Modern Technologies in Automobiles
(Hasan Amjad, Muhammad Haseeb Shahzad, Muhammad Hussain & Muhammad Taimoor)
Abstract:
1. Introduction and Background
It began when people realized animals could carry them
from one place to another. As the centuries rolled by, they used this mobility
to expand our horizons. While, at the same time seeking even better ways to travel,
they harnessed the power of steam and began to replace animals with engines but
it was not until the development of the internal combustion engine and the
discovery of tools of oil, deep in the earth that we were able to achieve a
basic improvement in individual transport. In 1886, two vehicles were unveiled
only months apart by German engineers, Karl Benz and Gottlieb Daimler-the
automobile was born. Gottlieb Daimler was the first to see a wide variety of
uses for the gasoline burning internal combustion engine. He tried it first in
a motorcycle, and when that was a success he was ready to install his engine in
a carriage. At the same time Karl Benz, working only 60 miles away was
developing his own vehicle. But while Daimler was installing his engine in a
carriage, Benz was creating the world's first automobile from scratch. It was
successfully driven in late 1885 and patented on January 29th automobile
Daimler's vehicle made its appearance.
The first automobile was manufactured, but still a
much more was needed to be done. The automobiles had to still go through the
decades of evolution. As the time passed by, the challenges for the automobiles
manufacturers were raised. Engineers started working on the ways and
technologies that could surpass the standards, and hence a new era of
technologies was started. Many technologies were introduced that could enhance the
efficiency and working of the systems.
This report briefly presents some of those modern automobile
technologies i.e. Hybrid Technology, CVT system, GDI, EFI, Turbochargers, that
are being used, their need, importance and impact on the system and the
environment.
Modern Technologies
2. Dual Fuel System
 |
Figure 2.1-Modern
dual fuel engine
|
e
|
In Dual fuel system, two fuels
are used together at the same time in a mixture. However, it usually cranks up
on one type of fuel and a governor built in the system is used to gradually
introduce the secondary fuel source until optimal mixture of these two fuels is
achieved for efficient running of the vehicle. Dual fuel system is capable of
operating on one fuel at a time in the absence of other fuel source but in many
dual fuel engines, from the combination only one fuel is capable of starting
the engine. Thus in order to initiate the engine that particular fuel must be
available for consumption.
 |
Figure 2.2-Schematic diagram of Diesel Natural Gas
Engine
|
All
duel fuel systems do not use a diesel-natural gas mixture. Some, such as the
E85 compatible vehicle, consume a mixture of ethanol and gasoline. The optimal
mixture of these fuels is 85 percent ethanol to 15 percent gasoline. Dual-fuel
systems are also used for non-transportation engines, including generators and
drilling rigs. Fewer consumer products use dual-fuel systems because most of
these engines are used in industrial applications and as emergency power back-up
systems.
There is a big difference between
dual fuel system and bi-fuel system. In case of dual fuel system fuel are used
in a mixture but in case of bi-fuel system two fuels are available for
consumption separately. In bi-fuel system, there is switching between two fuels
so that
engines always operate on most efficient fuel according to condition.
engines always operate on most efficient fuel according to condition.
2.1 Working
Reciprocating internal combustion engines are generally
divided in two categories, compression-ignition (CI) and spark-ignition (SI)
engines:
• In CI engines
(diesel engines), air is compressed at pressures and temperatures at which an
easily ignitable fuel fires spontaneously when injected and burns progressively
after ignition.
• Whereas, SI engines (Otto
engines) running according to the Beau de Rochas cycle, the carbureted mixture
of air and gaseous or gasified fuel which does not fire easily (high octane
index), is compressed under its ignition point, then fired at a chosen instant,
by an independent means.
In dual-fuel engines both types
of combustion coexist together, a carbureted mixture of air and high-octane
index gaseous fuel (natural gas) is compressed and then fired by a small liquid
fuel injection which ignites spontaneously at the end of compression phase. The
advantage of this type of engine resides in the fact that it uses the
difference of flammability of two fuels. In case of lack of gaseous fuel, it is
possible to run according to the diesel cycle; switching being possible when
running and without load variation. The disadvantage is the necessity to have
liquid diesel fuel available. Theoretically, the liquid fuel quantity necessary
to fire is tiny (less than 1 %), but, it is not possible to inject with the
given pump and injectors assemblies fuel quantities varying from 1 to 100 %. If
we do not want the material to be doubled, we must be satisfied by injection of
the minimum possible quantity of standard diesel fuel.
 |
Figure 2.3-Schematic Diagram of dual fuel system
|
·
Economic
benefits: As the cost of diesel fuel rising, and
dual-fuel engines considerably decreasing diesel fuel usage, converting an
engine to operate primarily on a cheaper gaseous fuel is economically
attractive. Moreover, spark plugs and an ignition system are not required,
eliminating the costly spark plug maintenance associated with traditional
natural gas engines, which helps to further reduce overall cost of operation.
