Modeling of Turbulence Modification Using Two-Time-Scale Dissipation Models and Accounting for the Particle Wake Effect

The presently developed two-phase turbulence models under-predict the gas turbulent fluctuation, because their turbulence modification models cannot totally reflect the effect of particles. In this paper, a two-time-scale dissipation model of turbulence modification, including a two-time-scale dissipation model for the two-phase velocity correlation and a two-time-scale dissipation model for the dissipation rate of gas turbulent kinetic energy, is proposed and used to simulate swirling gas-particle flows with a swirl number of 0.47. Besides, a gas turbulence augmentation model accounting for the finite-size particle wake effect in the gas Reynolds stress equation is proposed. The proposed turbulence modification models are used to simulate two-phase pipe flows. It can predict not only the turbulence reduction by small particles but also the turbulence enhancement by large particles.