Numerical investigation of a two-phase flow of fluid with light particles in open channels

A mathematical model and a computational method for a numerical investigation of the twophase turbulent flow in an open channel are performed. The solid particles with a density close to that of water were considered as a dispersed phase. The model is based on the flow depthaveraged equations of mechanics of interacting and interpenetrating continuums in a hydrostatic approach. A turbulent closure of the model is implemented with the application of the $k-\varepsilon$ turbulence model modified by Pourahmadi and Humphrey (1983) to consider the influence of particles on the turbulent structure of the flow.
The numerical method proposed for solving equations of the model is based on the elimination algorithm and explicit-implicit time approximation.
An unsteady turbulent flow in a 180-degree bend flume with polypropylene particles modeling the ice was computed and the results were compared with those of Urroz and Ettema (1992). It was found that the mathematical model and the computational method proposed predict accurately both the velocity field and distribution of the particles in the channel.
The influence of the dynamic parameters of dispersed phase on the turbulent structure of the flow was investigated by conducting the calculations of the flow in an open channel with a 90-degree bend. It was revealed that the structure of a two-phase flow is most affected by the size and shape of the particles.