Depending on the expected number of running hours and the price of diesel and
gaseous fuels, the up-front installation cost of retrofitting an existing
diesel engine to dual-fuel operation can be recovered quickly.
·
Environmental
benefits: Gaseous fuels and
natural gas in particular are much cleaner than diesel. Diesel engines that
have been converted to dual-fuel operation have exhibited significant reduction
in NOX and CO2 over their original diesel operation. This
is more important in areas with increasingly tough emissions regulations. In
addition, on-site diesel storage capacity can be minimized.
·
Technical
benefits: Retrofit systems can be
installed in the field quickly, reducing engine downtime. No modifications are
required to the core engine or to the factory fuel management system. With the
engine’s main fuel becoming gaseous fuel rather than diesel and the electronic
control system maximizing fuel efficiency, installing an alternative fuel
system enables the on-site diesel supply to last much longer, extending engine
uptime without compromising performance.Replacing diesel
fuel with natural gas typically extends engine maintenance intervals and
overall engine life. For example, life expectancy of cylinder-head valve seats
is improved due to the cleaner combustion that gaseous fuel exhibits over
diesel. Benefits of the factory diesel engine, including hardware ruggedness
and operational efficiency, are maintained. Returning to operation on 100%
diesel fuel is possible at any time.
·
Safety: Gasoline or petrol is an easily ignited volatile
fuel. While diesel fuel is less volatile, it presents the same storage and
handling problems. Comparatively, natural gas exhibits many different
characteristics. It is buoyant at temperatures above -160 F, does not pool on
the ground, and dissipates rapidly in the atmosphere. It is nontoxic,
noncorrosive, and environmentally safe.
2.3 Applications of Dual Fuel Engines
Dual fuel natural gas/diesel
engines are becoming popular in many parts of the world. The more expensive,
sophisticated computer control systems are being introduced successfully in
North America and Australia and are being tested in European in anticipation of
market entry. But their use in other parts of the world is expanding,
particularly in Latin America, India, Pakistan, China and other parts of Asia.
They tend to be used in large vehicles such as buses and refuse trucks, but
also have applications in smaller commercial diesel engine vehicles.
2.4 Importance of Dual Fuel Engines Availability
Diesel engines can be converted
as dual fuel natural gas engines relatively easily because typically there are
no changes in the engine compression ratio, cylinder heads, or basic operation
as a diesel cycle engine. Even the sophisticated computer controlled dual fuel
systems are being developed as ‘bolt on’ technologies that can be removed if
necessary, to resell the vehicle as a normal diesel engine. These conversions
are easy to install and easy to maintain. This flexibility makes these engines
very useful in many global markets
3. Hybrid Technology
The increased
awareness that the world’s energy resources are limited has stimulated many
countries to reexamine their energy policies and take measures in eliminating
waste. It has also sparked interest in the scientific community to take a
closer look at the energy conversion devices and devise ways to develop new
techniques to utilize the existing limited resources.
This led to
the development of the most efficient and energy conservation system, Hybrid
System. A hybrid car is one that uses more than one means of power transmission
i.e. combination of an internal combination engine (petrol or diesel engine)
with an electric motor. ("Hybrid Vehicle" 2018)
3.1 Working of Hybrids
Hybrid cars
have a conventional engine (an I.C Engine), an electric motor and a battery.
These automobiles operate either on engine or an electric motor a combination
of both.
 |
Figure 3.1-Schematic Diagram of Hybrid Car
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The above Figure
illustrates the schematic diagram of a hybrid car. There as an engine which
runs on fuel. In addition to the transmission system the engine is also attached with the generator. When
the car is running of the engine, meanwhile the generator produces electricity
and stores in a lithium battery. This battery can then be used to run the car.
Thus, the car has two transmission systems, one which is connected with an
engine and other with the electric battery.
