Description

In this project, the fluid flow and structural dynamics within a centrifugal pump have been simulated using ANSYS Fluent software.  We perform this CFD project and investigate it by CFD analysis.

The present model is designed in 3-D using the Design Modeler. The geometry is related to a centrifugal pump, so several blades are designed in the central zone of this pump.

The fluid enters from the outside of the pump and, after rotating around the blades, exits axially from the center of the pump.

The meshing of this present model has been generated by Ansys Meshing software. The total cell number is more than 3649835.

Centrifugal Pump Methodology

The present problem is the flow simulation inside a centrifugal pump via ANSYS Fluent. In general, pumps are industrial equipment that causes fluids to move from one part to another using mechanical action.

Pumps are classified into two main categories: dynamic and positive displacement pumps. There are different types of dynamic pumps, one of the most common of which are centrifugal pumps.

The operation of centrifugal pumps increases the fluid pressure from the inlet to the pump's outlet, causing the fluid to move. The force that creates this pressure is supplied by an electric motor that rotates the impeller.

The fluid in this pump enters the center of the impeller and exits the edge of its blades. So the centrifugal force increases the velocity and kinetic energy of the fluid.

In this project, the pump consists of three main parts; The central blades are defined as a solid body, and the casing around the pump is defined as the fluid passage. A distinct central zone is defined for the fluid section so that the rotational motion of the pump blades can be applied to it.

Therefore, for this central fluid zone, the frame motion method is used, and the rotational speed value of 1500 rpm is defined; This means that the fluid rotates around the rotating blades at this speed.

Also, water flow enters from the pump's inlet port with a speed of 140 m/s radially and exits axially in the central part of the pump with a relative pressure of 0 pascals.

Moreover, the SST k-omega model is used to solve turbulent fluid equations due to its advantage in accurately predicting flow patterns near and far from the walls.

In this project, to accurately simulate the interaction between the fluid flow and the structural dynamics of the pump components, a Fluid-Structure Interaction (FSI) model is employed. This approach allows for capturing the deformation of the pump blades under fluid forces, ensuring a realistic depiction of the fluid-structure coupling.

Centrifugal Pump Conclusion

The contours show that the pressure increases radially; By increasing the pressure from the pump's central part to the periphery.

Also, due to the rotational motion of the pump in the central part, you can see the maximum speed in this part and the maximum value of the pressure difference or pressure gradient. The integration of the FSI model within the simulation provided critical insights into the structural dynamics of the impeller blades, contributing to a more robust understanding of the centrifugal pump’s operational efficiency and potential failure points under dynamic load conditions.