Granular Flows Group







A granular material flow is a form of two-phase flow consisting of particulates and an interstitial fluid. When sheared the particulates may either flow in a manner similar to a fluid, or resist the shearing like a solid. The dual nature of these types of flows makes them very difficult to analyze.

Many examples of granular flows can be found in both industry and nature. Hoppers, chutes, and conveyor belts are used when transporting particulate materials such as food stuffs, pharmaceuticals, and coal. Fluidized bed reactors are commonly used for chemical reactions involving a solid and a liquid (or gas). Other industrial applications include packing of granular materials, particulate segregation and mixing, and particulate drying. In nature, examples of granular flows include avalanches, river sedimentation, dune formation, planetary ring dynamics, soil liquifaction, and ice flow mechanics. Clearly, understanding the behavior of granular materials will provide useful information.


Research Interests of Our Group

Dry Granular Flows

  • Diffusion and Mixing
    • Kinetic Theory Analysis
    • Local Velocity Measurements
    • Local Diffusion Coefficients
    • Heat Transfer
    • Segregation
    • Shear-Induced Heat Generation
  • Response to Vibration
    • Horizontal Layer - Wave formation and instabilities
    • Computer Simulations
    • Effect on Discharge from a Hopper
    • Horizontal vibration
  • Electrostatic Charging
    • Toner particle flows
    • Mixing and Segregation of Binary Mixtures of Charged Particles

Liquid-Solid Flows

  • Liquid Fluidized Beds
    • Particle Pressure Measurements
    • Measurement of the Fluctuating Component of the Solid Fraction
    • Gravity-Driven Pipe Flow
    • Segregation of Binary Mixtures
  • Immersed Collision of Particles
    • Effect of Fluid Properties in Particle Collision and Rebound
    • Fluid Pressure Generated as a Result of Particle Collisions
    • Mixing and Turbulence Generated as a Result of Particle Collisions


  • Electrophotography
    • Radiant Absorption
    • Melting
Dr. Melany Hunt
Mechanical Engineering Department
California Institute of Technology
Mail Code: 104-44
Pasadena, CA 91125
PHONE: 626-395-4231, FAX: 626-568-2719

Granular Flows Group,