Measurement of turbulent stresses in a gas-solid fluidized bed

Conference · Wed Jan 01 04:00:00 EST 1986

OSTI ID:6417523

Moslemian, D; Chen, M M; Chao, B T

Turbulent stresses experienced by particulate phase in a gas-fluidized bed are evaluated from measured instantaneous velocities of solids using a particle tracking facility. Glass beads ranging from 425 to 600 ..mu..m and from 625 to 800 ..mu..m and superficial gas velocities of 2.5, 4.5, and 6.0 times the minimum fluidization velocities were used. In this particle tracking facility, the gamma radiation emitted from a radioactive tracer particle, which is dynamically identical to the bed particles and is mixed into the bed, is continuously monitored by a large number of scintillation detectors to provide direct experimental determination of both time-averaged and the fluctuating solids velocities as well as the particulate phase density. The turbulent shear stress, -rho<..mu../sub r/'..mu../sub z/'>, is obtained from the cross correlations of solids fluctuating velocities. The turbulent normal stresses, -rho<..mu../sub r/'/sup 2/> and -rho<..mu../sub z/'/sup 2/>, are determined from the Lagrangian velocity autocorrelations. Such information are useful in the formulation of momentum conservation equations and the development of realistic hydrodynamic models for gas solid fluidized beds, which in turn are essential for developing scale-up relations.

• Research Organization: Univ. of Illinois at Urbana-Champaign, Dept. of Mechanical and Industrial Engineering, 1206 West Green Street, Urbana, IL 61801
• OSTI ID: 6417523
• Report Number(s): CONF-861146-
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420400* -- Engineering-- Heat Transfer &amp; Fluid Flow
DETECTION
FLOW MODELS
FLOW RATE
FLUID FLOW
FLUID MECHANICS
FLUIDIZED BEDS
GAMMA DETECTION
GAS FLOW
GLASS
HYDRODYNAMICS
ISOTOPE APPLICATIONS
MATHEMATICAL MODELS
MECHANICS
RADIATION DETECTION
SHEAR
SOLIDS FLOW
STRESS ANALYSIS
TRACER TECHNIQUES
TURBULENCE
TURBULENT FLOW
TWO-PHASE FLOW