Abstract
Representative phenomena of solid fluid two-phase in nature are snowdrift and suspension flow in an open channel. The numerical analysis using the turbulent diffusion equation and the k-ε turbulence model is carried out. The agreement between the experimental data and the numerical analysis for both cases is well. The flow can be reproduced by the numerical analysis. The near-bed boundary condition for the turbulent diffusion equation is important and is expressed by the entrainment coefficient that is obtained from concentration flux of solid particles divided by the terminal velocity of particles. The idea of entrainment coefficient is effective for both flows. The values of the entrainment coefficient for snow particles and sediment particles are estimated by the numerical analysis and measurements. Based on these results, the effecttiveness of the entrainment coefficients is discussed comparing with the Garcia's experimental equation.
