Labels

Saturday, 2 November 2013

Vehicle Dynamics III: Vertical oscillations

By Univ.-Prof. Dr.-Ing. Martin Meywerk - Professor for Automotive Engineering at the Helmut-Schmidt-University in Hamburg

From Bugatti Veyron to Volkswagen Beetle, from racing to passenger car: Learn how they behave on a country road and on the autobahn!

About this course
The mobility has influenced many areas of a human's life since the invention of the wheel. While, in the early days of motorized vehicles, technical developments concentrated on simple mechanical or electrical issues , in the past decades, the electronics and with it, the microprocessor technology have become a central part of innovation in vehicles. Future developments of trendsetting style will be the conversion of the drive train from purely internal combustion engine to hybrid or alternative powertrain systems, the car-to-car communication and the autonomous vehicles. Challenges that make these technical developments partly necessary, come from a desirable reduction in CO2 emissions and an increase in the active safety. To understand the recent developments, especially in the field of alternative propulsion strategies and also in the area of autonomous or semi-autonomous vehicles, a knowledge of the basic driving physics is essential, as these innovations can be understood solely as the underlying laws of physics are known.
For this reason three parts of the vehicle dynamics, the longitudinal, the lateral and the vertical dynamics are important.
Vertical oscillations
In this third part vertical dynamic aspects of vehicles will be illuminated, that means, we will describe a car running on a bumpy or rough street.
We will start with an survey of suspensions and springs and dampers. After this we will explain the description of rough streets and we will give an introduction to Fourier integrals. Then we will have a closer look at vertical models, and in the last fundamental part we will describe the conflict between driving Safety and comfort. The course will be finished by two applications from automotive mechatronics.
Course Structure
  1. Suspensions
  2. Springs, Dampers
  3. Stochastic Description of Road Surfaces
  4. Fourier Integrals
  5. Vertical Models
  6. Conflict Between Driving Safety and Comfort
  7. Application: Active Body Control
  8. Application: Active Stabilizing Rod
Learning Outcomes
  • You will know different kinds of suspensions, springs and dampers
  • You will know the description of rough and bumpy streets
  • You understand the Fourier integral
  • You understand the conflict between driving safety and comfort
  • You are able to calculate simple properties of a car
Workload
Per week: 135 - 260 min.
  • one video divided in 5 to 7 portions: 45 min.
  • 5 – 7 question-clusters for knowledge: 20 -30 min.
  • 2 – 3 question-clusters for comprehension: 25 – 50 min.
  • Guided calculation for application
  • P2P-problems to train analysis and synthesis skills: 45 min.
  • wrap-up: 0 – 90 min. (depends on your previous knowledge and your comprehension) Preparation of the exam: 30 h
Course Format
The course uses a mixture of Screencasts (with handwritten derivations, drawings, formulas), Powerpoint slides and videos from real cars, simulated cars and testrigs.
Assessments
To assess the different levels of learning this course will use different form of assessments:
  • Knowledge: Multiple choice,
  • Comprehension: correlation between statements and parts of diagrams, formulas or driving maneuver (visualized by short simulation videos);
  • Application: short guided calculations (open office),
  • Analysis: P2P-problems: longer calculations or drawings
Prior Knowledge
You should have been successful in university courses in basic mathematics and in basic engineering mechanics, especially you need:
  • Algebra
  • Trigonometric Functions
  • Differential calculus
  • Linear Algebra: Vectors, Coordinate systems etc.
  • Force, Torque, Equilibrium
  • Mass, Center of Gravity, Moment of Inertia
  • Method of Sections, Friction, Newton's Law
  • (Fourier’s integral)

Vehicle Dynamics II: Cornering

By Univ.-Prof. Dr.-Ing. Martin Meywerk ,Helmut-Schmidt-Universit├Ąt - Universit├Ąt der Bundeswehr Hamburg
https://iversity.org/c/31?r=6bd45

From Bugatti Veyron to Volkswagen Beetle, from racing to passenger car: Learn how they corner and drift, under- and over-steer!

