This document summarizes a CFD analysis of a centrifugal pump. The objectives were to analyze the pump at different flow conditions, plot characteristic curves, and analyze cavitation. The analysis used ANSYS Fluent and CFX to model the solid pump components with over 19 million mesh elements. Boundary conditions were applied to simulate flow rates from 22 to 34 kg/s. Results showed maximum efficiency of 89.24% occurring at the design flow rate, and lower efficiency under cavitation due to higher power needs to pump vapor. Pressure and velocity plots as well as performance curves matched published literature values.

1. CCFFDD AANNAALLYYSSIISS OOFF
CCEENNTTRRIIFFUUGGAALL PPUUMMPP
By: Dipak Pandey 10BME025
Pavan Patel 10BME031
Pujan Shah 10BME039
Guided By: Prof. S.V. Jain

2. OOuuttlliinnee ooff PPrreesseennttaattiioonn
• Introduction
• Objectives of Present Studies
• Solid and Fluid Model
• Meshing
• Result and Discussion
• Grid In-dependency
• Cavitation Analysis

3. OObbjjeeccttiivvee
• CFD analysis of Centrifugal Pump in pump mode for
different flow conditions in Fluent and Ansys CFX.
• To plot the characteristics curves and compare it with the
model testing results.
• CFD analysis of Centrifugal Pump in pump mode with
cavitation.

4. IInnttrroodduuccttiioonn
Centrifugal Pump
• Due to centrifugal action pressure is developed and it will lift
the fluid to certain height
• It is widely used in industry as well as domestic level

5. CCaavviittaattiioonn iinn ppuummpp
• Cavitation can be define as the breakdown of a liquid
medium under very low pressures into vapour
Phase diagram of water
Pressure plot for impeller section

6. SSppeecciiffiiccaattiioonn ooff PPuummpp
Parameter Value
Rated Head 15 m
Discharge 1500 LPM
Speed 1500 RPM
Power 4.5 kW
Suction flange
dia. 75 mm
Delivery flange
dia. 100 mm
Impeller dia. 250 mm
Type Medium speed, Centrifugal, Volute
casing Pump taken for CFD Analysis

7. (Source- Lubi Pumps)

8. Solid MMooddeell ooff CCaassiinngg aanndd IImmppeelllleerr

9. CCoommppuuttaattiioonnaall DDoommaaiinn

10. MMeesshhiinngg Type Tetrahedral Grid
Spacing 2mm
No. of Elements in Casing 11,55,478
No. of elements in Impeller 8,10,301
Total No. of Elements 19,65,779
Data for mesh of interval 2 mm
Spacing Elements
10 34588
5 178366
3 689111
2.7 942615
2.5 1111607
2 1965779
Mesh of interval 2 mm in Gambit

11. BBoouunnddaarryy CCoonnddiittiioonnss
Boundary Condition
Mass flow (kg/s) Po given (Pa)
22 170000
25 164000
26 162000
28 158000
29 152000
32 130000
34 103000
Performance curves for Pump

12. PPrreessssuurree PPlloottss

13. VVeelloocciittyy PPlloott

14. GGrriidd IInnddeeppeennddeennccyy
Grid Independency
Spacing Elements Max Efficiency Deviation
10 34588 82.63407767 -7.409788226
5 178366 85.44033325 -4.265422058
3 689111 88.20820798 -1.16406104
2.7 942615 89.11992282 -0.142498594
2.5 1111607 88.52044789 -0.81420102
2 1965779 89.24709868 0

15. VVaappoouurr vvoolluummee ffrraaccttiioonn
22 kg/s Part load 29 kg/s BEP 34 kg/s Overload

16. PPrreessssuurree PPlloott CCoommppaarriissoonn

17. PPeerrffoorrmmaannccee CCuurrvveess
Patel and Ramakrishnan [1]

18. PPeerrffoorrmmaannccee CCuurrvveess
Patel and Ramakrishnan [1]

19. PPeerrffoorrmmaannccee CCuurrvveess
Patel and Ramakrishnan [1]

20. CCoonncclluussiioonnss
• For backward curved vanes centrifugal pump increase in mass flow rate Head
decreases, Input and Output power increases
• Efficiency first increases with discharge, reach maximum efficiency at rated
discharge and then decreases
• Input power required in CFD is less than model testing because leakage and
friction loss are not considered.
• Maximum efficiency is found at 0.029 m3/s which is 89.24%.
• In cavitation mode efficiency is 66.95%
• Due to cavitation efficiency of pump reduces because for pumping of vapour
more power is required
• Also due to cavitation head developed by pump is less because vapour has less
density than water

21. RReeffeerreenncceess
1. Patel K and Ramakrishnan N, “CFD Analysis of Mixed
Flow Pump”

22. TThhaannkk YYoouu