Hybrid cars

1. Design and Analysis of
Centrifugal Pump
Batch 1
Group 3
Vedant Girgaonkar - 15
Parikshit Gokhale - 16
Abhishek Govekar - 17
Nandita Gyanchandani -20
Shridnyan Haval – 25
Guide - Prof.
Dr. Laxmikant Mangate
HMAFP
Course Project

2. 2
Contents
•Classification of pumps
•Centrifugal Pump working and important parameters
•Design Calculations of Centrifugal Pump
•Motor Selection
•CFD Results
•Failures in Centrifugal Pumps

3. Classification of pumps
Positive Displacement Dynamic Pumps
3
Rotary Pumps
Reciprocating Pumps
Piston
Plunger
Diaphragm
Gear
Vane
lobe
Peristaltic
Screw
Progressive Cavity
Axial
Centrifugal Pumps

4. 4
Centrifugal Pump
● It pumps the fluids by converting
mechanical power(rotational energy)
into pressure energy of the fluid
● This mechanical power is supplied by
the electric motor or engine.
● A centrifugal pump uses centrifugal
force to pump the fluids & hence
called centrifugal pump.

5. 5
Centrifugal Pump - Construction
A] Rotating Components :
Impeller: Impeller is a rotor used to increase
the kinetic energy of the flow.
Shaft (Rotor): The impeller is mounted on a
shaft. Shaft is a mechanical component for
transmitting torque from the motor to the
impeller.
B] Stationary Components :
Casing (Volute): The casing contains the
liquid and acts as a pressure containment
vessel that directs the flow of liquid in and
out of the centrifugal pump.
Shaft sealing. Centrifugal pumps are provided
with packing rings or mechanical seal which
helps prevent the leakage of the pumped liquid.

6. 6
Centrifugal Pump - Working
➢ Pressure less than atmospheric pressure is
created at the eye.
HOW??
As the liquid moves towards the periphery from
the center of the impeller (the eye) a void is
created at the center or eye of the impeller,
hence creating a low pressure zone at the eye.
➢ The water from the eye is forced radially
outwards due to centrifugal force.
➢ Thus, increase in K.E. & Pressure energy
➢ Volute further increases the pressure energy
due to its characteristic shape.

7. 7
Centrifugal Pump - Priming
Source : https://chemicaltweak.com/pump-priming-in-detail/
Fig- Non-Primed and Primed Pumps

8. 8
Problem Statement and Assumptions
It is required to pump water over a 15 story building which is approximately
131 feet. The tank capacity which is to be filled by the water is about 81000
litres. It is required that the tank should be filled within 10 minutes. Design a
centrifugal pump and validate results using ANSYS.
Parameter Symbol Value Unit
Manometric Head Hmano 40 m
Speed Ratio Ku 1.25 -
Velocity Ratio Kf 0.25 -
Rotation Speed N 1000 rpm
Tank Capacity Vc 81000 L
Time Tc 600 sec
Flow rate(L/s) QL 135 L/sec
*Flow rate (m³/s) Qm 0.135 m³/s
*Minumum Outer Diam Dmin 0.617 m
Contraction Factor Kt 0.87 -
Table 1. Assumptions

9. 9
Design Calculations
We start the design of the pump by finding the value of φ for maximum manometric efficiency.
The maximum Manometric efficiency in terms of of φ is given by –
In order to find the value of φ we first have to find the value of u2 and Vf2. Now u2 and Vf2 is given by –
(1)
(2) (3)
Hence after substituting the values from Table 1, we get the values of u2 and Vf2 as
35.018 m/s and 7.0036 m/s respectively.

10. 10
Design Calculations
Substituting these values in eq. 1 we get a relationship between ηmano and φ. When
we plot this on a graph using excel result is obtained is Shown in Fig.1.
It is observed that Maximum Efficiency is obtained around 12 Degrees, But
this will lead to long and narrow blades with high friction loss. , Hence the
value of φ is taken above 20°. Hence the value of Outlet Tip angle is taken as
φ = 25°.
Fig.1 η and φ

11. 11
Design Calculations
Now once the values of u2 is known we can
find the inner and outer Diameter of the impeller.
The Diameter and Tangential Velocity are
related as –
(4)
Also in most of the cases D1=0.5*D2. Hence
values of D1 and D2 are 0.3344m and 0.6688m
respectively.
Now, The least or minimum diameter of an
impeller can be determined on the basics of the
fact that the pump will start delivering liquid
only when centrifugal head equals the total head
Hmano
(5)
If we substitute the values of u1 and u2 from Eq.(4)
for and then solve for D2 , we have –
(6)
Hence the value of Dmin Comes out to be 0.61778m.
As Dmin D2 , the value of D2 is safe.

12. 12
Design Calculations
Similarly is we solve Eq.(5) for Nmin we get
the following equation –
(7)
Hence the value of Nmin comes out to be
923.542 rpm.
As N >Nmin , The value of N is safe.
The Tank capacity is calculated based on the
number of residents living in a typical 15 story
building.
A 81000 L tank is considered . As this tank needs to
be filled within 10 minutes hence by dividing the
volume by the amount of time required we get the Flow
rate of water.
The Inner and Outer vane thickness is calculated by
using the following equation and Table 1.
Q = Area x Velocity of Flow
= πD2B2 × Vf × Kt
(8)
Hence, the values of inner vane thickness and outer
vane thickness are is B1=0.02108m and B2 = 0.01054m
respectively.

