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Venkatarao et al, International Journal of Advanced Engineering Research and Studies E-ISSN2249–8974

IJAERS/Vol. II/ Issue I/Oct.-Dec.,2012/46-49

Research Paper

DESIGN AND ANALYSIS OF THE IMPELLER OF A

TURBOCHARGER FOR A DIESEL ENGINE V.R.S.M. Kishore Ajjarapu

1, K. V.P.P.Chandu

2 D.M.Mohanthy Babu

3

Address for Correspondence 1PG Student,

2Assistant Professor, Department of Mechanical Engineering, SIR C.R.R. College of Engineering,

Eluru-534007,West Godavari Dist, A.P 3Chief Manager Hindustan Shipyard Limited, Vishakhapatnam

ABSTRACT The objective of this paper is to be design the impeller of a turbocharger for a diesel engine to increase its power and

efficiency, and showing the advantage of designing (six blade compressor ,twelve blade turbine) comparing with the (eight

blade compressor ,eleven blade turbine) of a turbocharger. An investigation in to usage of new materials is required. In the

present work impeller was designed with three different materials. The investigation can be done by using CATIA and

ANSYS software. The CATIA is used for modeling the impeller and analysis is done in ANSYS .ANSYS is dedicated finite

element package used for determining the variation of stresses, strains and deformation across profile of the impeller.

An attempt has been made to investigate the effect of temperature, pressure and induced stresses on the impeller. By

identifying the true design feature, the extended service life and long term stability is assured. A structural analysis has been

carried out to investigate the stresses, strains and displacements of the impeller. A modal analysis has been carried out to

investigate the frequency and deflection of the impeller. A thermal analysis has been carried out to investigate the total heat

flux and direction heat flux.

An attempt is also made to suggest the best material for an impeller of a turbocharger by comparing the results obtained for

three different materials (wrought aluminum alloy 2011, incoloy alloy 909, wrought aluminum copper alloy for compressor

and inconel alloy 740, inconel alloy 783, wrought aluminum alloy 2219 for turbine impeller. Based on the results best

material is recommended for the impeller of a turbocharger.

KEYWORDS: Design; Analysis; Diesel Engine; Turbocharger

1.0 INTRODUCTION

Turbochargers are a class of turbo machinery

intended to increase the power of internal

Combustion engines. This is accomplished by

increasing the pressure of intake air, allowing more

fuel to be combusted. In the late 19th century,

Rudolf Diesel and Gottlieb Daimler experimented

with pre-compressing air to increase the power output

and fuel efficiency. The first exhaust gas

turbocharger was completed in 1925 by the Swiss

engineer Alfred Buchi who introduced a prototype to

increase the power of a diesel engine by a reported

40%. The idea of turbo charging at that time was not

widely accepted. However, in the last few decades, it

has become essential in almost all diesel engines with

the exception of very small diesel engines. Their

limited use in gasoline engines has also resulted in a

substantial boost in power output and efficiency.

Their total design, as in other turbo machines,

involves several analyses including: mechanical,

aerodynamic, thermal, and acoustic. Engineers and

researchers still seek ways to improve their designs

while governed by rules of cost and manufacturing

capabilities. At first, scientists simply attempted to

develop the conceptual designs into reliable products

for end users. These turbochargers were very large

and were mostly destined for marine applications.

Because of this, their studies were based on the

output performance of the turbochargers with focus

on the thermodynamics of the process. Although

rotor dynamic analysis is now an important part of

the design process, a thorough rotor dynamic

investigation was then very difficult and relatively

few studies were published. By 1938, the first

turbocharged automobile engine was manufactured

by “Swiss Machine Works Saurer”. Turbocharged

automobiles were plagued by reliability issues and

with some spectacular failures like the Chevrolet

Corvair (last made in 1963), turbocharged engines

had essentially been removed from the market.

Turbocharged engines made a comeback during the

oil shortage in the early 70’s due to their inherent

increase in fuel efficiency.

