enhancing performance of domestic centrifugal pump … issn: 2347-1697 international journal of...

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Available online through - http://ijifr.com/searchjournal.aspx Accepted After Review On: October 27, 2015

Published On: October 30, 2015

International Journal of Informative & Futuristic Research

ISSN: 2347-1697 Volume 3 Issue 2 October 2015

Abstract

An impeller is a rotating component of a centrifugal pump, usually made of iron, steel, bronze, brass, aluminium or plastic, which transfers energy from the motor that drives the pump to the fluid being pumped by accelerating the fluid outwards from the center of rotation. The velocity achieved by the impeller transfers into pressure when the outward movement of the fluid is confined by the pump casing. Impeller have various dimensions like inner diameter, outer diameter, inlet vane angle, outer vane angle, thickness etc. so it is more cost consuming through trial and error method of experiment. CFD analysis is solution for this problem. In this paper proposed impeller model is constructed through 3-D software CATIA V5. Then it is meshed in hyper mesh software and analysis done in CFD software. The pressure and velocity distribution is obtained and head is calculated.

1. Introduction

A centrifugal pump consists of a set of rotating vanes, called impeller, enclosed within a stationary

housing called a casing. Water is forced into the center (eye) of the impeller by atmospheric or

other pressure and set into rotation by the impeller vanes. The resulting centrifugal force accelerates

the fluid outward between the vanes until it is thrown from the periphery of the impeller into the

casing. The casing collects the liquid, converts a portion of its velocity energy into pressure energy

and directs the fluid to the pump outlet. Computational Fluid Dynamics (CFD) is a computer-based

tool for simulating the behavior of systems involving fluid flow, heat transfer, and other related

Enhancing Performance Of Domestic

Centrifugal Pump By Use Of CFD Tool

By Changing Design Parameters Paper ID IJIFR/ V3/ E2/ 059 Page No. 579-590 Research Area CFD Analysis

Key Words Centrifugal Pump, Computational Fluid Dynamics (CFD) Impeller Design,

3-D Software CATIA V5, Pump Assembly, Meshing, ANSYS Fluent Solver

1st Satish M. Rajmane

Research Scholar

WIT Research Center,

Solapur University, Maharashtra, India

2nd

Dr. S. P. Kallurkar

Principal,

Atharva College of Engineering,

Mumbai-Maharashtra, India

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ISSN: 2347-1697 International Journal of Informative & Futuristic Research (IJIFR)

Volume - 3, Issue -2, October 2015 Continuous 26th Edition, Page No.:579-590

Satish M. Rajmane, Dr. S. P. Kallurkar:: Enhancing Performance Of Domestic Centrifugal Pump By Use Of CFD Tool By Changing Design Parameters

physical processes. It works by solving the equations of fluid flow (in a special form) over a region

of interest, with specified (known) conditions on the boundary of that region. Essentially there are

three methods for determine the solution to flow problems viz. Experimental, Analytical and

Numerical. The Analytical methods aim at getting a closed form solution in the entire domain

assuming the process to follow continuum hypothesis. These are generally restricted to simple

geometry, simple physics and generally linear problems. Experimental techniques have their

inherent problems viz. that they are equipment oriented, and they need large resources of hardware,

time and operating costs. Their applications are also limited due to scaling considerations. Further

theses involve certain measurement difficulties and handling of large quantity of data. Numerical

methods have emerged as a third method and have overcome the restrictions in both experimental

and analytical methods.

2. Pump Specifications

2.1. Existing Pump Specification The systematic research on the influence of the various design

aspects of a centrifugal pump in its performance at various flow rates requires numerical

predictions and experiments. The specifications of existing centrifugal pump undertaken in the

current analysis are shown in Table No1.

Table -1: The specifications of existing centrifugal pump

Sr No Description Specification

1 Impeller inner diameter 58mm

2 Impeller outer diameter 170mm

3 No. of vanes 6

4 Vane inlet angles 25° and 30°

5 Thickness of impeller flanges 5mm

6 Head 24m

7 Speed 2780rpm

2.2. Proposed Pump Specification During current analysis some parameter of pump are

modified and modeling of that impeller are done in CATIA software. The specifications of

proposed centrifugal pump are shown in Table No. 2.

Table - 2: Specifications of proposed centrifugal pump

3. Meshing Of Proposed Design

Sr No Description Specification

1 Impeller inner diameter 60mm

2 Impeller outer diameter 150mm

3 No. of vanes 6

4 Vane inlet angles 26° and 32°

5 Vane outlet angle 30°

6 Thickness of impeller flanges 5mm

7 Speed 2780rpm

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The model is prepared in CATIA V5 is imported to new pre-processing software called

HYPERMESH for entering the boundary conditions and for tetrahedral meshing of the given

geometry. Element Size of meshing is 5. The following diagram shows a impeller with casing

meshed geometry.

