Centrifugal pump design and analysis

Aim:- Analysis of Centrifugal pump and to obtain relation between pressure ratio and mass flow ratio 

Introduction:-

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. A centrifugal fan is commonly used to implement an air handling unit or vacuum cleaner. The reverse function of the centrifugal pump is a water turbine converting potential energy of water pressure into mechanical rotational energy.

                                             Section view of Centrifugal Pump

 Procedure:-

1. Making geometry of the pump

                                  Impeller is made as per arbitary geometry 

Near the blade of centrifugal pump, a cylindrical body is made to rotate the fluid near for more precise result

     Casing of the pump is made such that is little clearance from the impeller blades 

                             Making Control Volume so as to rotate the fluid inside the casing .

Setup :-

To provide sufficient fluid particles near the impeller , a rotating region is made which also rotates

Inlet Boundary Condition 

Environmental Pressure is applied at inlet boundary of 101325 Pa

Outlet Boundary Condition

At the outlet of the pump velocity of 10 m/s is applied .

Setup of Parametric Study

Input Variables velocity at outlet of pump is varied from 10 m/s to 20 m/s 

Output Parameters are added of mass flow rate and total pressure at outlet 

Results :- 

                                       Parametric Analysis Result 

Mass flow rate and Pressure Ratio 

                                                                               Mass flow Rate and Total Pressure 

                                                             Velocity of the pump 

                                                                 Flow Trajectory

Observations and Conclusion:- 

1. From the plot we can see that intially velocity is less mass flow rate is low as the velocity increases mass flow rate increases.

2.Also the outlet pressure increases as to maintain the outlet velocity at the increasing rate .