3.2 Types of Hybrids
Based
upon the working the hybrid technology has following sub types ("What Is A
Hybrid Car And Should You Buy One?" 2018)
3.2.1
Parallel Hybrid Cars
3.2.2 Range
Extended Hybrid Cars
3.2.3
Plug-in Hybrids
3.2.1 Parallel hybrid cars
These are the most common type of hybrid. The car’s wheels can be powered
in three different ways:
·
Directly by the
engine
·
By the electric
motor alone
·
Both power
sources working together.
 |
Figure 3.2-Schematic Diagram of Parallel Hybrid
|
Application
Toyota also
uses this system in the Yaris and Auris hatchbacks and Prius+ MPV hybrids.
Similarly, Audi, BMW, Mercedes-Benz, Land Rover, Citroen, Lexus, Peugeot,
Porsche and Volkswagen work on the same basis.
3.2.2 Range extender hybrid cars
·
Use their
conventional engine to produce electricity for a generator that recharges the
batteries
·
The engine does
not drive the car it only charges the batteries.
·
The Car is run
by electric motors.
 |
Figure 3.3-Schematic Diagram of range Extender Hybrid
|
Applications
The BMW i3
with Range Extender is one of the examples. The Honda Jazz Hybrid is another
one.
3.2.3 Plug-in hybrids
·
The type of
hybrid can be plugged into an electric outlet to recharge their batteries,
·
The batteries
can be charged on the move
·
They have a conventional
engine but also have larger batteries than regular hybrids and can drive longer
distances
·
Travel up to 30
miles on electric power alone
 |
Figure 3.4-Schematic Diagram of Plug-in Hybrid
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Applications
There are a growing number of plug-in hybrids on offer, including the
Mistubishi Outlander, Toyota Prius and Volvo V60.
3.3
Advantages:
· Environmentally Friendly:
Produce less emissions and harmful gases that pollute the environment, as
their run on electric supply.
· Less dependence on Fossil Fuels:
A Hybrid car requires less fuel to
run which means less emissions and less dependence on fossil fuels. This in
turn also helps in reduction of the price of gasoline, and decreases our
dependency on these fossil fuels.
· Regenerative Braking System:
Hybrid cars have Regenerative
Braking System i.e. each time brake is applied while driving a hybrid vehicle
recharges battery a little
· Built from Light Materials:
Hybrid cars are made up of lighter
materials which means less energy is consumed to run. The engine is also
smaller, lighter and compact which also saves much energy.
4. Variable Valve Timing (VVT):
The valves in
an internal combustion engine are responsible for controlling the intake and
exhaust gases into and out of the combustion chambers. In other words, valves
are lungs of an Internal Combustion Engine. The timing, duration and lift of
these valves is significant and plays principle role in engine’s performance.
In an engine,
during the intake the piston moves from the TDC to BDC, intake valve open and
air flows into the engine. Then in the compression stroke the intake valve
closes and gas is compressed. During the power stroke the piston moves towards
the BDC. At last, exhaust valve opens and gas is expelled out. But,
in actual case, the valves do
not open/close at dead center positions but open/close at some degree on either
side of the dead centers. The opening of valve occurs earlier and the exhaust
continues even at later crank angles. This is done to draw more air in the
intake stroke and thus increases engine’s performance.
In this case an engine will have a period of "valve
overlap" at the end of the exhaust stroke, when both the intake and
exhaust valves are open. The intake valve opens before the exhaust
gases completely leave the cylinder, and their velocity aids in drawing in
the fresh charge. Engineers aim to close the exhaust valve just as the fresh
charge from the intake valve reaches it, to prevent either loss of fresh charge
or un-scavenged exhaust gas.
 |
Figure 4.1-Valve Timing Diagram
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4.1
Need for Variable Valve Timing
Without variable valve timing, the valve timing would
be the same for all engine speeds and operating conditions. For instance, the
engine running at a higher rpms it
needs to draw more air, but the intake valves may close before enough air has
entered each combustion chamber, reducing performance of the engine. So, a
system must be introduced which could alter valve, depending upon the speed and
operating conditions. An engine equipped with a variable valve timing actuation
system is freed from constraint, which allows performance to be improved over
the engine operating range.
In automobiles, the opening and closing of the valves
is controlled by camshafts. The cams lift the valves for a certain period of time
during each intake and exhaust cycle. The valve timing, relative to the
position of the crankshaft, is important. The camshaft is driven by the
crankshaft through gears, timing belts or chains. ("Variable Valve
Timing" 2018)
4.2 Valve Timing Terminologies
4.2.1
Valve Timing: At
what time during the engine’s working, the valve will open
4.2.2
Valve Duration: For
how long the valve will open
4.2.3
Valve Lift: How
much valve will move above valve seat
4.3 Methods for implementing Variable Valve Timing
4.2.1 Cam switching
·
Uses two cam
profiles, with an actuator to swap between the profiles (at a specific engine
speed).
