CFD for Water Treatment: Modeling of sludge settling (SVI)

CFD SVI TEST
Multiphase Simulation of sludge settling, as it is conventionally carried out in SVI-tests (Sludge Volume Index).
With CFD it is possible to model all relevant parameters in order to correctly simulate water-sludge mixtures in stirred tank reactors or in settling reactors such as clarifiers.
In this Simulation, the following parameters were taken into consideration: density of water and particles, normal distribution of particle size in a common range for sludge-flocks in biological reactors, viscosity of the fluid as a function of solid concentration, drag corrections as a function of solid concentration.
Furthermore when experimental data is available it is possible to use it to setup the numerical model even with higher precision: An example of it is the Sludge Volume Index (SVI) or better, a settling curve of an specific sludge probe.

[@yangliu2156]

hello, i was trying to simulate sludge settling with Openfoam ,but it didnt work, i think there maybe something wrong with my boundary conditions.
Can u pls tell me what is ur set-up of the boundary conditions.