skip to Main Content

Sedimentation in Urban Sewer Conduits, CFD Simulation

Rated 0 out of 5
(be the first to review)


The present problem simulates sand particle sedimentation in a water flow channel using ANSYS Fluent software.

This product includes a Mesh file and a comprehensive Training Movie.

There are some free products to check our service quality.

To order your ANSYS Fluent project (CFD simulation and training), contact our experts via [email protected], online support, or WhatsApp.


Project Description

The present problem simulates sand particle sedimentation in a water flow channel using ANSYS Fluent software. The sedimentation phenomenon is one of the destructive phenomena in the quality of performance of any equipment. Sedimentation can occur when the base fluid contains excess soluble particles. For example, if water flows along with sand particles into a canal, and the channel has obstacles in its path, or there is a sudden change of direction within the channel, a sedimentation phenomenon occurs; Because in areas with obstacles and with a sudden change of direction, dissolved sand particles locally relative to the main water flow becomes stagnant and slows down.

In the present simulation, the Eulerian-Lagrangian perspective on computational fluid dynamics (CFD) is used; So that the Eulerian multiphase model is coupled with the dense discrete phase model (DDPM). A continuous phase is defined, which is related to water flow, and a discrete phase is described, which is related to sand particles. The material of sand is defined as stagnant particles that have a density equal to 2650 kg.m-3. The water flows with a flow rate of 15 kg.s-1 enters the channel horizontally. Simultaneously, the flow of sand particles enters the channel discretely with a flow rate of 0.21 kg.s-1 and a velocity of 0.083 m.s-1.

The discrete sand particles diameters are defined as variable, including a minimum diameter of 0.00001 m, a maximum diameter of 0.0002 m, and an average diameter of 0.000131 m.

Geometry & Mesh

The present model is designed in three dimensions using Design Modeler software. The model consists of a computational area in the form of a horizontal channel with a square cross-section in which the flow of water and particles moves horizontally inside. On the lower surface of the canal, three rows of plates or diagonal barriers are designed that can help the sedimentation phenomenon.


We carry out the model’s meshing using ANSYS Meshing software, and the mesh type is structured. The element number is 14280. The following figure shows the mesh.


Sedimentation CFD Simulation

We consider several assumptions to simulate the present model:

  • We perform a pressure-based solver.
  • The simulation is steady.
  • The gravity effect on the fluid is equal to -9.81 m.s-2 along the Y-axis.

The following table represents a summary of the defining steps of the problem and its solution:

Viscous k-epsilon
k-epsilon model standard
near wall treatment standard wall functions
turbulence multiphase model dispersed
Multiphase Model Eulerian
eulerian parameters dense discrete phase model
formulation implicit
number of eulerian phases 1
discrete phase model On
Boundary conditions
Inlet Mass Flow Inlet
mass flow rate – water 15 kg.s-1
discrete phase BC type escape
Outlet Pressure Outlet
gauge pressure 0 pascal
discrete phase BC type escape
Outer Walls Wall
wall motion stationary wall
dpm conditions reflect
Baffles Wall
wall motion stationary wall
dpm conditions reflect
Symmetry Symmetry
Pressure-Velocity Coupling Phase Coupled SIMPLE
Pressure PRESTO
momentum first order upwind
turbulent kinetic energy first order upwind
turbulent dissipation rate first order upwind
volume fraction first order upwind
volume fraction first order upwind
Initialization methods Standard
gauge pressure 0 Pascal
velocity (x,y) for water 0 m.s-1
z-velocity for water -0.1252254 m.s-1
velocity (x,y,z) for sand 0 m.s-1

Sedimentation Results & Discussions

At the end of the solution process, two-dimensional contours related to water pressure and velocity, and three-dimensional contours related to water pressure and velocity, and a particle sequence based on the residence time and particle diameter is obtained. For example, the particle sequence indicates that water-soluble particles accumulate in the front area of the barrier after hitting the initial oblique barrier. Thus, the sedimentation phenomenon is possible.

There are a Mesh file and a comprehensive Training Movie that presents how to solve the problem and extract all desired results.


There are no reviews yet.

Leave a customer review

Your email address will not be published. Required fields are marked *

Back To Top
you tube
Call On WhatsApp