·
Provides
variable valve lift and variable duration.
The drawback
is adjustment is discrete rather than continuous.
Application
Honda's VTEC system. VTEC
changes hydraulic pressure to actuate a pin that locks the high lift, high
duration rocker arm to an adjacent low lift, low duration rocker arm(s).
 |
Figure 4.2-Cam Switching
|
4.2.2 Cam phasing
·
Most common
used method for implementing Variable Valve Timing.
·
Uses a device
called variator which allows continuous adjustment of the cam timing
The draw back
of the system is that the duration and lift cannot be adjusted.
 |
Figure 4.3-Cam Phasing
|
Applications
Mostly automobile’s
manufacturers use this method of VVT.
4.2.3 Oscillating cam
·
Uses an
oscillating or rocking motion in a part cam lobe, which acts on a follower.
·
Follower then
opens and closes the valve.
·
Some
oscillating cam systems use a conventional cam lobe, while others use an
eccentric cam lobe and a connecting rod.
·
The major
advantage is adjustment of lift and duration is continuous.
In these
systems, lift is proportional to duration, so lift and duration cannot be
separately adjusted.
 |
Figure 4.4-Oscillating Cam
|
Applications
The BMW
(valvetronic), Nissan (VVEL), and Toyota (valvematic) oscillating cam systems
act on the intake valves only.
4.2.4 Eccentric cam drive
·
Eccentric cam
drive systems operate through an eccentric
disc mechanism
·
The mechanism
slows and speeds up the angular speed of the cam lobe during its rotation.
·
The advantage
of this system is that duration can be varied independent of lift.
The drawback
is two eccentric drives and controllers are needed for each cylinder, which
increases complexity and cost.
Applications
MG Rover is
the only manufacturer that has released engines using this system.
 |
| Figure 4.5-Eccentric Cam |
5. Exhaust gas recirculation (EGR) system:
5.1 Background:
In case of complete combustion in
an internal combustion (IC) engine the only products which will be expelled out
from exhaust are water vapors and carbon dioxide. Both of these products are
harmless. CO2 is an inert gas and is not directly harmful to human
beings. In reality, air-fuel mixture does not burn completely and incomplete
combustion generates several harmful products (i.e. pollutants). Nitrogen oxide
(NOX) is one of these pollutants. Prolonged exposure of these oxides
of nitrogen is dangerous to health. Nitrogen and oxygen react at very high
temperature. High peak temperature and availability of oxygen in the engine
cylinder are main cause of NOX formation. In the present of oxygen inside the
combustion chamber at high combustion temperatures the following chemical
reactions will takes place behind the flame. ("Exhaust Gas
Recirculation" 2018)
N2 + O2 >
N2
+ 2H2O >
Balanced chemical equations show that a significant
amount of NO will be formed at the end of combustion. The majority of NO
produced will however decompose at the low temperatures of exhaust. But, due to
very low rate of reaction at the exhaust temperature, a part of NO formed
remains in exhaust. The NO formation will be less in rich mixtures than in lean
mixtures. The concentration of oxides of nitrogen in the exhaust is closely
related peak combustion temperature inside the combustion chamber.
In order to control the amount of NOX
forming during combustion oxygen content resent in the cylinder and temperature
of the cylinder should be reduced. There are number of ways to do so. Among
these one method is to introduce an inert gas or non-combustible substance in
the engine cylinder which will perform dual function. It will take some space
in the cylinder volume and thus less amount of air (oxygen) will come inside
the cylinder during intake stroke. Secondly, it will absorb some of the heat
produced during the combustion. Reduction in two main reasons of nitrogen
oxides formation limits the amount of NOX formed. The following method is used for reducing peak cycle
temperature and thereby reducing NOX emission.
5.2 Exhaust gas Re circulation:
 |
| Figure 5.1-Schematic diagram of EGR (www.yanmar.com) |
In the internal combustion engines, exhaust gas recirculation (EGR) system is basically a simple method of reducing Nitrogen Oxides (NOX). This system recirculates some of the exhaust gases back to the Engine cylinder. These exhaust gases dilute O2 incoming air stream and include some inert gases which can absorb excessive heat generated in the engine cylinder, thus limiting the peak in-cylinder temperatures. At low temperature NOX are not produced in the engine cylinder.
