1. INTRODUCTION
To increase the thermal efficiency
for internal combustion engines of automobiles is always the field of
innovation for researchers. R & D Department of big car manufacturing
giants always looking after this to increase the fuel economy and get better
mileage with proper power. No matter however we are ahead in the innovations,
but still modern gasoline engines have maximum thermal efficiency around 25-30
% to get useful power and rest 70-75% is rejected as a heat without being
turned in useful power.
Firstly, there are numerous factors
affecting the fuel economy of automobiles but I am going to narrate one of
them, incomplete combustion of fuel. Incomplete combustion of fuel is the
reason behind the poor fuel economy as well as the CO and NOx emissions.
To overcome this situation, fuel
magnetizers can be used.
2. HOW TO INCREASE ECONOMY OF FUEL??
There are various ways to increase the economy of fuel. Some of them are
listed below:
·
By reducing the overall weigh of a vehicle.
·
By proper lubrication of various parts.
·
By applying proper lubricating oil.
·
By reducing rolling resistance.
·
By improving fuel characteristics or by adding proper fuel additives in
fuel.
·
By improving engine characteristics (Eg : Compression Ratio, Piston and
Cylinder, Transmission, Setting up proper crank angle and firing order).
·
By proper designing of vehicle body for aerodynamic shape.
·
By reducing the total load on vehicle.
·
By proper and scheduled maintenance.
·
By accelerating and decelerating the vehicle in standard manner.
2.1 By using Fuel Magnetizer
2.1.1 Introduction
To increase the thermal efficiency
for internal combustion engines of automobiles is always the field of
innovation for researchers. R & D Department of big car manufacturing
giants always looking after this to increase the fuel economy and get better
mileage with proper power. No matter however we are ahead in the innovations,
but still modern gasoline engines have maximum thermal efficiency around 25-30
% to get useful power and rest 70-75% is rejected as a heat without being
turned in useful power.
Firstly, there are numerous factors
affecting the fuel economy of automobiles but I am going to narrate one of
them, incomplete combustion of fuel. Incomplete combustion of fuel is the
reason behind the poor fuel economy as well as the CO and NOx emissions.
To overcome this situation, fuel
magnetizers can be used.
2.1.2 Structure of Fuel Magnetizer
In the structure of fuel magnetizer, it consists of pair of magnet; each covered by non-magnetic material, and can be fitted over fuel pipe and clamped as fuel line is covered under magnetic field of high power magnets. The magnets are placed in such a way that they attract each other means one would be North Pole and other would be South Pole. If the engine has carburetor, the magnetizer should be clamped ahead of it on fuel line.
 | ||||
Fig.1 US
Patent # 5,664,546 - A front elevation of Magnetizer
[(1) two longitudinal half body casing (2) made of non-magnetic material joined to each other by a clamp (3) that keeps them attached to a pipe (4) through which runs the fuel.]
2.1.3 Operating Principle
Magnetic
field can affect the fluids that exhibits paramagnetic (at least one unpaired electron) and diamagnetic (paired electrons) behavior, even that is not
electrical conductive.
2.1.4 Working
When the fuel passes through the magnetizer zone in fuel
pipe, strong magnetic field de-clusters the hydrocarbon association so it
becomes normalized, independent and equally distanced with each other, like
burning of coal brick (clustered) or its dust (de-clustered).
As the gasoline is hydrocarbon (C8H18),
Magnetic field converts the hydrogen from its Para state to ortho state which
is more volatile and creates Cationic State, so it rapidly creates bond with
oxygen, which leads to fuel efficient combustion process.
Fig.4
Magnetizer Technology in action
[Courtesy: http://mundi.com/pools.htm]
Moreover, a test conducted under
Federal EPA Code 40 CFR, Sec.51.351 by Magnetizer Products Company(www.magnetizerproducts.com) shows the
results of amount of HC and CO % decrease for some automobiles and increase in
mileage which shows that magnetizer had increased efficiency about 10-20%, even
when it is used with Catalytic Converter it can reduces about 50% of NOx&
CO emissions.
2.2 By controlling Rolling Resistance2.2.1 Introduction
History of tire development is
mainly roam around innovations and improvements in tire designs, materials used
and manufacturing techniques. 3 major period of tire development a) are the
early era of automobile from 1900-1930 b) middle era when synthetic rubber
became common around 20th century c) the mass introduction of radial
tires in north America in beginning of
1970.
