Intake system-and-supercharger

hi, I am sujon I just completed graduate at International University of Business Agriculture and Technology in Bangladesh Department of Mechanical Engineering

1. PRESENTATION PRESENTATION
ON ON
INTAKE INTAKE
SYSTEM & SYSTEM &
SUPPER SUPPER
CHARGERCHARGER
1

2. Group Members
Name ID
Md Sujon Babu 15207019
MIR. NAZMUL ISLAM 12107140
MD. ALAL MIA 13107043
MD. JIKRUL ISLAM 14207022
YUSUF AHMED 14307031
MD. MAMUN Mia 15207010
RASHIDUL ISLAM 15207012
K.M NAZMUL SHAKIB 15207013
MD. ARIFUL ISLAM 15207016
MD. REAZUL ISLAM 15207026
MAHMUDUL HASAN 15207043
2

3. Table of contents
Introduction
What is intake system ?
Components
Carbureted intake system
Principle
Components of carburetor
Types of carburetor
Throttle body intake system
Supercharger
Basic parts of supercharger
Types of supercharger
Supercharger Terminology
 Method of Supercharging
Supercharging system
Advantages and limitations
Comparison between natural aspirated and supercharged engine
Question answer session

4. Introduction
An intake system is a set of components that essentially
allows an internal combustion engine to inhale, in the same
way that the exhaust system allows it to exhale.
Early automotive intake systems were simply inlets that
allowed air to pass unimpeded into the carburetor, but
modern systems are much more complex.
Modern naturally-aspirated intakes consist of at least four
basic elements (an intake manifold, an air filter, a mass air
flow sensor, and a throttle body), but they still perform the
same basic function that simple air inlets did in early
automobiles.
Other intakes include components like turbochargers and
superchargers to increase engine power.
4

