This document discusses the design and workings of turbochargers. It describes how a turbocharger uses exhaust gases to power a turbine, which spins a shaft connected to the compressor to force more air into the engine. This allows more fuel to be burned, increasing an engine's power without increasing its size. Specific parts of the turbocharger like the turbine, compressor, and wastegate are detailed. An example of an SJ44 turbocharger is provided along with efficiency calculations and references.

1. TURBOCHARGER
Raka K L
0606073474
MECHANICAL ENGINEERING UNIVERSITY OF INDONESIA

2. Turbocharger
Turbocharger - an engine upgrade bolted onto the exhaust manifold that
dramatically increases torque, power, and acceleration.
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3. Turbocharger
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4. Turbocharger Design
Process of the air flow:
http://auto.howstuffworks.com/turbo7.htm

5. WORKING OF TURBOCHARGER
Workings of the Turbocharger:
1. Exhaust waste from the engine cylinder travels towards the
turbocharger.
2. Exhaust waste powers the turbine wheel which is connected to
the compressor wheel by the turbine shaft.
3. Turbine shaft rotates the compressor wheel drawing in and
compressing cool air.
1. Compressed air travels through an intercooler for further
cooling before reaching the engine cylinder.
1. Fuel mixes with the compressed air and is ignited by the spark
plug.
2. Exhaust waste is let out by the combustion and the process
repeats itself (Nice).

6. Detailing Specific Parts
The Turbine:
The turbine wheel begins the whole process of sending
compressed air to the engine cylinder.
Turbine wheels can be made of steel or ceramic blades, but
ceramic is preferred because it is lightweight meaning it will
spin faster and prevent turbo lag.
Turbo lag is the delay that comes from the engine not
responding to the boost acquired from the turbocharger (Nice).
Turbine wheels can rotate anywhere between 80,000 and
150,000 revolutions per minute (RPM) (Nice).
The turbine wheel is connected to the turbine shaft, and the two
are connected by ball bearings or fluid bearings.

7. Detailing Specific Parts
The Turbine:
Proper mounting and connection between the turbine and turbine shaft
is necessary because it operates at such high speeds.
The wastegate releases excess exhaust waste from the turbine.
www.angelfire.com/.../turbo_files/image003.jpg

8. Detailing Specific Parts
Compressor:
When the compressor wheel spins, it draws in air from the ambient air
inlet located on the opposite side of the turbine exhaust gas inlet to
retrieve cool air.
The compressor increases the density of incoming air by six to eight
pounds per square inch (psi).
At sea level, the density of air is 14.7 psi, so the compressor yields
about a fifty percent increase (Nice).
The highly compressed air leaves the compressor section through the
compressor air discharge as it travels towards the intercooler.

9. Detailing Specific Parts
Compressor:
http://auto.howstuffworks.com/turbo4.htm

10. Example of Turbocharger
SJ44 Series Turbocharger
SJ44 series turbocharger suits for 1. 5-2. 0L motor. Its standard characteristics include:
*Centrifugal compressor with wide flow area; *Centripetal turbine;*Dual floating bearing system;
*Single runner symmetry turbine housing;*By-pass valve; Optional characteristics include:*Fixed
section turbine housing of 3-4. 5cm2,*Variable section turbine housing;*Compressor housing
turbine housing inclination can be chosen from 0 from 3600.
Pressure Ratio : 2. 5
Flow Area : 0. 02-0. 11kg/s
Max Rotation Speed : 220000r/min
Power Area : 20-56kw
Horsepower : 27-75kw
Diesel Litres : 1. 9L
Compressor inlet Dia : 34mm
Compressor ourlet Dia : 44mm
Bypass valve:
Cooling Mode:
Size:
Turbine Dia : 42mm
Application:

11. SJ44 Series Turbocharger Efficiency
Calculation
P out
L !
P in
W
m
!U 1
2
W ! U12 m
U 1 !

12. TD1 N
60 !

13. T

14. 0.034

15. 22000
60 ! 391 .5 m/s
W ! U 12 m

16. W ! 391.5 m
s
y 0.065 kg s
2
W ! Pout ! 9.96 v 103Watt
!
¡ out
in
¨ 9.96 v 10 3 ¸
© 51v 10 3 ¹
L !© ¹
ª º
L ! 0.195 ! 19.5%

17. References
Sayers, A.T. Hydraulic an Compressible Flow Turbomachines. McGraw-Hill. New York. 1992
(2003). Turbochargers ± A Process Description. Retrieved February 25, 2006, from
www.angelfire.com/.../turbo_files/image003.jpg
Brain, M. (2006). HowStuffWorks: How Car Engines Work. Retrieved February 24, 2006, from
http://auto.howstuffworks.com/engine4.htm
Graham, A. (2005). Turbochargers boost diesels. Automotive news, 80(6174), 22.
Nice, K. (2006). HowStuffWorks: How Turbochargers Work. Retrieved February 24, 2006, from
http://auto.howstuffworks.com/turbo.htm
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