Drivers are supposed to pay
attention on how their car tires effect on fuel efficiency. Actually, tires plays crucial role in a car’s
fuel economy. According to a research, tires are responsible for about 15-25%
of typical fuel consumption. Tires are also related with aerodynamic and
inertia losses, which results in a total amount of fuel consumption due to
tires.
According to a survey, each year
Americans spend about $ 20 billion for the replacement of tires. Wear and tear
is the most affecting factor for replacement of tires. Friction takes place
between tire and road, (mainly result of tread compound and its design), tire
air resistance, energy losses from the tire deformation under numerous loads
and internal stresses, which all affect the fuel economy.
Designing of tire contribute to
vehicle’s fuel economy in different ways like aerodynamic drag force, inertia
losses and rolling resistance. Among these, rolling resistance is most
significant factor to improve fuel efficiency.
2.2.2 Influence of tires on fule consumption
In every significant respect, the
performance and quality are far better than predecessor tires. Tires wear
longer are more resistant to damage, handle and track better, and are easier to
maintain.
With every innovation in tire,
engineers have to balance with cost, government regulations, consumer demands
and operational demands. The amount of fuel consumed by a motor vehicle is
mainly affected by converting the chemical energy into the useful power.
As tire rolls under the weight of
vehicle, it causes changes in shape and deformation. In this process mechanical
energy which is available to turn the wheel is converted into heat and
dissipated from the tire. So, it requires more fuel to replace this lost
energy.
2.2.3 Rolling Resistance
It is the force that resist the motion when a body rolls on
surface is called rolling resistance. Rolling drag is energy consumed per unit
distance by tire. Rolling friction is one of the force which acts in opposite
direction of driver.
Fig.5 Significance of Rolling Resistance
[Courtesy: www.engineeringtoolbox.com]
Rolling resistance could be expressed as,
Fr= C*W
C
= Rolling Resistance co-efficient & W = mg
How rolling resistance affecting
the fuel economy?
The main reason for rolling drag is
when tire is in motion and contacted with road surface it changes shape and
cause deformation of tire. It causes energy loss due to heat and its known as
Hysteresis. More fuel is required to push the vehicle on road.
According to the survey, tires
contribute around 20-30 percent of the total fuel consumption by a vehicle,
which is greatly impacted by the rolling resistance of tires.
Fig.6 Example energy flows for a late-model midsize passenger car
(a) Urban driving (b) Highway driving
[Source:
U.S. Department of Energy]
2.2.4 Factor Affecting Rolling Resistance
Composition of tires plays crucial
role in determining the loose due to rolling resistance. Selection of tires
based on design requirements are done for wear and tread pattern.
Rolling resistance is basically
caused by heat dissipation in rubber. The factors that cause total rolling
friction are:
1). Aerodynamic drag of the
rotating tire
2). Hysteresis loss
3). shearing, compression, micro
slippage of tire and ground
Some factors also affect rolling
friction:
Mass of tire–Heavy tire creates
more downward force on the road. Tire compression and rolling resistance both increases
due to mass.
Cornering- During turn vehicle goes
slow down. It results in strong downward force on the ground, which increases
resistance. The rubber of tire twists on the road and causes heat due to
friction.
Effects by tread compound- Most of
rolling friction about 35-50 percent, comes from treads of tire. So its become
very important for manufacturers to design fuel efficient compounds of traed.
More the material in the tire in tread area, the more the rolling resistance.
It means that new tires have more rolling resistance, means when you buy new
tire expect some fuel loss. Winter tires, snow tires, mud tires and off road
tires have more rolling resistance than all-season tires.
|
Fig.7 Contribution of Tire Components on Rolling Resistance
2.2.5 Wheel Alignment
Fig.8 Effect of Wheel Alignment on Rolling Resistance
2.2.6 Inflation Pressure
Inflation pressure plays an
important role to reduce rolling resistance. Under inflated tires have less
life if the tire pressure is not proper. Pressure at the centre of tire is not
sufficient to bear the load. These tires distorts and bend more, which causes
overheating and finally increases rolling friction. In case of over inflated tire,
more pressure in tire decreases grip of treads with road. Rolling friction is
affected by the tire inflation. High pressure tire rolls easily. Inflation
pressure has a strong effect on cornering force.
