Sludge Flow In Centrifugal Pump CFD Simulation

Description

Sludge Flow In Centrifugal Pump CFD Simulation, ANSYS Fluent Tutorial

Description

The performance of centrifugal pumps is significantly impacted by the distinctive properties of sludge flow with a particle concentration greater than 50%.  The high particle concentration increases the sludge’s viscosity and density, making it harder to pump.

The thickening and weight gain of the sludge causes higher friction losses inside the pump system. Because of the increased resistance, the pump has to work harder to push through the friction and keep the flow rate constant. In addition, sludge with a high particle concentration can severely wear and abrade the impeller and other pump parts.

This product uses ANSYS Fluent software to stimulate the sludge flow inside a centrifugal pump. We perform this CFD project and investigate it by CFD analysis.

We designed a centrifugal pump in which the computational domain consists of rotating and stationary zones. The flow enters the pump through the stationary part entrance and then turns into the rotational zone. The rotating region of the pump rotates with a rotational speed equal to 1000 rpm then the flow finds its way to the pump outlet.

First, we simulated water flow using the SST k-w turbulence model to see the flow behavior through a centrifugal pump, the range of pressure drop, the velocity contour, and the other results, such as streamlines, shown in the results.

Second, we simulated the sludge flow, including water as the base fluid and calcium carbonate as particles with 50% and 60% concentration, respectively, using a multiphase mixture model, which can account for solid particles suspended in a liquid medium.

We modeled the geometry of the project using Design Modeler software. Then we meshed the model with ANSYS Meshing software. The mesh model is polyhedral, and the number of cells equals 1,498,132.

Sludge Flow In Centrifugal Pump Methodology

In this problem, the mixture model solves the sludge flow by considering water and calcium carbonate as the first and second phases. The Schiller-naumann model is chosen to model the drag coefficient.

Multiple Reference Frames (MRF) model has been applied for the rotation simulation. The diameter of particles is considered equal to 100 µm. The SST k-w turbulent modal is used for both water and slurry flow.

Conclusion

The pressure, velocity, volume fraction and turbulence intensity contours, velocity vectors, and path lines are presented for the pure water and mixture model. These results show the behavior of both water and sludge flow through a centrifugal pump. Also, you can see the effect of increasing sludge concentration on pressure, velocity contours, and turbulence intensity.