The advances in rotor dynamic analysis using up-to-

date computation technology have made the

dynamics of a turbocharger’s rotor-bearing system a

rich area for investigation. Vendors are now looking

for more dynamically stable turbochargers to benefit

business and increase customer satisfaction. More

contributions are needed to have optimum design

stability, while assuring continued low cost

production.

They also require a high level of reliability and

efficiency in order to be cost-effective. There are

several ways to reduce the price of turbochargers; the

easiest way is to keep the design as simple as

possible. A common design assembly in an

automotive turbocharger consists of a simple inboard

bearing mounting arrangement with a radial outflow

compressor and a radial inflow turbine on a single

shaft.

2.0 ANALYSIS OF AN IMPELLER

For Compressor impeller 3 materials investigation is

done using structural analysis and modal analysis

For turbine impeller 3 materials investigation is done

using structural analysis, modal analysis and thermal

analysis.

The variation of von mises stress, Von mises strain,

and deformation for three different materials of

compressor impellers, using structural analysis Table .1: Structural analysis for compressor impeller



Figure.1: Wrought aluminum alloy 2011 Von mises

stress

Figure.2: Incoloy alloy 909 Von mises stress

Figure.3: Wrought aluminum copper alloy 2014 von

mises stress

The variation of frequency and deflection for three

different materials of compressor impeller using

modal analysis. Table.2: Modal analysis for compressor impeller

Figure.4: Wrought aluminum alloy 2011 frequency

deflection

Figure.5: Incoloy alloy 909 frequency deflection

Figure.6: Wrought aluminum copper alloy 2014

frequency deflection

The variation of von mises stress, Von mises strain,

and deformation for three different materials of

turbine impeller, using structural analysis. Table.3:Structural analysis for turbine impeller

Figure.7: Structural analysis for turbine impeller

Figure.8:Inconel alloy 740 von mises stress

Figure.9: Inconel alloy 783 von mises stress

Figure.10: Wrought aluminum alloy 2219 von mises

stress

The variation of frequency and deflection for three

different materials of turbine impeller using modal

analysis.



Table .4: Modal analysis for turbine impeller

The variation of total heat flux and direction heat flux

for three different materials of turbine impeller Table .5: Thermal analysis for turbine impeller

Figure.11: Thermal analysis for turbine impeller

Figure.12: Inconel alloy 740 Total heat flux

Figure.13: Inconel alloy 783 total heat flux

Figure.14: Wrought aluminum alloy 2219 total heat flux

3.0 RESULTS AND DISCUSSIONS

3.1 Compressor

3.1.1 Effect of von mises stresses on compressor

impeller materials

The comparison of von mises stresses with respect to

compressor materials .the maximum von mises

stresses are induced in wrought aluminum copper

alloy 2014,when compared to the wrought aluminum

alloy 2011 and incoloy alloy 909.where a maximum

value of von mises stresses 49.294 Mpa was noticed

to wrought aluminium copper alloy 2014 and

minimum value of von mises stresses 32.981 MPA

was noticed for incoloy alloy 909.

3.1.2 Effect of von mises strain on compressor

impeller materials

Von mises strain with respect to compressor

materials. It can be seen that the maximum von mises

strain are induced in wrought aluminium alloy

2011.when compared to the incoloy alloy 909 and

wrought aluminium copper alloy 2014. Where

maximum value of von mises strain 0.0005967 mm

was noticed for wrought aluminium alloy 2011 and

minimum value of von mises strain 0.00020743 mm

was noticed for incoloy alloy 909

3.1.3 Effect of displacement of the compressor

materials

Comparison of displacement with respect to

compressor materials. It can be seen that the

maximum displacement are induced in wrought

aluminium alloy 2011.when compared with incoloy

alloy 909 and wrought aluminium copper alloy

2014.where a maximum value of displacement

0.1226 mm was noticed to wrought aluminium alloy

2011,and minimum value of displacement 0.013233

mm was noticed to incoloy alloy 909

3.2 Turbine

3.2.1 Effect of von mises stresses on turbine

material

The Comparison of von mises stresses with respect

to turbine materials. It can be seen that the maximum

von mises stresses are induced in inconel alloy 783.

when compared with inconel alloy 740 and wrought

aluminium alloy 2219 . Where a maximum value of

von mises stresses 283.7 Mpa was noticed for inconel

alloy 783 and minimum value 171.01Mpa was

noticed for inconel alloy 740.