Fig.8 Inflation Pressure
Fig.9 Inflation in tires
2.2.7 Tire types and patterns
Fig.10 Cross-section of tire
(a)
Rib pattern (b)
Block pattern
Fig.11 Types
of tire patterns
2.2.8 Rubber Compound
Rubber compounds – Rubber
compounds can also contribute to reduce heat loss and lowering rolling
resistance. According to Mr. P K Mohamed, Chief
Advisor, R&D, Apollo explains: “New materials, technologies and better processes are helping tire
engineers now to overcome the problem of compromises. Identification of silica
as a filler made possible by better processing capabilities enabled to achieve
reduction in rolling resistance without compromising wet grip.” Combinations of
different rubbers that are synthetic and natural are in trend in new
technologies. Low rolling resistance can be achieved by using Solution stirene
butadiene rubber (SSBR).
To reduce rolling resistance we
have to concentrate on less deformation of tires which will reduce heat loss. Tire
deforms as its roll. The sidewalls flex over and over and tread goes circular
to flat. All this deformations are the major contributors for heat loss and
finally causes rolling resistance.
2.3 Increase the fuel economy by Aerodynamic shape of a vehicle
2.3.1 Introduction
When a vehicle moves along a road, it experiences a
resistance force of air which is in the opposite direction of the movement of a
vehicle. Resistance of air plays a significant role while designing a vehicle.
As much as the air resistance increases, a vehicle have to make more effort to
compensate the resistance offered by air and so the greater amount of fuel is
burnt. So it is very essential to design a vehicle in such a way that the
resistance offered by air to the vehicle is minimum so that the air can pass
smoothly along the body of a vehicle. A considerable amount of fuel can be
saved by proper designing of shape of a vehicle. As the speed of a vehicle
increases the amount of air resistance to a vehicle increases. So it is very
necessary to take in account the resistance of air for the vehicles which are
going to be operated at higher speeds generally above 50 mph.
2.3.1 Aerodynamic Drag
Aerodynamic Drag is the imbalance of pressure or resultant
forces acting on the vehicle when the vehicle is passed through air. Generally
the magnitude of forces acting on the vehicle depends upon following factors.
a)
Speed of a
vehicle
b)
Frontal area
of a vehicle
c)
External
shape of a vehicle
Aerodynamic drag is one of the
most significant term contributing in requirement of power for a vehicle
generally at a higher range of speeds.
Fig.11 Principle of
Aerodynamics
Fig.12 %MPG gain for different
travelling zone
As the above
graph shows, economy of fuel on an interstate duty cycle has major aerodynamic
air and on an intercity cycle the impact is very little.
Following graph shows the contribution in consumption of
power for aerodynamic drag and Rolling Resistance. In the following graph
Y-Axis shows the value of horsepower and X-Axis shows the speed of a vehicle in
MPG.
Fig-13 Contribution of Aerodynamic Drag
and Rolling Resistance in
Power consumption of a vehicle
2.3.3 Drag Coefficient(CD)
In a broad meaning, term Drag Coefficient is the
dimensionless quantity that is used to quantify the drag of resistance of an
object in the fluid environment such as air and water. In aerodynamics, the
fluid medium is air so the Drag Coefficient is the resistance of an object in
air. Drag Coefficient is generally denoted by CD.
Fig .15 Significance of Drag
Coefficient
When a
vehicle moves at certain speed, the pressure in front of a vehicle is always
greater than the pressure at the rear side of a vehicle due to shape of vehicle
and flow of air. So the resultant pressure force always tries to oppose the
speed of a vehicle.
2.3.4 Relationship between Aerodynamic Drag Force and consumption of fuel
From the relationship of Aerodynamic Drag force and fuel
consumption, it is seen that we should choose the proper engine cycle having
fair efficiency. We should choose the frontal area as well as the other body of
a vehicle in and a way that it minimizes the air resistance. The cross
sectional area of an automotive should be as small as possible to minimize the
drag force offered by air. A vehicle should be driven at comparatively lower
speed on highways to minimize the unbalanced force on a vehicle so that the
fuel require to compensate the unbalanced forces are minimum. The relationship
between Aerodynamic Drag and Consumption of fuel is shown in the figure below.
