Turbulence structure of liquid-solid two-phase channel flow (2nd report, two-time-scale particle-laden turbulence model)

A two-time-scale model for particle-laden turbulent flows has been developed to represent the interactions between dispersed particles and fluid turbulence. Experimental evidence has shown that smaller particles attenuated the turbulence, inducing an increase in energy in the high-wave-number region of the energy spectrum, which is attributed to the extra dissipation by the particles. On the other hand in the case of larger particles, the energy increased in both the low- and high-wave-number regions, due to the particle concentration fluctuation. The present modeling, therefore, divides the energy-containing part of the spectrum into two regions. A two-way coupling method between Particle Lagrangian Simulation and the two-time-scale Eulerian k-e model has been applied to liquid-solid and gas-solid channel flows. The proposed model has the ability to predict turbulence modification by the presence of particles.