Screw pump CFD Simulation, ANSYS Fluent Training

Description

Description

The present problem simulates a screw pump at work using ANSYS Fluent software. A screw pump is a positive-displacement pump that uses one or several screws to move fluid solids or liquids along the screw(s) axis.

A single screw rotates in a cylindrical cavity, thereby gravitationally trapping some material on top of a section of the screw as if it was a scoop and progressively moving the material along the screw’s axle until it is discharged at the top.

The present model is designed in three dimensions using Design Modeler software. The model includes two zones the fluid zone is modeled for an open channel and one rotating zone for a screw pump.

The screw pump itself inclines 40 deg and has a length of 7 m. screw pump pitch is 0.5 m. We carry out the model’s meshing using ANSYS Meshing software, and the mesh type is unstructured. The element number is 3,886,425.

Methodology: Screw pump CFD Simulation

The Mesh Motion method is enabled to simulate the rotational motion of the pump. To model different phases of the solution, the Volume of Fluid (VOF) model is selected. The Open Channel model is also used to define the open channel boundary condition. Definitive density is equivalent to air density, i.e., 1.225 kg.m-3. The simulation is Transient.

Conclusion

According to the simulation animation, you can see how a screw pump works, and how it transfers water from the downstream channel to the upstream. The pressure contour shows the increase in pressure at the bottom of the pump wall, which has increased due to the presence of water.

On the other hand, the time taken to transfer water from downstream to upstream is equal to 141 seconds. The calculated pump head is equal to 2.5 meters at a circulation speed of 2 radians per second.