Exhaust gases re-circulated to
the engine should be 5-15% only in the total intake volume. This maximum
quantity is limited by the need to sustain continuous flame during combustion. Excessive EGR in poorly set up applications can cause
misfires and partial burns.
5.2.1 Cooling system for Exhaust Gas Recirculation:
|
The exhaust gas drawn off for recirculation has a temperature of around 650 degrees Celsius. It is therefore far too hot to be fed directly into the cylinders; it would increase the temperature of the combustion chamber even further, thereby defeating its actual purpose — that of reducing nitrogen oxide formation by lowering the combustion temperature. For this reason, the exhaust gas is first cooled to around 120 degrees Celsius.
5.3 Effect of EGR on NOX and HC formation
Exhaust gas recirculation system
limits the amount of NOX by lowering the temperature of the engine.
While performing its function EGR system deposits more carbon (C) content due
to reduction in oxygen intake. These effects are clearly shown in fig (2).
|
From the graph it is concluded that as the percentage of EGR
increases nitrogen oxide formation reduces and formation of Carbon content in
the engine increases.
5.4 Advantages of EGR:
·
NOX
formation reduces.
·
Reduction in
cylinder temperature improves the engine lifetime (especially exhaust valve
life).
·
There is potential
reduction of throttling losses on spark ignition engines at part load.
6. Continuously Variable Transmission (CVT):
6.1 Background:
In automobiles power is generated
by the engine and available at the crank shaft for usage. Problem is that we
cannot supply power generated directly from source engine to the wheels because
we need to alter speed and torque of the vehicle. Initially, we need high
torque but low speed to start the automobile but as the vehicle continue its
journey we need to switch from low speed to high speed of vehicle and less
torque. Thus we need a system which will enable us to perform this function,
such a system is called is called transmission system. Basic job of
transmission system is switching between high and low speeds, and corresponding
torque.
Transmission system is simply
refers to as gearbox which consists of gears and gear trains in order to
accomplish the conversion of speed and torque from rotating power source to
other device. When an automobile starts, engine rotates at very high speed.
This high speed is inappropriate for starting, stopping and slower travel. Transmission
limits this high speed to the low speed increasing torque in the process by
altering the gear number.
In transmission system, there are certain numbers of gears which can be switched in order to perform its job. Switching of gears can be done manually or automatically. In case of manual transmission system there is driver operated clutch which is engaged or disengaged by foot pedal in automobiles and thus regulates torque transfer from engine to transmission, and gear selector operated by hand. Schematic diagram of Manual transmission system is shown in fig (4).
 |
| Figure 6.1- Schematic diagram of Manual transmission system (www.pakwheels.com) |
Main disadvantage of manual
system is that for every gear change, jerk is felt. Driving in bumper-to-bumper
traffic in large cities can be both a nuisance and a wallet-breaker if you own
a manual transmission. Those familiar with driving a manual transmission in
urban areas often complain about leg cramps and increased workload when driving
in traffic. With a third pedal to actuate during shifts, a manual transmission
can quickly become annoying. Automatic transmissions are considerably easier
and more convenient to drive in stop-and-go traffic.
6.2 CVT:
 |
| Figure 6.2-Engine connected with CVT (www.audiworld.com) |
6.3 Working of CVT:
 |
| Figure 6.3-variation in pulley diameter (practicalmotoring.com.au |
 |
| Figure 6.4-Schematic diagram of CVT |
This is the same thing a conventional transmission does,
but instead of changing the ratio in stages by shifting gears, the CVT
continuously varies the ratio -- hence its name
6.3.1 Effect of CVT on vehicle speed and fuel
consumption:
 | |
|
 |
| Figure 6.6-variation in speed for CVT and General AT (www.quora.com) |
In case of manual transmission system gears are to be changed alternatively,
thus at every gear change there is decrement of speed and then increment which
causes inconvenient. In auto transmission although there is no need to change
gears manually but a jerk is felt during gear change due to fluctuation in
engine speed. Following Figures shows comparison between CVT
and Auto/Manual transmissions
CVT not only improves speed variation over time but also it makes automobile fuel efficient. An automobile having CVT consumes less fuel than manual transmission system. This is because, in CVT there are not number of gears mounted on shaft rather pulley-belt arrangement is present which offers less frictional effects and thus less fuel is consumed. Comparison is shown below for CVT and Manual systems over years.
