Large eddy simulation of the turbulent multiphase flow on sandstone wastewater of hydropower stations in a vortex-type grit chamber

Abstract

Vortex-type grit chambers are commonly used for the treatment of high-turbidity sandstone wastewater in hydropower stations. Current researches on vortex-type grit chambers mainly focus on the optimization of the engineering operation parameters. Although there have been many studies on sandstone wastewater simulations in stirred tanks or hydrocyclones predicted by Reynolds-averaged Navier–Stokes, there are few reports on the large eddy simulation (LES) based prediction of the multiphase flows in a vortex-type grit chamber. The rigid-lid approximation is commonly used for free surface movement. The LES can reveal more detailed pulsation features. The volume of fluid (VOF) method can describe the interfacial turbulence characteristics for free surface movement. Thus, the VOF method was used as a surface tracking technique along with LES–Lagrangian model to study the characteristics of gas–liquid–solid multiphase flows. The flow field distributions were analyzed and the micro movement regularities of particles were discussed.