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Title: Statistics of velocity fluctuations of Geldart A particles in a circulating fluidized bed riser

Journal Article · · Physical Review Fluids
 [1];  [2];  [3]
  1. National Energy Technology Lab. (NETL), Morgantown, WV (United States); Oak Ridge Inst. for Science and Education (ORISE), Oak Ridge, TN (United States)
  2. National Energy Technology Lab. (NETL), Morgantown, WV (United States)
  3. National Energy Technology Lab. (NETL), Morgantown, WV (United States); West Virginia Univ., Morgantown, WV (United States). Research Corp.
+ Show Author Affiliations

Here, the statistics of fluctuating velocity components are studied in the riser of a closed-loop circulating fluidized bed with fluid catalytic cracking catalyst particles. Our analysis shows distinct similarities as well as deviations compared to existing theories and bench-scale experiments. The study confirms anisotropic and non-Maxwellian distribution of fluctuating velocity components. The velocity distribution functions (VDFs) corresponding to transverse fluctuations exhibit symmetry, and follow a stretched-exponential behavior up to three standard deviations. The form of the transverse VDF is largely determined by interparticle interactions. The tails become more overpopulated with an increase in particle loading. The observed deviations from the Gaussian distribution are represented using the leading order term in the Sonine expansion, which is commonly used to approximate the VDFs in kinetic theory for granular flows. The vertical fluctuating VDFs are asymmetric and the skewness shifts as the wall is approached. In comparison to transverse fluctuations, the vertical VDF is determined by the local hydrodynamics. This is an observation of particle velocity fluctuations in a large-scale system and their quantitative comparison with the Maxwell-Boltzmann statistics.

Research Organization:
National Energy Technology Laboratory (NETL), Pittsburgh, PA, Morgantown, WV (United States); Oak Ridge Inst. for Science and Education (ORISE), Oak Ridge, TN (United States)
Sponsoring Organization:
USDOE Office of Fossil Energy (FE)
OSTI ID:
1440341
Report Number(s):
NETL-PUB-21279; TRN: US1900717
Journal Information:
Physical Review Fluids, Vol. 2, Issue 11; ISSN 2469-990X
Publisher:
American Physical Society (APS)Copyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 6 works
Citation information provided by
Web of Science

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Figures / Tables (4)

FIG. 1(p. 2)figure FIG. 1
FIG. 2(p. 4)figure FIG. 2
FIG. 3(p. 4)figure FIG. 3
FIG. 4(p. 5)figure FIG. 4

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Related Subjects

97 MATHEMATICS AND COMPUTING
42 ENGINEERING
fluid-particle interactions
fluidized beds
interparticle interactions
particle-laden flows