 |
| Figure 6.7: Fuel Consumption for CVT and Manual systems |
7. GDI (Gasoline Direct Fuel Injection)
It is a Fuel injection system in
which gasoline is directly injected into the cylinder of a gasoline automobile
engine. Usually we know that gasoline is injected into the engine after mixing
it with air in carburetor.
 |
| Figure 7.1- Fuel injection system using GDI |
7.1 Working of GDI
Gasoline
engines work by sucking a mixture of gasoline and air into a
cylinder, compressing it with a piston, and igniting it with a spark. The
resulting explosion drives the piston downwards, producing power. This
conventional sort of system has some drawbacks as well which are being
discussed in section. Therefore, some modifications in the fuel injection
system of gasoline automobile system was made and gasoline direct injector was
introduced. In this system the gasoline is directly injected into t6he engine
while compressed air is drawn either by supercharging, by turbocharging or
using any air induction method.
After filtering the fuel from
the fuel filter the pressure of the fuel must be raised. This is being done by
a fuel pump which is connected to the ECU (Engine control unit). The
pressurized fuel is now ready to be pumped into the engine via an electrically
operated fuel injector.Schematic diagram of GDI system is shown
 |
| Add caption |
7.2 Need of GDI system:
●
At low speed or while cranking, the mixture supplied by a
carburetor is not much enriched so it
will not ignite properly and for its enrichment, at such conditions some
arrangement in the carburetor was required.
●
Atmospheric pressure can change the working of carburetor because
at different atmospheric pressures the amount of air entering the carburetor
may vary.
●
It gives the proper mixture at only one engine speed and load,
therefore, suitable only for engines running at constant speed.
●
Maintenance costs of carburetor are higher (Mechstuff4u.com. (2018)).
Above
mentioned problems can be solved by using Gasoline direct injector system which
controls emission level, improves the fuel consumption efficiency of engine and
increase the power output of the automobile.
7.3 Comparison between GDI system and Carburetor:
7.3.1
Speed vs. Power output:
The speed vs. power output curves
of engines with carburetor and with GDI system have been shown below:
7.3.2 Speed vs. Power output: |
7.3.3
Speed vs. Fuel consumption Graph:
|
||||
|
|
7.4 Advantages of GDI system:
7.4.1 Power Output
With
the exception of some high end modified vehicles, fuel injection usually offers
a much better power output and performance than a standard carburetor-based
vehicle.
7.4.2 Fuel Efficiency
Because
fuel injection is usually controlled by a vehicle's electronic control unit or
car computer, fuel consumption is usually managed much better than with a
carburetor. It almost always results in better fuel efficiency.
7.4.3 Emissions Performance
With
better fuel efficiency comes better emissions performance. Fuel injected
vehicles produce far fewer carbon based emissions than vehicles with
carburetors.
7.4.4 Ability to Accommodate Alternative Fuels
Vehicles
that use direct fuel injection are better equipped to handle alternative fuels,
and fuels with additives that are designed to help keep your car engine clean.
7.4.5 Drivability and Smooth Operation
Vehicles
that use fuel injection rather than a carburetor usually drive much smoother,
because fuel flow is better managed and more consistent.
7.4.6 Diagnostic Capability
Because
direct injection is regulated by your car's computer, problems with fuel
injection can easily be diagnosed with a simple computer diagnostic test
7.5 Automobiles using GDI technology:
●
Sport car 9
●
In 1955, launch of Mercedes 300 SL with direct
injection.
●
First serial application with 4 stroke engine.
●
1996: First stratified gasoline direct injection
on Mitsubishi Galant
●
1998: Toyota D4
●
1999: Renault IDE (Lambda 1 with high EGR rate)
●
2000: First Bosch gasoline direct injection VW «
FSI » engine
●
2000: PSA HPI engine
●
2005: PSA Prince engine THP
●
The Audi R8 4.2l FSI gained the victory in 2001
of the famous race “24 heures du Mans” with the gasoline direct injection
technology.
8. EFI (Electronic Fuel Injection) System
Fuel injection is defined
as the introduction of fuel in the automotive engine by the means of a fuel
injector. Fuel injectors are mechanically operated as well as electronically
operated. Mechanically operated fuel injectors have some disadvantages. In 1967,
first serial application of the indirect injection controlled by electronics
(VW 1600). By the introduction of electronic control system in automobiles, the
problems of emissions and fuel wastage has been reduced (2018. Jalopnik.Com.
https://jalopnik.com/how-electronic-fuel-injection-works-499902815).
