Implementation of Two Fluid Model for Dilute Gas Solid Flow in Pipes With Rough Walls

Abstract

A numerical study was carried out to investigate the performance of a twolayer model for predicting turbulent gasparticle flows in rough pipes. An Eulerian–Eulerian twofluid formulation was used to model both the gas and solid phases for turbulent gasparticle flow in a vertical tube. The stresses developed in the particle phase were calculated using the kinetic theory of granular flows while the gasphase stresses were described using an eddy viscosity model. The twofluid model typically uses a twoequation kة› model to describe the gas phase turbulence, which includes the suppression and enhancement effects due to the presence of particles. For comparison, a twolayer model was also implemented since it has the capability to include surface roughness. The current study examines the predictions of the twolayer model for both clear gas and gassolid flows in comparison to the results of a conventional low Reynolds number model. The paper specifically documents the effects of surface roughness on the turbulence kinetic energy and granular temperature for gasparticle flow in both smooth and rough pipes.