Challenge

Centrifugal pump design and analysis

Aim :- To design a centrifugal pump and analyse the flow through it & Obtain the relationship between Pressure ratio and mass flow rate

Objective :-

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. 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 a vacuum cleaner. The reverse function of the centrifugal pump is a water turbine converting potential energy of water pressure into mechanical rotational energy.

3d Part / Model :-

Flow analysis :-

The parametric study was ran for six different velocity values as :- V=10,20,30,40,50,60.
The cutplot for the velocity and pressure were obtained for different velocity values
Similarly the flow trajectories for the velocity and pressure flow were also obtained from the study
The parametric study was ran for the 500 iterations for each velocity value
The basic flow simulation for V=10m/s is shown in below video & cutplot and flow trajectories for the further velocity and pressure flow are shown below
https://youtu.be/s4--ykECWLs

Velocity Cutplot :-

Velocity Flow Trajectories :-

Pressure Cutplot :-

Pressure Flow trajectories :-

Cutplot Observation :-

for the velocity cutplot when the inlet velocity increases the flow velocity seems to be increasing with it
The water when enters the pump (indicated by the blue color) is having zero velocity as shown but when it exits its velocity is increased by a certain amount ie for the increase in outlet velocity values to 20 , 30 , 50m/s the flow velocity also increases in each case and thus the outlet flow seems to be in red color with increased velocity flow rate
Similarly for the pressure cutplot the pressure seems to be created around the impeller blades as the flow velocity increases , the Continuous flow of inlet water and the rotary motion of the impeller generates high Pressurized flow having the negative value at outlet
the flow at output ( indicated by blue color in flow trajectories and cutplot ) shows the high pressurized flow leaving the pump and has negative pressure value as it is subjected to surrounding

Explanation :-

Software used solid works 2016
Starting by modelling the 3D model for the centrifugal pump
Using the proper dimensions and the extrude function to create a fully defined model
Now to start with the flow analysis
Impeller speed was set to 1000 rpm
The parametric study was ran for 500 iterations for each velocity value
Providing the boundary conditions as environmental pressure at inlet and outlet velocity at exit lid/outlet & running the base line simulation
providing the surface goal for pressure and mass flow rate
The cutplot for velocity and pressure were used to visualize the flow
Now the new parametric study was ran for six different outlet velocity values as 10,20,30,40,50,60
After the completion of parametric study we obtain the surface goal for the mass flow rate and the clut-plot for each case
Lastly obtained the graph or plot for the each goal values

Graphs / Plots :-

the values for avg total pressure at inlet and outlet for varying velocity is shown below and also the graphs for the same is shown
The mass flow rate values at outlet were calculated and graph is plotted for the same is shown below

Graph/Plot Observation :-

For the avg total pressure 1 the graph seems to have negative values as the velocity value increases
For the avg total pressure 2 at the point 5 and 6 there is big pressure drop is seen
The graph for the total pressure 1 is for the outlet lid and it gives negative result ie because when flow exits to surrounding the pressure values are always negative
The mass flow rate also seems to have negative value because at the outlet mass flow rate is always negative and graph shows increase in mass flow rate as velocity increases
The pressure ratio plot is just the ratio of Outlet total pressure/ Inlet total pressure and it looks mostly similar to the total pressure plot 1

Result :-

Thus we have studied the flow analysis in the centrifugal pump
moddled the centrifugal pump and ran the flow analysis
Obtained the cutplot & flow trajectories for velocity and pressure at different velocity values
Obtained the graphs for the avg pressure,mass flow rate and pressure ratio

Conclusion :-

Thus the mass flow rate increases due to increase in velocity but tends to have negative value as it is an outlet mass flow rate
from the graph it is concluded that mass flow rate increases and pressure ratio also seems to increase in negative direction (as it falls out to the surrounding )
from the cutplot it is observed that the flow seems to have more velocity and pressure at the outlet

Ship work like this
in your own course.