Granular temperature in a gas fluidized bed

Mark J. Biggs*, Don Glass, Liansong Xie, Vladimir Zivkovic, Alex Buts, M. A. Curt Kounders

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

28 Citations (Scopus)


The mean square of particle velocity fluctuations, δ v 2, which is directly related to the so-called granular temperature, plays an important role in the flow, mixing, segregation and attrition phenomena of particulate systems and associated theories. It is, therefore, important to be able to measure this quantity. We report here in detail our use of diffusing wave spectroscopy (DWS) to measure the mean square particle velocity fluctuations for a 2D non-circulating gas fluidized bed of hollow glass particles whose mean diameter and effective density are 60 μm and 200 kg/m 3, respectively. Mean square particle velocity fluctuations were observed to increase with superficial velocity, U s, beyond the minimum fluidization velocity. Following the uniform fluidization theory of Batchelor (1988), the function f(φ ) in the expression δ v 2 = f(φ)U s 2 was also determined and shown to increase from zero at a solids loading of φ ≈ 0.33 to a maximum at φ ≈ 0.4 before decreasing again to zero at φ ≈ 0.53. The spatial variation of the mean square particle velocity fluctuations was also determined and shown to be approximately symmetrical about the centreline where it is also maximal, and to increase with height above the distributor.

Original languageEnglish
Pages (from-to)63-73
Number of pages11
JournalGranular Matter
Issue number2
Publication statusPublished - Jan 2008


  • Diffusing wave spectroscopy
  • Erosion
  • Fluidized bed
  • Granular temperature
  • Granulation
  • Heat transfer
  • Kinetic theory
  • Velocity fluctuations

ASJC Scopus subject areas

  • General Materials Science
  • Mechanics of Materials
  • General Physics and Astronomy


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