Header menu link for other important links
X
Effects of particle diameter and position on hydrodynamics around a confined sphere
Published in
2011
Volume: 50
   
Issue: 23
Pages: 13137 - 13160
Abstract
The effect of confinement of a sphere within a tube on the hydrodynamics of Newtonian fluid flow around the solid surface is investigated. The ratio of particle diameter to tube diameter (blockage ratio), the ratio of sphere distance from the tube axis to the tube diameter (eccentricity), and the fluid flow rate were the parameters of this study. Computational fluid dynamics (CFD) simulations were carried out to obtain the flow field around the sphere from which the angle of boundary layer separations, as well as drag and lift coefficients, were obtained. The pressure distributions and friction factor along the sphere surface are also reported. To estimate the effect of confinement and eccentricity in position of the particle, with respect to the tube axis, the results are compared with the classical case involving the flow of an unbounded fluid over the sphere. The drag coefficient diminished when the particle was positioned eccentrically with respect to the tube axis at very low particle Reynolds number (Rep). However, the drag coefficient increased with increasing eccentric positions at higher Rep. At eccentric particle positions, boundary layer separation occurred earlier from the upper hemisphere while, depending on the eccentricity, it was delayed or nonexistent in the lower hemisphere. The difference in pressure between the lower and upper hemisphere regions led to incursion of fluid into the upper hemispherical region. Correlations are proposed for the drag and lift coefficients in the range of 0.1≤ Rep ≤ 500 for different possible eccentricities and blockage ratios. The results from this work will be of relevance in applications such as fluidization and aseptic food processing. © 2011 American Chemical Society.
About the journal
JournalIndustrial and Engineering Chemistry Research
ISSN08885885
Open AccessNo
Concepts (27)
  •  related image
    Blockage ratio
  •  related image
    Boundary-layer separation
  •  related image
    Computational fluid dynamics simulations
  •  related image
    Friction factors
  •  related image
    LIFT COEFFICIENT
  •  related image
    NEWTONIAN FLUID FLOW
  •  related image
    Particle diameters
  •  related image
    PARTICLE POSITION
  •  related image
    Particle reynolds number
  •  related image
    Solid surface
  •  related image
    SPHERE SURFACES
  •  related image
    Tube diameters
  •  related image
    UNBOUNDED FLUID
  •  related image
    Boundary layers
  •  related image
    Computational fluid dynamics
  •  related image
    Drag
  •  related image
    Drag coefficient
  •  related image
    Flow of fluids
  •  related image
    Fluidization
  •  related image
    FLUIDS
  •  related image
    Food processing
  •  related image
    Hydrodynamics
  •  related image
    Lift
  •  related image
    Particle size
  •  related image
    Reynolds number
  •  related image
    Tubes (components)
  •  related image
    Spheres