5. Intake system
The system that allows
air and fuel into the
engine is known as the
intake system. This
system is comprised of
the air filter, the intake
manifold, and either a
carburetor or a throttle
body along with
pressurized fuel
injectors depending on
the engine.
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6. Components
The intake system of an internal combustion engine
consist of following components
oAir filter
oIntake manifold
oIntake valve
oCarburetor or Throttle body
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7. Air filter
■The combustion air
filter prevents abrasive
particulate matter from
entering the
engine's cylinders, where it
would cause mechanical
wear and oil contamination.
Most fuel injected
vehicles use a pleated
paper filter element in the
form of a flat panel.
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8. ■ Most fuel injected vehicle use a pleated-paper filter element in
the form of a flat panel. This filter is usually placed inside a
plastic box connected to the throttle body with duct work.
■Older vehicles that use carburetors or throttle body fuel injection
typically use a cylindrical air filter, usually a few inches high and
between 6 inches (150mm) and 16 inches (410mm) in diameter.
This is positioned above the carburetor and the throttle body,
usually in a metal or a plastic container which may incorporate
ducting to provide cool and/or warm inlet air, and secured with a
metal or plastic lid. The overall unit is called the air cleaner.
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9. Intake manifold
■One of the most intriguing
components of the internal
combustion engine is the
intake manifold.
■Responsible for the even
distribution of the air/fuel
mixture to each cylinder,
the intake manifold also
serves as a mount for the
carburetors (on older engines)
and fuel injectors (on modern
engines).
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10. Intake Manifold Construction Materials
Most intake manifolds are cast
from either aluminum or iron.
Cast iron was the metal of choice
throughout most of the 20th
century.
Aluminum has gained in
popularity due primarily to the
fact that it weighs a lot less. With
that in mind.
some intake manifolds are
actually made out of lightweight
composites to further reduce the
weight of the components.
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11. Carburetor
Carburetor is the most
complex part of the entire
system. Carburetors greatly
vary in construction, but they
all operate the same way.
Their job is to supply the
correct mixture of fuel and air
to the cylinder in response to
varying conditions.
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12. Throttle body
■A throttle body is a butterfly 
valve located between the air 
intake  filter  and  the  intake 
manifold.  It  regulates  how 
much  air  can  go  into  the 
engine, based on driver input 
through  the  gas  pedal.  As 
more  air  flows  into  the 
engine, it injects more fuel, 
thus allowing for more power
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13. Carbureted intake system
The carburetor works  on  Bernoulli's principle:  The 
faster air moves, the lower its static pressure, and the 
higher its dynamic pressure. The throttle (accelerator) 
linkage does not directly control the flow of liquid fuel.
Carburetor has two swiveling valves above and below 
the venturi. At the top, there's a valve called the choke 
that regulates how much air can flow in. If the choke is 
closed, less air flows down through the pipe and the 
venturi sucks in more fuel, so the engine gets a fuel-rich 
mixture.
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14. Essential Parts of carburetor are:
• Choke and throttle
• Fuel strainer
• Float chamber
•Venture
• Fuel discharge nozzle
• Float
• Float pivot
• Fuel metering orifice
• Idling adjustment
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15. The Simple Carburetor may be of following
three types
1.Side draught carburetor : It has more width and mounting of 
oil bath air filter is clumsy.
2.Up draught carburetors : In this, the air enters the carburetor 
at the bottom and leaves at the top.
3.Down draught carburetor : In this, air enters the carburetor 
at the top and leaves at the bottom. 
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16. Carbureted intake system
In carbureted engines, fresh air enters the engine through the air filter, 
whose purpose is to filter out particles that could damage the engine. 
From  the  air  filter,  the  fresh  air  is  ducted  into  the  carburetor.  The 
carburetor works on a venture principle whereby the air being drawn 
through accelerates through a narrowed passage called the venture. As the 
passage begins to widen again, a vacuum occurs. It is this vacuum that 
draws fuel into the moving column of air through the carburetor's jets. 
The jets are sized to permit a fairly exact amount of fuel to be drawn into 
the air stream, thus creating the proper mixture of air and fuel.
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17. Throttle body intake system
■A modern fuel injected engine has no carburetor. Instead, it relies 
on  pressurized  fuel  injectors  that  are  triggered  electronically  to 
squirt  just  the  right  amount  of  fuel  into  the  air  stream.  The 
electronic controls can better meter the exact amount of fuel needed 
to make the engine work efficiently.
■A throttle is used to control the amount of air into the engine. 
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18. A typical throttle body consists of a one- or two-piece metal 
casing that has a large bore passing through the middle of it. 
This bore is partially or fully blocked by a component known 
as a throttle valve.
 This component sometimes include additional valves or paths 
for air to flow called idle air control valve and a throttle 
position sensor.
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19. Throttle  position  sensor  that  detects  the  throttle  valve  opening. 
Throttle control motor that opens and closes the throttle valve, and a 
return spring that returns the throttle valve to a fixed position. 
The throttle motor employs a DC motor. The engine ECU controls 
the  amount  and  direction  of  the  current  flowing  to  the  throttle 
control motor, turns or holds the motor, and opens and closes the 
throttle valve via the reduction gear. 
The actual throttle valve opening is detected by the throttle position 
sensor, and this is fed back to the engine ECU. When current is not 
flowing to the motor, the return spring opens the valve to a fixed 
position.
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20. Supercharger
 A supercharger is an air compressor that increases the 
pressure or density of air supplied to an internal combustion 
engine. This gives each intake cycle of the engine more 
oxygen, letting it burn more fuel and do more work, thus 
increasing  power.  Power  for  the  supercharger  can  be 
provided mechanically by means of a belt, gear, shaft, or 
chain connected to the engine's crankshaft.
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21. Parts of supercharger
There are 4 basic parts of supercharger:
1.Drive gear
2.Driven Impeller gear
3.Internal Oil Gear
4.Pulley
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22. ■Gear-driven supercharger : A  supercharger  or  an  air  compressor 
driven by gears from  the crankshaft  of a reciprocating engine. The 
engine  drives  the  supercharger,  and  the  power  increase  more  than 
compensates for any power loss. Gear-driven superchargers are less 
efficient than turbochargers.
■Pulley : The supercharger pulley is used to spin the supercharger, which 
in turn compresses air into the combustion chambers in the cylinders. 
Think of it as a pump that pushes air into the intake manifold. The 
greater  the  speed  of  the  pump,  the  more  air  can  be  compressed. 
Therefore,  having  a  high  performance  pulley  and  blower  parts  can 
greatly improve the vehicle's performance. The smaller the pulley, the 
faster the shaft can spin and create even faster speeds.
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23. TYPES OF SUPERCHARGERS
There are two main types of superchargers defined according
to the method of gas transfer:
•positive displacement
•dynamic compressors.
■Positive displacement blowers and compressors deliver an
almost constant level of pressure increase at all engine
speeds (RPM).
■Dynamic compressors do not deliver pressure at low
speeds; above a threshold speed, pressure increases with
engine speed.
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24. TYPES OF SUPERCHARGERS (cont.)
■Two major types of positive displacement
superchargers are:
1.Roots Supercharger
2.Vane Supercharger
■One example of Dynamic compressor is
Centrifugal Supercharger.
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25. Roots Supercharger
•The roots-type supercharger is called a positive displacement
design because all of the air that enters is forced through the
unit.
■As the meshing lobes spin, air trapped in the pockets between
the lobes is carried between the fill side and the discharge side.
Large quantities of air move into the intake manifold and "stack
up" to create positive pressure.
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26. Vane Supercharger
A number of vanes are mounted on the drum of the supercharger. These
vanes are pushed outwards via pre-compressed springs. This arrangement
helps the vane to stay in contact with the inner surface of the body.
Now due to eccentric rotation, the space between two vanes is more at the
inlet & less at the outlet. In this way, the quantity of air which enters at the
inlet decreases it’s volume on its way to outlet. A decrease in volume
results in increment of pressure of air. Thus the mixture obtained at the
outlet is at higher pressure than at the inlet.
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27. Centrifugal Supercharger
A centrifugal supercharger powers an impeller -- a device similar to a rotor
-- at very high speeds to quickly draw air into a small compressor housing.
As the air is drawn in at the hub of the impeller, centrifugal force causes it
to radiate outward.
The air leaves the impeller at high speed, but low pressure. A diffuser -- a
set of stationary vanes that surround the impeller -- converts the high-
speed, low-pressure air to low-speed, high-pressure air. Air molecules slow
down when they hit the vanes, which reduces the velocity of the airflow
and increases pressure.
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28. Supercharger Terminology
■Volumetric efficiency: The efficiency and effectiveness
with which an engine cylinder is filled with air; for
example, if an engine cylinder filled completely with air
on the intake stroke, it would have a volumetric efficiency
of 100 percent. A supercharger packs engine cylinders
with greater-than-100 percent volumetric efficiency.
■Static compression ratio: The compression ratio that is
built into your naturally aspirated engine.
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29. Supercharger Terminology (cont.)
■Effective compression ratio: The approximate
compression ratio when boost pressure is combined with
static compression ratio. This is important in calculating
safe boost levels for an engine.
■Detonation: Spontaneous combustion of leftover air/fuel
mixture in the engine cylinders, most likely due to
increased heat and (boost) pressure. Detonation in forced
induction can cause serious engine damage and should be
avoided at all cost.
■Rotors and Impellers: Internal supercharger mechanisms
within the supercharger that compress air. Rotors are
found on Roots and screw-type superchargers; impellers
are typically found on centrifugal blowers.
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30. Method of Supercharging
Compression Drive by engine.
 Compression Drive by turbine.
 Compression Drive by external source of power.
Compression Drive by ct engine shaft and free
turbine.
Direct compiling between engine compressor and
turbine.
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31. Compressor driven by engine
In this arrangement, the compressor is driven by engine with help
of gearing or belt drive, a certain engine output is used to run the
compressor as shown in fig. In this case, net output of
supercharged engine is greater than gross output of naturally
aspirated engine. The net output increase due to supercharging is
obtained by subtracting this power from the gross output. Air
cooler is used after compressor to reduce the temperature of air:
therefore, further density of air is increased.
31

