Centrifugal pump design and analysis

Aim: To perform the flow simulation through centrifugal pump and obtain the relation between pressure ratio and mass flow rate by modelling the centrifugal pump using solidworks.

Objective:

To determine the perform diagram.

Theory:

Centrifugal pumps are used to transport fluids by the conversion of rotational kinetic energy to the hydrodynamic energy of the fluid flow. The rotational energy typically comes from an engine or electric motor. They are a sub-class of dynamic axisymmetric work-absorbing turbomachinery. The fluid enters the pump impeller along or near to the rotating axis and is accelerated by the impeller, flowing radially outward into a diffuser or volute chamber (casing), from which it exits.

Common uses include water, sewage, agriculture, petroleum and petrochemical pumping. Centrifugal pumps are often chosen for their high flow rate capabilities, abrasive solution compatibility, mixing potential, as well as their relatively simple engineering.

Mass flow rate:

The mass flow rate of a system is a measure of the mass of fluid passing a point in the (m) system per unit time.The present study aims to analyse the fluid flow in a flowbench and determine the perform diagram.

Pressure ratio:

Pressure ratio is the ratio between the outlet pressure and the inlet pressure.

Pressure ratio = Outlet total pressure / Inlet total pressure

The present study aims to analyse the performance diagram and obtain the relationship between pressure ratio and mass flow rate and explain the results.

Problem statement:

For this project, you will have to show the following

• Performance diagram. Obtain the relationship between Pressure ratio and mass flow rate and explain your results.
  

• Pressure ratio = Outlet total pressure/ Inlet total pressure

Geometry modelling

In this project, a 3D model of centrifugal pump is created using solidworks CAD software.

Parameters for Baseline simulation

Sr.No.	Parameters
1	Analysis type	Internal
2	Fluid used	Water
3	Type of flow	Laminar and turbulent
4	Rotation type	Local region averaging
5	Boundary condition at inlet	1 bar
6	Boundary condition at outlet	10 m/s

• Results

• Design point 1 @ velocity 10 m/s

Velocity plot

Pressure plot

Flow trajectories

• Design point 2 @ velocity 20 m/s

Velocity plot

Pressure plot

Flow trajectories

• Design point 3 @ velocity 30 m/s

Velocity plot

Pressure plot

Flow trajectories

• Plot for mass flow rate and total pressure

• Conclusion
• As the velocity increases mass flow rate also increases.
• Pressure ratio is high for low velocity and pressure ratio starts to decreases when velocity increases.
• A pump does not create pressure it only creates flow. Pressure is a measurement of the resistance to flow.