3.2.2 Effect of von mises strain on turbine

material

The comparison of von mises strain with respect to

turbine materials. it can be seen that the maximum

von mises strain are induced in inconel alloy 740

when compared with inconel alloy 783 and wrought

aluminium alloy 2219. Where a maximum value of

von mises strain 0.002443 mm was noticed for

inconel alloy 740 and minimum value 0.0009749 mm

was noticed for wrought aluminium alloy 2219.

3.2.3 Effect of displacement of turbine materials

The comparison of displacement with respect to

turbine materials .it can be seen that the maximum

displacement are induced in inconel alloy 740 when

compared with inconel alloy 783 and wrought

aluminium alloy 2219.when a maximum value of

displacement 0.35753 mm was noticed for inconel

alloy 783 and minimum value 0.12693 mm was

noticed for wrought aluminium alloy 2219.

3.2.4 Effect of total heat flux on turbine impeller

The total heat flux of a turbine impeller on three

different materials .the maximum total heat flux

occurred in wrought aluminum alloy 2219 and the

value is 11.773 w/mm2,the minimum total heat flux

occurred in inconel alloy 740 and the value is

0.70635 w/mm2.



4.0 CONCLUSION For Compressor the minimum von mises stress

(32.981 MPA) is obtained for the material incoloy

alloy 909.And the maximum frequency (482.61 HZ)

is obtained for the material incoloy alloy 909.For

Turbine the minimum von mises stress (171.01

MPA) is obtained for the material inconel alloy

740.And in the frequency comparing to the

compressor maximum frequency (482.61 HZ ) for

incoloy alloy 909. And the turbine three materials

frequencies inconel alloy 740 - (773.58 HZ ) ;

inconel alloy 783- (679.12 HZ) ; wrought aluminum

alloy 2219 – (887.16 HZ) ; are more than compressor

maximum frequency (482.61 HZ) . so that the

compressor material is withstand up to the (482.61

HZ) with the minimum stress (32.981 MPA) for the

compressor material incoloy alloy 909 and the

turbine material is withstand up to the (773.58 HZ)

with the minimum stress (171.01 MPA) for the

turbine material inconel alloy 740.

REFERENCES 1. Watson, N. and Janota, M. S., 1982, Turbocharging the

Internal Combustion Engine, Wiley,New York. 2. Gunter, E. G. and Chen, W. J., 2005, “Dynamic

Analysis of a Turbocharger in Floating Bushing

Bearings,” Proc. 3rd International Symposium on Stability Control of Rotating Machinery, Cleveland,

OH.

3. Gunter, E. G. and Chen, W. J., 2000, DyRoBeS© - Dynamics of Rotor Bearing Systems User’s Manual,

RODYN Vibration Analysis, Inc., Charlottesville, VA. 4. Holmes, R., Brennan, M. J. and Gottrand, B., 2004,

“Vibration of an Automotive Turbocharger – A Case

Study,” Proc. 8th International Conference on Vibrations in Rotating Machinery, Swansea, UK, pp.

445-450.

5. Kirk, R. G., 1980, “Stability and Damped Critical Speeds: How to Calculate and Interpret the Results,”

Compressed Air and Gas Institute Technical Digest,

12(2), pp. 1-14.

6. Alsaeed, A. A., 2005, “Dynamic Stability Evaluation of

an Automotive Turbocharger Rotor- Bearing System,”

M.S. Thesis, Virginia Tech Libraries, Blacksburg, VA.

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