Computational Study of Turbulent Gas-Particle Flow in a Venturi

Abstract

A “two-fluid” model has been applied to predict turbulent dilute gas-particle flow through a Venturi tube. Bulk motion of particles is considered as a secondary fluid flow which exchanges mass and momentum with the primary conveying air stream. Closure of the time-averaged equations is achieved by modelling turbulent second-order correlations with an extended mixing-length theory. Proposed closure model is found to aptly simulate the dependency of the static pressure drop on the particle size, flow rate and the loading ratio.

Fluid and sediment dynamics of upper stage plane beds

“…apply to sediment particles only [e.g.,Chung et al, 1986;Rizk and Elghobashi, 1989]. If it is assumed that -u'v' decreases linearly from the bed, as it does for the fluid, es can be expressed using an equation analogous to (For the mobile upper stage plane bed, vertical profiles of (a) dimensionless eddy viscosity and (b) mixing length determined for the sediment values (symbols).…”

Turbulent Gas-Solid Flows, Part I: Direct Simulations and Reynolds Stress Closures

“…Based on these studies, the secondary viscosity is negligible for small volume fractions, especially when Reynolds stresses are present. In wall-bounded¯ows and in the region close to the wall, this viscosity becomes important [31,32]. Since we are not concerned with wall-bounded¯ows and are dealing with small volume fractions, the extra viscosity is not included.…”

Experimental and numerical investigation of particle transport in a horizontal pipe

“…1 and 2 will have additional terms that can be obtained by Reynolds decomposing and time averaging of the equations, cf. for example,18, 20, 34. These additional terms will, for example, be correlations between fluctuating velocities and fluctuating particle concentration.…”