Automobile exhaust System

1. SYNOPSIS PRESENTATION
On
STUDY OF AUTOMOBILE
EXHAUST SYSTEM

Project co-
ordinator
MR. Dinesh Dubey
Asst. Prof. (mech)
GROUP
MEMBERS
MAYANK JAGGI
AAQIB JAVED
ALANKRIT VERMA
KARAN THINDH

2. Introduction
•Exhaust gas or flue gases is emitted as a result of the combustion
of fuels such as petrol, diesel or fuel oil.
•A car's exhaust system is responsible for transporting the burned
exhaust, or combustion gases, from its engine and out through the
tail pipe.
•An exhaust system is usually tubing used to guide reaction exhaust
gases away from a controlled combustion inside an engine . The
entire system conveys burnt gases from the engine and includes
one or more exhaust pipes, depending on the overall system
design.

3. Components of exhaust system

The exhaust system may essentially consist of the following components:
•Exhaust Manifold
•Exhaust Pipes
•Catalytic Converter
•Muffler
•The Tail Pipe

4. Components

5. Exhaust Manifold
An Exhaust Manifold is the upper end of the
exhaust system.
•It is attached directly to the side of the engine
and is the first part of the exhaust system to
receive the burned exhaust gases from the car's
engine.
• The exhaust manifold burns any fuel that was
inadequately burned by the engine and funnels
it down into the main exhaust system.
•Due to high temperatures, Excellent oxidation
resistance, High-temperature strength, Thermal
fatigue properties are required.

6. Exhaust Pipes
•The exhaust pipes are
responsible for transporting the
burned exhaust gases from the
engine and the exhaust manifold
and funneling them towards the
car's tailpipe.
•It can be metal or aluminum.
•The pipes are used to create an
effectively sealed pathway.

7. TYPES OF PIPES
There are basically two types:

■
Regular pipe

■
Flexible pipe
Regular exhaust pipe is solid, typically available in straight lengths,
bent configurations and elbows.
Flexible exhaust pipe is flexible enough to bend with road
conditions and accommodate thermal expansion of the system.
The exhaust system may be sealed by welding joints or using
exhaust clamps as a simple, effective way to seal overlapping
pipes.

8. Catalytic Converter
A catalytic converter is a device that
uses a catalyst to convert three
harmful compounds in car exhaust
into harmless compounds.
•Hydrocarbons - in the form of
unburned gasoline.
•Carbon monoxide -formed by the
combustion of
gasoline.
•Nitrogen oxides - created when the
heat in the engine forces nitrogen in
the air to combine with oxygen .

9. Different Catalysts
There are two different types of
catalyst at work
• Reduction Catalyst - first stage
It uses platinum and rhodium to help
reduce the NOx emissions.
Example
2NO => N2 + O2 or 2NO2 => N2 +
2O2
•Oxidation Catalyst -second stage
It uses platinum and palladium to help
reduce the unburned hydrocarbons
and carbon monoxide by burning
(oxidizing) them.
Example
2CO + O2 => 2CO2

10. Pollutants from Car Exhaust
•CO — carbon monoxide. The main source of CO in cities is the internal
combustion engine, where it is produced by incomplete combustion.
•CO2 — carbon dioxide. The internal combustion engine contributes to the
increased concentrations of CO2 in the atmosphere.
•NOx — nitrogen oxide forms when fuels are burned at high temperatures.
•HC — hydrocarbons. Much of the hydrocarbon fuel passes through the
process unconsumed and is expelled into the atmosphere along with other
exhaust fumes.
•Other pollutants such as C6H6 — Benzene and its derivatives and
•SO2 — sulphur dioxide are also present

12. Muffler
•A muffler or silencer is a device for reducing 
the amount of noise emitted by 
the exhaust of an internal combustion 
engine.
•The main muffler absorbs the noise of the 
exhaust gas and is composed of an outer 
shell, inner plates, inner pipes, end plates 
and other components.
•It contains a deceptively simple set of tubes 
that are finely tuned to reflect the sound 
waves produced by an engine so that they 
cancel each other out.

13. Designs of muffler
•Vector Muffler - for larger diesel trucks, uses many concentric 
cones.
•Spiral Baffle Muffler - for regular cars, uses a spiral-shaped 
baffle system.

14. TAIL PIPE
•The tail pipe is end of 
the final length of 
exhaust pipe which 
ends with just a straight 
or angled cut where it 
vents to open air.

15. Importance of exhaust system
The exhaust system has three major functions:
•To channel out the waste products of combustion out of the engine.
•To reduce the noise generated by the engine.
•To clean up the emissions that are harmful to the environment.
•To reduce the pollution and to increase the efficiency of the engine. 

16. REFERENCES
1) “Multi objective Design Optimization of merging configuration
of an exhaust manifold of a car engine” by Masahiro kanazaki
et al.
2) “Market Delivery of ultra-low carbon vehicles in UK” by Ben
Lane.
3) “Low carbon cars by reducing dissipation in hydrogen hybrids”
by Kevin Kendall et al.
4)“Present and Future Trends of Stainless Steel for
AutomotiveExhaust System” by Yoshiharu INOUE and Masao
KIKUCHI submitted in July 2003
5) Automobile engineering by Robert Siegel 2. John R. Howell

17. Thank You