Carrier Phase Turbulence in Fluid-Particle Flows (Plenary)

Turbulence in the carrier phase of fluid-particle flows plays an important role in mixing and shear stress. The availability of a reliable model for turbulence is essential to the development of computational models that can be applied with confidence to engineering systems. The general approach is to add a term to the Navier-Stokes equations that represents the force on the fluid due to due to particle drag and to carry out the procedures used for single phase flows to derive equations for carrier-phase turbulence. The problem with this approach is presented. A flow configuration representing a basic test case, which can be used to judge the viability of any model, is introduced. A recently developed turbulence model using volume averaging and based on the turbulence energy-dissipation description of turbulence is presented. This model is applied to the basic test case and to experiments for particles dropping in a quiescent fluid and gas-particle vertical channel flow. The predictions show good agreement with experimental data.