About this course
The mobility has influenced many areas of a human's life since the invention of the wheel. While, in the early days of motorized vehicles, technical developments concentrated on simple mechanical or electrical issues , in the past decades, the electronics and with it, the microprocessor technology have become a central part of innovation in vehicles. Future developments of trendsetting style will be the conversion of the drive train from purely internal combustion engine to hybrid or alternative powertrain systems, the car-to-car communication and the autonomous vehicles. Challenges that make these technical developments partly necessary, come from a desirable reduction in CO2 emissions and an increase in the active safety. To understand the recent developments, especially in the field of alternative propulsion strategies and also in the area of autonomous or semi-autonomous vehicles, a knowledge of the basic driving physics is essential, as these innovations can be understood solely as the underlying laws of physics are known.
For this reason three parts of the vehicle dynamics, the longitudinal, the lateral and the vertical dynamics are important.
Cornering
In this second part lateral dynamic aspects of vehicles will be illuminated, that means the cornering of a car will be explained.
We will start with a simple single-track model, then we will describe the slip angle of a wheel. The slip angle results in cornering forces, which are essential for understanding lateral dynamics. After that, we will look at the dependency between longitudinal and lateral forces using Kamm’s circle and Krempel’s diagram. Then we will illuminate steady state cornering, stability and the influence of different weight distributions between inner and outer side wheels of the car. The course will be finished by two applications from automotive mechatronics.
Course Structure
  1. Single Track Model
  2. Slip Angle
  3. Cornering Force
  4. Kamm's Circle, Krempel's Diagram
  5. Steady State Cornering
  6. Stability
  7. Influence of Left/Right Weights
  8. Application: ESP, DSC
Learning Outcomes
  • You will understand basic principles of cornering of a car
  • You will know slip angle and cornering forces
  • You understand the single track model
  • You understand the steady state cornering, stability and the influence of different weight distribution between inner and outer side of the car
  • You are able to calculate simple properties of a car
Workload
Per week: 135 - 260 min.
  • one video divided in 5 to 7 portions: 45 min.
  • 5 – 7 question-clusters for knowledge: 20 -30 min.
  • 2 – 3 question-clusters for comprehension: 25 – 50 min.
  • Guided calculation for application
  • P2P-problems to train analysis and synthesis skills: 45 min.
  • wrap-up: 0 – 90 min. (depends on your previous knowledge and your comprehension) Preparation of the exam: 30 h
Course Format
The course uses a mixture of Screencasts (with handwritten derivations, drawings, formulas), Powerpoint slides and videos from real cars, simulated cars and testrigs.
Assessments
To assess the different levels of learning this course will use different form of assessments:
  • Knowledge: Multiple choice,
  • Comprehension: correlation between statements and parts of diagrams, formulas or driving maneuver (visualized by short simulation videos);
  • Application: short guided calculations (open office),
  • Analysis: P2P-problems: longer calculations or drawings
Prior Knowledge
You should have been successful in university courses in basic mathematics and in basic engineering mechanics, especially you need:
  • Algebra
  • Trigonometric Functions
  • Differential calculus
  • Linear Algebra: Vectors, Coordinate systems etc.
  • Force, Torque, Equilibrium
  • Mass, Center of Gravity, Moment of Inertia
  • Method of Sections, Friction, Newton's Law
  • (Lagrange’s Transf., Stability, ODE)