8.1 Functions:
It
can be considered as the brain of the automobile. Engine Control Unit (ECU) performs four
basic operations in the smooth running of an automobile:
●
ECU controls the fuel
mixture.
●
ECU controls idle speed.
●
ECU is responsible for
ignition timing
●
ECU controls valve
timing.
8.2 Working:
ECU
can be considered as a black box. Several receivers and sensors collect data
for ECU and there is a microprocessor which is actually the part of ECU which
processes the data provided by the various sensors then it sends the
information to actuators. Following fig
It
can be seen form fig that there are several sensors like oxygen sensor, Air
temperature sensor, Engine temperature sensor, MAP sensor and other receivers
and sensors are there. Similarly there are some actuators which are performing
useful work. All sensors and actuators are linked by a microprocessor.
Microprocessor receives data from the sensors and then gives instructions to various
actuators to perform useful work.
 |
| Figure 8.1: showing schematic diagram of ECU |
8.3 Disadvantages of Mechanical fuel injection system:
Mechanical
fuel injectors are operated on the principal that pressurized fluid exerts
pressure on the valve to open it. They have the limitation on delivering
optimal fuel to the engine. Their
incompetency to provide optimum amount of fuel is due to the fact that these
injectors are affected by following parameters:
●
Engine’s speed and
●
Load
●
Atmospheric and engine temperatures
●
Altitude
●
Ignition timing
.
 |
Figure 8.2-Relation between A/F and RPM
|
 |
| Figure 8.3-Power vs. Rpm relation |
9. Turbocharging
Turbocharging is an important process through which
sufficient air is forced in the cylinder of an engine. It is a forced induction systems. It provides air to
the engine which produces more power as the volumetric efficiency of the
engine.
9.1 Turbocharger:
It is a forced
induction system which forces the incoming air of the atmosphere by the push
provided by the outgoing exhaust gases. It is actually a turbine based forced induction part
of the automobile engine that increases the efficiency of the engine.
 |
| Figure 9.1-Turbocharger |
9.1.1 Need of turbocharger:
As we know that the efficiency of engine depends upon
the volumetric efficiency of the engine. The volumetric efficiency of the
engine can be increased using multiple solutions.
We
can use following means to achieve our goal:
●
By ducting intake air from outside of the engine
compartment
●
By changing the time for which the valves opens
●
By supercharging
●
By turbocharging
All the above-mentioned methods except turbocharging
does not give efficient system (Ezez. 2018).
They can maintain the system to some extent but they are not much effective
ways therefore the invention of turbocharger took place. We can have volumetric
efficiency close to 100%.
 |
| Figure 9.2-Efficiency of various automobile engines |
9.1.2 Parts:
Turbocharger
consists of following parts:
●
Compressor
●
Turbine
●
Control system
●
Bearing system
 |
| Figure 9.3-Schematic diagram of Turbocharger |
9.1.3 Working:
The
spindle of turbo charger is attached with two wheels one is compressor wheel
and the other one is the turbine wheel. When outgoing air is passed through the
turbine wheel it makes the spindle rotate and the compressor wheel forced the
incoming air to come into the cylinder.
9.1.4
Advantages of Turbocharger:
9.1.5
Future work:
In
future we are looking for the replacement of gasoline with some other fuels. In
some countries gasoline has been partially been replaced by ethanol but all
over the world gasoline is still a fuel which is being used in excess. The
following graph sows the consumption of ethanol in US.
 |
| Figure 9.5-Production of carbon dioxide through various sources |
We want to replace gasoline because of a number of factors.Gasoline increases the emission rate of CO2.The following graph clearly shows this claim.
Oil
and Gasoline Are Not the Only Things Causing Climate Change, but They Are Among
the Biggest.
Other
improvements in fuel systems are as follows:
- Fuel Pump Relays
- Modern Fuel Pumps,
Filters, and Regulators
- Pulse-Modulated Fuel
Pumps
- Fuel Delivery System
Sensors
- Fuel System
Diagnostics ("Modern Fuel Delivery Systems - Know Your Parts".
2018)
10. Latest Research in Automobiles
In this section the research review of two research papers
is being presented.The research paper, which we have
studied regarding our thermodynamic Project are
International
Journal of Engineering Research and Technology.
