EXHAUST SYSTEM
OF
VEHICLES
Dr. M.R.SWAMINATHAN
Assistant Professor
I.C. Engines Lab
Anna University, Chennai
NEED FOR EXHAUST
• The exhaust system
• Collects
• Cleans
• Quiets
the exhaust gas from the engine
EXHAUST SYSTEM COMPONENTS
• Exhaust Manifold
• Engine pipe
• Connector pipe
• Catalytic converter
• Intermediate pipe
• Clamp
• Muffler
• Muffler hanger
• Resonator
• Tail pipe
EXHAUST SYSTEM
• The exhaust components are supported along the
length of the vehicle by brackets suspended from
the under body.
• These are usually rubber-mounted supports that
help isolate the vibrations of the exhaust from the
main body of the vehicle.
• Rubber is preferred because of its natural
dampening effect
• The engine pipe is attached to the
exhaust manifold
• It takes the gases away through the
catalytic converter,
• then through the muffler system to
the outside environment
• The exhaust manifold is bolted to the
engine's cylinder head.
• It can be of a one-piece or two-piece
construction.
• In performance type vehicles, the exhaust
manifold is often replaced with extractors.
• A normal exhaust manifold is usually
made from cast iron.
• Due to the extreme temperatures
generated at the exhaust manifold,
heat shields can be installed to
protect other vehicle components
from heat damage
CATALYTIC CONVERTER
• The catalytic converter is attached
to the engine pipe, between the
engine and the muffler.
• It converts the harmful by-products
of combustion to relatively harmless
gases
MUFFLER
• The muffler is located between the engine
and the exhaust outlet
• It is designed to reduce the noise levels of
the exhaust by breaking up the sound
frequencies of the gases.
• Mufflers can be of various designs but their
function is common to all.
• Serve to reduce velocity of exhaust gases by
increasing pressure.
• Reduces noise levels.
• Serves as a spark arrester – needed in high
plant residue environments.
• Two types:
• A) straight through, and B) reverse flow.
MUFFLER TYPES
RESONATOR
Many
manufacturers
use
a
resonator in the exhaust system. It
is located between the muffler and
the exhaust outlet.
Its function is to reduce any
resonance levels that the muffler
could not adequately suppress.
• When a wave hits the hole, part of it continues
into the chamber and part of it is reflected.
• The wave travels through the chamber, hits the
back wall of the muffler and bounces back out of
the hole.
• The length of this chamber is calculated so that
this wave leaves the resonator chamber just
after the next wave reflects off the outside of
the chamber.
• Ideally, the high-pressure part of the wave
that came from the chamber will line up with
the low-pressure part of the wave that was
reflected off the outside of the chamber wall,
and the two waves will cancel each other out
RESONATOR
Variable flow exhaust
• A moveable valve fitted within the
exhaust system is used to change the
amount of exhaust back-pressure.
• At higher engine speeds when exhaust
noise levels are unacceptable the valve
is closed, thus reducing the bore of the
exhaust.
Contd.
This creates greater back-pressure and noise
cancellation is the result. The valve can be
operated by
•
Pneumatics - exhaust gas pressure
•
Electronics - a computer
When a variable flow exhaust is added to the
baffle and chamber system, quieter noise
emissions are the result. This is because the
system can partially respond to changes in engine
speed and load.
ELECTRONIC MUFFLERS
• Any restriction to exhaust flow in the
exhaust system creates back-pressure.
• Whilst some back-pressure can be
beneficial, excessive back-pressure reduces
volumetric efficiency.
• This in turn reduces engine efficiency.
ELECTRONIC MUFFLER
• Electronic mufflers are designed to
produce anti- noise without restricting
exhaust flow.
• This computer-controlled system uses a
microphone to detect the sound waves
produced within the exhaust system.
• As the exhaust gas leaves the tail pipe,
computer driven loudspeakers are
operated to generate the correct
amount of anti-noise.
The result is a virtually silent exhaust
without generating additional and
unwanted back-pressure across all
engine operating conditions.
This increases fuel economy and
reduces exhaust emissions.
CERAMIC COATINGS
• Ceramic coatings are being used as a barrier
between dissimilar metals to reduce friction,
which in turn reduces wear in internal engine
components.
• The most common applications for ceramic
coatings are on the exhaust system, intake
manifolds, and exhaust headers
When ceramic thermal barrier coatings are
applied to exhaust manifolds or headers, they
provide two advantages.
Firstly, they protect the headers from rust and
corrosion; and,
Secondly, they reduce heat loss which can be
translated into high engine output.
If the exhaust headers are internally coated, the
hot exhaust gases travel at a higher velocity with
less turbulence due to smoother surface inside
the system.
• Internally, ceramic-coating the cylinder head's
combustion chamber and exhaust ports has the
effect of creating a faster, hotter burn during the
power stroke and help scavenge gases from the
cylinder at a quicker rate.
• The coating of these passages also assists in
creating a thermal transfer from the hot gases to
the cylinder head itself.
FLEXIBLE TUBE
UNIFIED CONDENSER & RADIATOR
• The fins of the radiator and the condenser have
been integrated into a single sheet, and the
conventional resin tanks have been replaced
with aluminIum tanks, facilitating an integrated
brazing process using the NB method.
• The UCR is an integrated component that
reduces the total parts count compared with the
conventional configuration of having a separate
radiator and condenser.
MUFFLER
SPUN CONVERTER
DIFFERENT DESIGNS OF EXHAUST
EXHAUST GAS RECIRCULATION
EGR VALVE
EXHAUSTEC TECH.
ExhausTEC stands for Exhaust Torque Expansion
Chamber, a technology patented by Bajaj
The technology involves use of a small chamber
connected to the exhaust pipe of the engine to
modify the back-pressure and the swirl
characteristics, with an aim to improve the lowend performance of the bikes.
The ExhausTEC technology is claimed to be highly
effective in improving the low- and mid-range
torque
THANK YOU
FOR
PATIENT HEARING