Numerical modelling of particle laden flows with a four-equation model

The computational model, involving transport equations for momentum and for turbulent quantities for a continuous and a monodisperse phase interacting with each other in the framework of the two-fluids, Euler/Euler approach is presented. The background turbulence model uses eddy viscosity as the model parameter. In addition to dynamic equations for the turbulent kinetic energy k and its dissipation rate epsilon of the continuous phase, the model employs transport equations for the turbulence kinetic energy and for the covariance of velocities of the disperse and continuous phase q, characterizing turbulence of the disperse phase. A central differencing scheme was applied to avoid an unrealistic constant value of the volumetric fraction The model was validated through computations of the particle laden, fully developed channel flow (Exp.: Kulick et al., 1994) and flow over a backward-facing step (Exp.: Fessler et al., 1999). The results obtained using the present model were also compared with the results obtained by an Euler/Lagrange scheme.