ISSN
0974-3154 Volume 6, Number 3 (2013), pp. 343-350
©
International Research Publication House
http://www.irphouse.com
In
this paper researcher highlights the technical aspects and the working of the
advanced technologies used in the present or can be used in the future
automobiles. The technologies that are discussed in this paper are Variable
valve timing, Valve-electronic Engines , Downsizing and Turbocharging, Advanced
Combustion Modes, Hybrid/Electric
Vehicles, Fuel Cells, Weight Reduction Materials, Alternative Fuels, Batteries
and Energy Storage, 42 volt system, Drive by wire Technology, Camless engine,
Exhaust gas recirculation, Sterling engine opposed piston engine, Split cycle
engine, Free piston engine and Wankel rotary engine
A critical analysis with the
advantages and disadvantages of these technologies are made in the paper. A
final conclusion is drawn that once these technologies are in the market they
will not only help in providing better modes of transport but will also help in
reducing our dependence on conventional fuels.
Different
future technologies were studies and there benefits were presented along with
their working. Once these technologies become fully functional it will not only
make the travelling part of human comfortable but also reduce our dependence on
conventional fuels. It has been observed that these technologies are also environment
and user friendly.
Proceedings of the World Congress on
Engineering 2008 Vol II
WCE 2008,
July 2 - 4, 2008, London, U.K.
In
this research paper researcher highlights some of the biggest advances in the
field of automotive technology in the past 10 years have come in the area of
safety. Spurred by the improvements in the microprocessor speed,
miniaturization, and software development, the automobile continues to evolve.
In this new approach proposed, researcher going to have an electronic and a pneumatic
circuit to automatically control the traction of the vehicle. During ordinary
conditions, when the vehicle is driven down a straight road, or if the
difference between speeds of the two (rear) wheels is below a specified limit,
no signal will be generated by the electronic circuit. This helps the vehicle
negotiate the turns with better traction control as differential action is
unaltered. But if the difference between speeds is beyond a specified limit,
the signal will be generated by the electronic circuit which will actuate the
pneumatic circuit. This causes gradual braking on the faster wheel until it
gains traction. Hence, the wheels will never lose traction.
This system ensures a
reduction of more than 50% in the capital investment as compared to the already
existing systems can tilt the scales in the favour of the manufacturing company
and eventually the cost conscious consumer
The
system can be successfully incorporated in vehicles having pneumatic/hydraulic
braking system, with a view to provide improves traction. It can be put to use
in especially All Terrain Vehicles (ATV) and vehicles operating in high
altitude areas (vehicles for military application) where snow causes excessive
loss of traction. This system ensures a reduction of more than 50% in the
capital investment as compared to the already existing systems which ensures
the cost effectiveness of the endeavor.
11. Conclusion:
In modern world we are working on RAMS (Reliability,
Availability, Maintainability and safety). We are much interested in
determining the facts and figures. It becomes a part of past when nations are
dominant due to their oil reservoirs today developed world has started
gathering data and implement in their various industries such as automobile industry.
Future of automobile industry is also going to be bright due the field of IT.
We have developed many embedded systems like ECU discussed already. Putting all
this in a nut shell, we can conclude that the application of the knowledge of
engineering and statistics the automobile industry will be the brightest
industry in future due to its revolutions.
12.
References:
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12.
References:
1.
"Hybrid
Vehicle". 2018. En.Wikipedia.Org. https://en.wikipedia.org/wiki/Hybrid_vehicle.
2.
"What Is A
Hybrid Car And Should You Buy One?". 2018. What Car? https://www.whatcar.com/news/hybrid-car/.
3.
"Variable
Valve Timing". 2018. En.Wikipedia.Org. https://en.wikipedia.org/wiki/Variable_valve_timing.
4.
"Exhaust
Gas Recirculation". 2018. Dieselnet.Com. https://www.dieselnet.com/tech/engine_egr.php.
5.
"Continuously
Variable Transmission". 2018. En.Wikipedia.Org. https://en.wikipedia.org/wiki/Continuously_variable_transmission.
6.
2018. Jalopnik.Com. https://jalopnik.com/how-electronic-fuel-injection-works-499902815.
7.
Fast, Omer, and
Matthias Michalka. 2007. The Casting.
Köln: Verlag der Buchhandlung Walther König. http://www.ijmer.com/papers/Vol3_Issue2/AM32674677.pdf.
8.
Mechstuff4u.com.
(2018). Advantages and disadvantages
of carburetor. [online] Available at: https://www.mechstuff4u.com/2016/12/advantages-and-disadvantages-of_25.html
[Accessed 25 Apr. 2018].
9.
"Modern Fuel
Delivery Systems - Know Your Parts". 2018. Know Your Parts. https://www.knowyourparts.com/technical-resources/fuel-system/modern-fuel-delivery-systems/.
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