13. 13
Design Calculations
The inlet vane angle is found by uing the
following relation –
(9)
Hence the value for inlet vane angle comes
out to be 21.8005°.
Now as the value of θ is known we can
conveniently find the value of Vr1 by using the
following relation.
Now in order to define the outlet velocity triangle
we make the use of following equations –
(10)
Hence, Inlet velocity triangle gets fully defined
(10)
(11)
(12)
(13)
From the Eq.(11) we get the values of Vw2 as 19.98m/s. If
we substitute this value in eq.(12) we get the value of V2
as 21.1895m/s. Then we calculate the outlet tip angle (β)
by using Eq.(13) and it comes out to be 19.3004°. Lastly
we find the value of Vr2 by using Eq.(14) which comes
out to be 16.57m/s.

14. Velocity Triangle and Results
Figure 2 Inlet and Outlet Velocity Triangles
Parameter Symbol Value Unit
Tangential Velo at outlet u2 35.018 m/s
Tangential Velo at intlet u1 17.51 m/s
Flow Velocity at outlet Vf2 7.00 m/s
Flow Velocity at intlet Vf1 7.00 m/s
Outlet Vane Angle Φ 25.00 deg
Outer Diameter D2 0.67 m
Inner Diameter D1 0.33 m
Outer Vane Thickness B2 0.01 m
Inner Vane Thickness B1 0.02 m
Inlet Vane Angle θ 21.80 deg
Whirl Velocity at outlet Vw2 20.00 m/s
Whirl Velocity at inlet Vw1 0.00 m/s
Relative Velocity at outlet Vr2 16.57 m/s
Relative Velocity at inlet Vr1 18.86 m/s
Out let tip angle Β 19.30 deg
Table 2 – Results
14

15. 15
Motor selection

16. 16
CFD Results

17. 17
Centrifugal Pump Failures : Mechanical Failures
Bearing Failures : Contamination of bearing oil due to water, another liquid or solid particles,
high heat due to overloading.
Seal Failure : Pump running dry, opening of lapped faces.
Lubrication Failure : Overloading of bearings decrease viscosity and life span of the oil.
Excessive Vibrations : Impeller unbalance, problems in bearings, cavitation, movement in base
plate, air/vapour lock result in excessive vibrations.
Fatigue : Cyclic stresses are developed due to fluids in parts of the pump, this result in bending
moments on shafts. Also, corrosion assisted fatigue occurs due changes in surface texture of
parts, this increases local stresses and finally crack formation takes place.
Source [9] : A review of major centrifugal pump failure modes with application to the water supply and sewerage
industries Kristoffer K. McKee, Gareth Forbes, Ilyas Mazhar, Rodney Entwistle and Ian Howard Curtin University, Western
Australia

18. 18
Centrifugal Pump - Hydraulic Failures
1. Erosion
2. Noise
3. Vibrations
Cavitation
The wake flow found at the
impeller outlet is one of the
strongest sources of pulsation.
Pressure Pulsation
Lead to alternating stresses and
excessive vibration beyond the
endurance limit of the system
Reference - [6]
Source:https://encrypted-tbn0.gstatic.com/
Negative pressure becomes equal
to vapour pressure & boiling of
water occurs.

19. 19
Centrifugal Pump - Hydraulic Failures
Axial Thrust
Recirculation is the flow of some
fluid around the impeller to the
suction side
Suction Recirculation
Increase in heat, reduction in total
flow thus reduction in pump
efficiency
Axial thrust is imposed along the
shaft axis due to dynamic load
as water is colliding
Can impose excessive stresses,
leading to metal fatigue &
bearing failure Reference - [6]
Source:https://www.sintechpumps.com//axial-thrust-problems.jpg

20. 20
References
[1] “A review of major centrifugal pump failure modes with application to the water supply and sewerage industries”, Kristoffer K.
McKee et al.
[2] Josifovic, Aleksandar & Corney, Jonathan & Davies, Bruce. (2014). “Modeling a variable speed drive for Centrifugal.” 1218-1223.
10.1109/AIM.2014.6878248.
[3] 3 rd International Conference on Energy and Environment CIEM2007, Bucharest, 22-23 November ARRANGING DISSIMILAR
CENTRIFUGAL PUMPS IN SERIES AND PARALLEL
[4] McKee, Kristoffer and Forbes, Gareth and Mazhar, Ilyas and Entwistle, Rodney and Howard, Ian. 2011. A review of major
centrifugal pump failure modes with application to the water supply and sewerage industries, in Asset Management Council
(ed), ICOMS Asset Management Conference, May 16 2011. Gold Coast, QLD, Australia: Asset Management Council.

21. 21
External Links
1. Progressive Cavity Pumps - A concise description of progressive cavity pump operation from the Food and Agriculture Organization
2. Positive Displacement Pumps - https://youtu.be/4OJTN0M1DBk (A video demonstrating types of PD pumps)
3. Lecture on Positive Displacement Pump by Dr. Shibayan Sarkar Department of Mechanical Engg Indian Institute of Technology (ISM), Dhanbad
( https://www.iitism.ac.in/~shibayan/MMC%2016101%20Fluid%20Machines/MMC%2016101_Positive%20Displacement%20Pump_01.pdf )
4. https://www.sciencedirect.com/topics/engineering/positive-displacement-pumps
5. Positive Displacement Pumps by Joe Evans, Ph.D - http://www.pumped101.com
6.Pump Chart Basics Explained - Pump curve HVACR https://www.youtube.com/watch?v=U8iWNaDuUek
7. How to read a pump performance curve- https://allpumps.com.au/how-to-read-a-pumps-performance-curve/.
8. Everything you need to know about NPSH and some things you didn’t-Larry Bachus.

22. Thanks You!
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