by   NTU Library IR team Copyright ©   - Feedback  - 隱私權政策聲明