Figure 1: Meshing of pump assembly

Table-3: Mesh Details

Meshing Type 3D

Type of Element Tetrahedral

No of Nodes 84272

No of Elements 396789

4. Simulation Of Proposed Centrifugal Pump

After meshing of the model of pump assembly commercial CFD code CFX is used for simulation

of the pump performance. The boundary conditions are applied. The performance results are

obtained at different mass flow rate conditions with same speed by taking turbulent modeling. The

numerical simulation is checked to detect the pressure at inlet and outlet of centrifugal pump and to

get safe range of operating at different mass flow rate and operating speed

For solving we are using ANSYS Fluent Solver. In this interface following parameters used:

System type: Pressure Based system

Analysis type: Steady state condition

Model: k-epsilon (2 equations) with realizable model

Fluid Used: Water

Mass flow rate at inlet: 4 kg/s, 5kg/s, 6kg/s.

Temperature: 300C.

4.1 Pressure Plots Of Proposed Design

Figure no 2 to 7 shows that pressure plot in Pascal. At inlet is more and decreases as gradually

along the length. Color strip shows indicate the different pressure level. Blue color indicates the

minimum pressure level and red color indicate the max pressure level.

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Figure 2: Pressure plot for 4kg/s of inlet angle 26°


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4.2 Velocity Plots Of Proposed Design

Velocity plots shown in figure no 8 to 13. Color strip shows the different velocity levels in

geometry. Velocity for different mass flow rate is as shown in the following figure

Figure 8: Velocity plot for 4kg/s of inlet angle 26°


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5. Results

Here we will discuss different head at different inlet blade angle with different mass flow rate. The

head of the centrifugal pump can be increased by number of ways such as modifying the geometry

of the pump, increasing the diameter of the impeller, increasing number of blades, inlet blade angle,

outlet blade angle etc.

5.1 For inlet angle 26° and outlet angle 30°

In analysis we get pressure plot and velocity plot. From pressure plot we get pressure at inlet and

pressure at outlet. From that we can calculate head as follows.

5.1.1 For mass flow rate 4kg/s:-

Fig 2 shows pressure distribution at inlet and outlet of pump as follows.

Pressure at inlet= 297618 Pa

Pressure at outlet= 1295.27 Pa

H = 30.20619 m.




Pressure at outlet= 1018.1Pa

H = 29.01365m





H = 24.46496 m.

5.2 For inlet angle 32° and outlet angle 30°





H = 32.8621 m.





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H = 30.4328 m.





H = 30.3785 m.

The comparison between head of different inlet angle with different mass flow rate can be very well

represented in a tabular format, as shown in Table no 4.

Table 4: Head at different mass flow rate

6. Conclusion

Head of existing pump is 24m while head of proposed pump is 32m calculated in results.

The pressure heads for different vane angle is tabulated.

Increase of the designed flow rate causes a reduction in the total head of the pump.

Low pressure is generated at leading edge of the blade.

The formation of cavitations on the blade is increasing with the increase of mass flow rate.

Performance results show that total static head is the function of the mass flow rate with

constant operating speed.

The results obtained from the experiments showed a reasonable increase pressure head.

7. References

[1] Hudson Daniel Raj.E and Kalaimani.T “Investigation of Key Impeller Parameters of Centrifugal

Pump Using CFD” , International Journal of Engineering Research & Technology (IJERT) Vol. 2

Issue 10, October – 2013.

[2] S.Rajendran and Dr.K.Purushothaman “Analysis of a centrifugal pump impeller using ANSYS-

CFX”, International Journal of Engineering Research & Technology (IJERT) Vol. 1 Issue 3, May –

2012

[3] .Ashish J. Patel1, Bhaumik B. Patel2, “Design and Flow through CFD Analysis Of Enclosed

Impeller”, International Journal of Engineering Research & Technology (IJERT), Vol. 3 Issue 7,

July – 2014, ISSN: 2278-0181

[4] J. Anagnostopoulos, “CFD Analysis and design effects in a radial pump impeller”, WSEAS

Transactions on Fluid Mechanics, vol. 1 (7), pp. 763-770, 2006.

[5] R. Ragoth Singh1, M. Nataraj2.” World Journal of Modeling and Simulation Vol. 10 (2014) No. 2,

ISSN 1 746-7233, England, UK, pp. 152-160. “Design and analysis of pump impeller using SWFS”

Inlet angle P1 P2 Δp Head

26°

297618 1295.27 296323 30.2062

285642 1018.1 284624 29.0136

241257 1255.7 240001 24.465

32°

323317 939.9 322377 32.8621

299659 1113.5 298546 30.4328

299482 1468.5 298014 30.3785

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Authors Biography:

1st .S. M. Rajmane is having ME from Solapur University. He is Research

Scholar for WIT Research Center, Solapur University, Solapur. He is having

more than 10 years teaching experience. His area of interest is in Fluid

machinery, FEM, Design engineering.

2nd

. Dr. S. P. Kallurkar is having PhD from NITIE Mumbai. Presently

working as Principal in Atharva College of Engineering, Mumbai. He is

Research Guide at WIT Research Center, Solapur University, Solapur. He is

having more than 25 years teaching experience.

enhancing performance of domestic centrifugal pump … issn: 2347-1697 international journal of...

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