The automobile industry has seen a very rapid growth in the past decade, this is followed by the evolution from ordinary inline cylinder engines to high performance V-type engines, etc., but the parameters which take the centre stage of the competition are efficiency, power, and environmental safety. One technology that is going to be the heart of the future diesel cars is TWIN TURBO technology. The basic principle is derived from the old familiar turbo mechanism. This uses the exhaust from the engine to pressurize the inlet air, thereby providing more oxygen to flow through the combustion chamber, to burn the fuel more efficiently and thus increasing the power output. Unlike the Bi-Turbo mechanism, this Twin Turbo is a combination of two turbo chargers mounted serially rather than in parallel. This configuration offers the car a whopping 112 BHP per litre (1000cc) of engine capacity, which is a world record. And it produces a maximum torque of 400Nm at 1400 RPM. Even though the car delivers a much higher power than its counterparts, it still maintains the conventional 16.5 KMpL as mileage. The environmental safety standard is the major consideration today; this technology is EURO V ready. The only car in India, which has this facility, is Hyundai i20. This technology if properly adopted by the automobile industry could provide a major breakthrough in the Indian commercial car manufacturing.

1. Department of Mechanical
Engineering
K Pavan Kumar,
11781A0347,
IV year, mechanical Dept,
SVCET, Chittoor.
Presented by

2. Twin Turbo Technology

3. Introduction :
The power out put of an engine depends upon the amount of air inducted per unit time
and the degree of utilization of this air , and the thermal efficiency of the engine.
Indicated engine Power
IP=P*L*A*n*K/60000
Where,
IP= indicated power (kW)
P=indicated mean effective pressure(N/m2)
L=length of stroke
A= area of piston
n= no of power stroke, for 2-s engine-N and for 4-s engine N/2, N= rpm
K= No of cylinders

4. Three possible methods utilized to increase the air
consumption of an engine are as follows:
Increasing the piston displacement: This increases the size and
weight of the engine, and introduces additional cooling
problems.
Running the engine at higher speeds: This results in increased
mechanical friction losses and imposes greater inertia stresses
on engine parts.
Increasing the density of the charge: This allows a greater mass
of the charge to be inducted into the same volume.

5. Definition
The most efficient method of increasing the power of an engine is by
supercharging, i.e. increasing the flow of air into the engine to enable
more fuel to be burnt.
A Supercharger is run by the mechanical drive, powered by engine power .
A turbocharger uses the otherwise unused energy in the exhaust gases to
drive a turbine directly connected by a co-axial shaft to a rotary
compressor in the air intake system.

6. Introduction :
 The parameters which take the centre stage of the competition in car
today are efficiency, power, and environmental safety.
 One technology that is going to be the heart of the future diesel cars is
TWIN TURBO technology.
 Unlike the Bi-Turbo mechanism, this Twin Turbo is a combination of
two turbo chargers mounted serially rather than in parallel.
 The only car in India, which has this facility, is Hyundai i20.

7. Super Charger

8. Turbo Charger( schematic diagram)

9. Need of turbocharger and super
charger
 For ground installations, it is used to produce a gain in the power out
put of the engine.
 For aircraft installations, in addition to produce a gain in the power out
put at sea-level, it also enables the engine to maintain a higher power
out put as altitude is increased.

10. Turbo Charger
 A turbocharger is practically a turbine that is fuel-driven.
 A turbocharger, often called a turbo, is a small radial fan pump driven
by the energy of the exhaust flow of an engine.
 A turbocharger consists of a turbine and a compressor on a shared axle.
 The turbocharger increases the pressure at the point where air is
entering the cylinder, a greater mass of air (oxygen) will be forced in as
the inlet manifold pressure increases.

11. Working principle of a turbocharger:
 A turbocharger is a small radial fan pump driven by the energy of the
exhaust gases of an engine.
 A turbocharger consists of a turbine and a compressor on a shared
shaft.
 The turbine converts exhaust to rotational force, which is in turn used
to drive the compressor.
 The compressor draws in ambient air and pumps it in to the intake
manifold at increased pressure, resulting in a greater mass of air
entering the cylinders on each intake stroke.

12. Where the turbocharger is located in the
car

13. 0
2
3
4
1
Four-stroke cycle of an SI engine equipped with a
supercharger turbocharger, plotted on p-v coordinates.
Thermodynamic analysis of turbocharged engine
cycle

14. Net work output Wnet= work done by piston + Gas exchange work
= area A + area
Area A=
Area B= work done by turbocharger=
Wnet = Work done per unit of air mass.
Where, p0 = atmospheric pressure,
p1= pressure after compression,
T0= atmospheric air temperature,
V1= volume of boosted air,
rp =pressure ratio,
r = compression ratio, cp=Specific heat of air
and η = turbocharger efficiency,

15. Selection process of turbocharger
Illustration of the concept of a turbocharger.
•Compressor air inlet,Point1- p1, T1
•Compressor air out let, point2-p2, T2
•Turbine exhaust gas inlet, point 3-
p3,T3
•Turbine exhaust gas outlet-
P4, T4

16.  The compressor efficiency = ( theoretical temperature rise across the
compressor)/(the actual temperature rise). ec is always less than 1.0.
 The turbine efficiency = ( the actual temperature drop across the
turbine )/(the theoretical temperature drop). The turbine efficiency is
also always less than 1.0.