Fig.16 Relationship between changes
in drag and fuel consumption
2.3.5 Aerodynamic Treatment of automotive
In
guidelines of Cummins, The comparison of vehicles having aerodynamic treatment
and vehicles having no aerodynamic treatment are described with the help of
graph.
2.3.5.1 No Aerodynamic Treatment
In this
case, 264 horsepower is needed to overcome all of the forces acting on the
truck and to keep it rolling at 65 mph. Aerodynamic forces (wind resistance)
account for 145 hp (over half) of the power demand. As shown in the graph
below, the resistance of tires makes the biggest impact when the speed of a
vehicle is lower than 50 MPG while the Aerodynamic Drag force have a greater
impact on the fuel consumption and power requirement when the vehicle is driven
over 50 MPG.
Fig.17 Power Requirement with no
aerodynamic aid
2.3.5.2 Full Aerodynamic Treatment
Aerodynamic treatments can reduce the horsepower required to
move the truck by 30 to 35 horsepower. Notice in this example that a vehicle
equipped to reduce air resistance also reduces power output from 145 hp to 113
hp, a reduction of 22%.
Notice that these aerodynamic treatments are more effective
at higher speeds as represented by the increased vertical depth of the red
graph below.
Also notice that the power required to overcome things like
tire rolling resistance are not affected by the aerodynamic aids.
Fig.18 Power Requirement with full
aerodynamic aid
2.3.5.3 Comparison of fuel consumption with full Aerodynamic treatment and with No Aerodynamic treatment of automotive
The following graph shows how the impact of aerodynamic
treatments depends on speed. For trucks in pickup and delivery operations in
urban areas, the cost and maintenance of aerodynamic treatments may outweigh
the benefits. However, for an over-the-road (OTR) tractor and trailer, the fuel
savings from aerodynamic treatments may quickly offset the higher initial
purchase price of the equipment.
At approximately 0.3 lb./BhpHr fuel consumption, a reduction
of 35 Bhp required to cruise at 65 mph results in a savings of about 10.5 lbs.
of fuel every hour (0.3 x 35 = 10.5). Since diesel fuel weighs about 7.1
lb./gal., this amounts to a savings of 1.5 gallons of fuel saved every hour
(10.5/7.1 = 1.5). For a truck running 10 hours per day, that’s 15 gallons of
fuel saved per day. At $2.45 per gallon of fuel, the dollar savings is $36.75
per truck per day.
Fig. 19 Aerodynamic Power Requirement Comparisons
2.3.6 Improved Fuel Economy with closed spacing
At
large spacing, close-following results in drag saving (fuel saving) for the
trail vehicle because the trail vehicle experiences a diminished dynamic
pressure in the wake. The two vehicles collectively have less drag than the two
in isolation. This can be regarded as a decrease in drag coefficient.
At sufficiently
close spacing—less than one vehicle length in the case of a car, or one vehicle
height in the case of a truck—the interaction is stronger. At
sufficiently close spacing—less than one vehicle length in the case of a car,
or one vehicle height in the case of a truck—the interaction is stronger.
Fig.20 Large space
trail vehicle
Fig.21 Closed space trail vehicle
Fig.22 Wind tunnel test for vehicle
spacing
Fig.23 Test Result for saving in
Average fuel consumption
Average fuel consumption
saving for three-vehicles at 0.8 car length spacing is ≈ 6-7%.
2.3.7 List of items that can improve the fuel ecomomy of automotive
·
Full Roof
Deflector
·
Fairings
·
Sloped Hood
·
Round
Corners
·
Aero Bumpers
·
Air Dam
·
Spoilers
·
Aero
Headlights
·
Slanted
Windshields
·
Curved
Windshields
·
Aero Mirrors
·
Side
Extenders
·
Side Skirts
·
Under Hood
Air Cleaner
·
Concealed
Exhaust System
·
Recessed
Door Hinges
3.0 References
c) Research paper on “Fuel Energizer” , IJIRD IISN :
2278-0211 VOL. 2 ISSUE-4
d) Transportation Research Board Special Report 286 by
National Research Council of the national academies.
e) www.Darttruckingjoles.com
i) Secrets of Fuel Economy ( Physics of MPG) by Cummins
j) Reducing Aerodynamic Drag and Fuel Consumption by Fred
Browand, University of Southern California
h) Aerodynamic Design optimization of Rear Body
Shapes of a sedan for drag reduction. 
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