32. Compressor driven by turbine
In this arrangement, the compressor is driven by turbine
which run with help of exhaust gases coming from engine as
shown in fig. In this case engine output is not utilized to drive
to drive the compressor, but the exhaust energy of the engine
is used to run the turbine which is coupled to compressor.
There is no mechanical connection between engine and
supercharger.
32

33. Compressor driven by external source of power
In this arrangement, the compressor is neither driven by
engine nor turbine, but compressor is separately driven by
external power.
33

34. Compressor driven by shaft and free turbine
In this arrangement, power produced by engine is
utilized only to run the compressor as shown in fig. the
exhaust gases coming from engine is utilized to run the
turbine. The power produced by turbine is used for
external load.
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35. Direct coupling between engine,
compressor and turbine
In this arrangement, the compressor, engine and turbine all
are coupled together with help of gearing as shown in fig.
In this case, If the turbine output is not enough to run the
compressor during the part load on engine power takes care
of the remaining load of compressor. In addition to this an
extra power from the turbine can be fed to the engine.
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36. Supercharging system
Supercharging increase intake by compressing air above
atmospheric pressure, without creating a vacuum. This
forces more air into the engine, providing a "boost." With
the additional air in the boost, more fuel can be added to
the charge, and the power of the engine is increased.
Supercharging adds an average of 46 percent more
horsepower and 31 percent more torque.
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37. Supercharging system (cont.)
37

38. Advantages of supercharging
■Higher power output. This was whole point of studying
& installing superchargers.
■Reduced smoke from exhaust gases. The extra air pushed
into cylinder, helps the air to complete combust leading
to lesser smoke generation.
■Quicker acceleration of vehicle. Supercharger starts
working as soon as the engine starts running. This way
the engine gets a boost even at the beginning leading to
quicker acceleration.
■Cheaper than turbocharger.
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39. Limitations
■Draws power from engine: Though the overall mechanical
efficiency is increased but it consumes power from the
engine. The same job is done by a turbocharger without
consuming extra power !
■Increased heat generation: The engine should have proper
heat dissipation systems as well as it should be able to
withstand thermal stresses !
■Induces stress: The engine must hold up against the high
pressure & bigger explosions generated in the cylinder. If
the engine is not designed considering these stresses, it may
damage the piston head.
39

40. natural aspirated engine vs.
supercharged engine
■ A naturally aspirated engine takes in air to mix with fuel
and create combustion on its own. Supercharged engines
use some kind of compressor to force additional air into
the engine.
■Naturally Aspirated Engines do not employs any
supercharger or turbocharger thus they are lighter but
their volumetric efficiency is low and thus specific power
output is not as good as that of supercharged engine.
Usually high performance engines are supercharged or
turbocharged.
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