Project Description

In this project, the impure water flows in an obstruction channel using ANSYS Fluent software. The aim of the study is to determine the obstacle effect on water pathlines and how it can cause damage to the channel over time. As a result, the Discrete Phase Model (DPM) module is used to simulate sand particles and erosion/accretion.

This product is the 5th chapter of the DPM training course.

The geometry is designed in ANSYS Design Modeler software. Then, it was meshed by ANSYS Meshing software. A structured mesh grid is generated which leads to 1155000 quad elements.

Methodology(Erosion In An Obstruction Channel)

The discrete phase model (DPM) is used to inject 1mm in diameter sand particles. It`s a two-way DPM coupling because the dense sand particles could affect the continuous phase. Note that, due to the nature of the Erosion/Accretion phenomena, the steady-steady solver is performed.

Conclusion

After the simulation, the two-dimensional contours clearly depict the effect of sand particles and the obstacle on the channel wall. The high-velocity (15m/s) inlet and collision with the obstacle result in an extreme pressure gradient, especially near the top wall of the channel. As can be seen in the velocity contour, the flow velocity reaches 93.5m/s as its maximum.

In addition, the residence time contour shows that the particles cover a 5-meter distance in less than 0.2 seconds which is another proof of high-velocity flow! This process led to erosion over time specifically behind the obstacle and on the top wall of the channel. These results are visible in erosion/accretion contours, no matter which theory you obtain (Oka, Mclaury, Finnie,..)