17. The mechanical efficiency of the turbocharger

18. Types of Turbo Chargers
 Single Turbo Charger
 Twin – Turbo Charger

19. Single Turbo Charger
 Single Turbo, a single turbo
requires all 8 cylinders in
order to build some boost.
 Produces good results for drag
racing, which needs extremely
high power.

20. Single Turbo Charger
 Single turbo engines are easier
to set up.
 There are super large single
setups that can support up to
1500BHP, can create real
power but there is that
unwanted lag.
 Doesn't take up much space in
the car.

21. Twin-Turbo Charger
 The secret behind "twin-turbo" is
the clever two-stage forced
aspiration principle.
 The revolutionary twin-turbo
technology, the next big step
forward in the development of
modern diesel engines for
passenger cars.

22. Twin-Turbo Charger
 The car with the Twin-Turbo mechanism gives more power, more torque,
better mileage, and a comprehensive pollution free engine than its rivals.

23. ENGINE SPEED BELOW 1800 RPM:
 By using a small high-pressure turbocharger for the first
stage, the engine responds readily to the gas pedal at lower
speeds without suffering from "turbo lag".
 Up to 1800 rpm this high-pressure turbocharger works
alone and compresses the intake air at up to 3.2 bar boost
pressure.

24. ENGINE SPEED BETWEEN 1800 -
3000 RPM:
 Between 1800 and 3000 rpm, a larger low pressure turbocharger joins
in - both turbines run together in this engine speed range.
 The exhaust from the cylinder will drive the first turbo charger and
come to the second. This will leads to the working of the second stage
turbo charger it affects in the intake air. This intake air which is needed
for the combustion is sucked in and goes to the first stage turbo charger
which will pressurized the air and goes to the cylinders.

25. ENGINE SPEED ABOVE 3000 RPM:
 Above 3000 rpm, only the larger turbocharger continues to deliver
charge air to the cylinders.
 The complex control of both chargers is via a valve in the engine's
exhaust system, controlled by engine speed and load.

26. POTENTIAL OF THE TWIN TURBO-
CHARGER
 The enormous potential of a twin-turbo engine can be seen
from the mean effective pressure values it achieves.
 Whereas traditional turbo-diesels have a mean effective
pressure of 17 to 19 bars, the 1.9-litre twin-turbo reaches
26 bars.

27. EFFICIENCY: 212 hp from 1.9-liter engine with fuel consumption of only 6.0
l/100 km
 Compared with a naturally aspirated diesel engine, power outputs can
be raised by up to 50 percentages without increasing fuel consumption.
 Alternatively, consumption can be reduced by as much as a quarter
without loss of power.
 This high-tech engine delivers a peak power output of 156 kW (212 hp)
from just 1.9 litters displacement.

28.  With this engine the Vectra OPC accelerates from 0 to 100 in 6.5 seconds;
the top speed is an electronically regulated 250 km/h.
 At 6.0 litters per 100 km in the European test cycle

29. Vectra OPC

30. Type of Twin-Turbo
 After the revolution of the two-stage turbo-charger, there are two ways in
which the turbo-charger can be mounted. They are parallel and
sequential.

31. Parallel:

32. Sequential:

33. APPLICATIONS:
 Everybody knows mechanical superchargers are good for low-end output but
short of efficiency at high rev, while exhaust turbochargers works strongly at
high rev but reluctantly at low rev. For decades engineers dreamed of
combining supercharger and turbocharger together. This was tried once in
history – the 1985 Lancia Delta S4 rally car.

34. 1985 Lancia Delta S4 rally car

35. APPLICATIONS:
 In 2005, Volkswagen finally introduced a production unit to
its Golf 1.4 TSI. Called "Twin charger" system.

36. APPLICATIONS:
 The only car in India, which has this facility, is Hyundai i20.

37. Advantages
 The environmental safety standard is the major consideration today, this
technology is EURO V ready.
 Even though the car delivers a much higher power than its counterparts, it still
maintains the conventional 16.5 KMpL as mileage.
 At 1500 rpm, both chargers contribute about the same boost pressure, with a
total of 2.5 bars. (If the turbocharger works alone, it can only provide 1.3 bars
at the same rev.)
 In the 1.4-litre Golf, the Twin charger system produces 170 horsepower and
177 lbft of torque. That's equivalent to a 2.3-litre normally aspirated engine
but it consumes 20% less fuel.

38. Advantages
 The more increase the pressure of the intake air above the local atmospheric
pressure (boost), the more power the engine produces. Automotive
superchargers for street use typically produce a maximum boost pressure
between 0.33 to 1.0 bar, providing a proportionate increase in power.
 Engines burn air and fuel at an ideal (stoichiometric) ratio of about 14.7:1,
which means that if you burn more air, you must also burn more fuel.
 This is particularly useful at high altitudes: thinner air has less oxygen, reducing
power by around 3% per 1,000 feet above sea level, but a supercharger can
compensate for that loss, pressurizing the intake charge to something close to
sea level pressure.

39. Disadvantages
 Cost and complexity
 Detonation
 Parasitic losses
 Space
 Turbo lag

40. CONCLUSION:
 From this, it is clear that the vehicle, which use this
advanced technology, has proved to be more efficient and
more powerful. So let’s hope that the recent automobile will
use this technology and gets modernized.