Transport coefficients of solid particles immersed in a viscous gas
Vicente Garzó1, William D Fullmer2, Christine M Hrenya2
1Departamento de Física and Instituto de Computación Científica Avanzada (ICCAEx), Universidad de Extremadura, E-06071 Badajoz, Spain.
Physical Review. E
|February 13, 2016
Summary
This study examines gas-solid suspensions, focusing on thermal drag effects on transport properties like viscosity and thermal conductivity. Results show gas phase interactions significantly impact these properties, especially in dilute systems.
Area of Science:
- Fluid Dynamics
- Statistical Mechanics
- Granular Materials
Background:
- Transport properties in gas-solid suspensions are influenced by particle collisions and gas-phase interactions.
- Previous models often simplified gas-solid interactions, neglecting temperature-dependent friction effects.
Purpose of the Study:
- To investigate the impact of temperature-dependent friction on the transport coefficients of a gas-solid suspension.
- To analyze the role of "thermal drag" as the primary gas-solid interaction at zero mean relative velocity.
- To determine the conditions for stability of the homogeneous cooling state in such systems.
Main Methods:
- Utilized the Enskog kinetic equation and the Chapman-Enskog method to solve the thermal drag model.
- Determined Navier-Stokes transport coefficients (shear viscosity, thermal conductivity, Dufour-like coefficient) as functions of physical parameters.
- Performed a linear stability analysis of the hydrodynamic equations.
Main Results:
- The gas phase significantly affects shear viscosity (η*) and the Dufour-like coefficient (μ*), particularly in dilute suspensions.
- Thermal conductivity (κ*) retains the same form as in dry granular systems.
- The model shows good agreement with direct numerical simulations for practical conditions.
Conclusions:
- Temperature-dependent friction is a crucial factor influencing transport properties in gas-solid suspensions.
- The findings provide a more accurate understanding of energy and momentum transfer in these complex systems.
- The study offers insights into the stability of granular flows relevant to various industrial applications.
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