Vehicle Dynamics I: Accelerating and Braking

By Univ.-Prof. Dr.-Ing. Martin Meywerk - Professor for Automotive Engineering at the Helmut-Schmidt-University in Hamburg

https://iversity.org/c/30?r=6bd45

From Bugatti Veyron to Volkswagen Beetle, from racing to passenger car: Learn here how they speed-up and slow-down! 
About this course
The mobility has influenced many areas of a human's life since the invention of the wheel. While, in the early days of motorized vehicles, technical developments concentrated on simple mechanical or electrical issues , in the past decades, the electronics and with it, the microprocessor technology have become a central part of innovation in vehicles. Future developments of trendsetting style will be the conversion of the drive train from purely internal combustion engine to hybrid or alternative powertrain systems, the car-to-car communication and the autonomous vehicles. Challenges that make these technical developments partly necessary, come from a desirable reduction in CO2 emissions and an increase in the active safety. To understand the recent developments, especially in the field of alternative propulsion strategies and also in the area of autonomous or semi-autonomous vehicles, knowledge of the basic driving physics is essential, as these innovations can be understood solely as the underlying laws of physics are known.
For this reason three parts of the vehicle dynamics, the longitudinal, the lateral and the vertical dynamics are important.
Acceleration and Braking
In this first part longitudinal dynamic aspects of vehicles will be illuminated.
Clear and brief: acceleration and braking
In Detail: After an introduction we will look at driving resistances and slip, we will explain the demand of power and limits of a car, then we will clarify the needs for clutch and gear and we will look at the rear and front weights during acceleration and braking. The course will be finished by two applications from automotive mechatronics.
Course Structure
  1. Introduction
  2. Driving Resistance
  3. Slip
  4. Power Demand, Limits
  5. Clutch, Gearbox
  6. Front/Rear Weights
  7. Application: Anti-Lock Braking System
  8. Application: Recovery of energy
Learning Outcomes
  • You will understand basic principles of accelerating and braking a car
  • You will know the driving resistances and their influences to vehicle dynamics
  • You understand the discrepancy between demands and limits of powertrain
  • You understand the necessity of gears and clutch
  • You understand the correlation between braking, wheel load and recovery of energy
  • You are able to calculate simple properties of a car
Workload
Per week: 135 - 260 min.
  • one video divided in 5 to 7 portions: 45 min.
  • 5 – 7 question-clusters for knowledge: 20 -30 min.
  • 2 – 3 question-clusters for comprehension: 25 – 50 min.
  • Guided calculation for application
  • P2P-problems to train analysis and synthesis skills: 45 min.
  • wrap-up: 0 – 90 min. (depends on your previous knowledge and your comprehension) Preparation of the exam: 30 h
Course Format
The course uses a mixture of Screencasts (with handwritten derivations, drawings, formulas), Powerpoint slides and videos from real cars, simulated cars and testrigs.
Assessments
To assess the different levels of learning this course will use different form of assessments:
  • Knowledge: Multiple choice,
  • Comprehension: correlation between statements and parts of diagrams, formulas or driving maneuver (visualized by short simulation videos);
  • Application: short guided calculations (open office),
  • Analysis: P2P-problems: longer calculations or drawings
Prior Knowledge
You should have been successful in university courses in basic mathematics and in basic engineering mechanics, especially you need:
  • Algebra
  • Trigonometric Functions
  • Differential calculus
  • Linear Algebra: Vectors, Coordinate systems etc.
  • Force, Torque, Equilibrium
  • Mass, Center of Gravity, Moment of Inertia
  • Method of Sections, Friction, Newton's Law
  • (Lagrange's Equation)

Modelling and Simulation using MATLAB® - Free online courses by German University Professors

By Prof. Dr.-Ing. Georg Fries https://iversity.org/c/13?r=6bd45

Professor of Digital Signal Processing, Department of Engineering, RheinMain University of Applied Sciences, Wiesbaden

How can I build a robot, construct a space station on Mars or realize an adventurous new business venture? There can be no progress or innovation without modelling and simulation. Now you can learn how to design, prove and plan just about everything.
About this course
Technical progress wouldn’t be possible without modelling and simulation. They are starting point and basis in most cases of research and development. Modelling and simulation make a particular part or feature of the world easier to define, visualize, quantify and understand. Both require identifying and selecting relevant aspects of a situation in the real world and then using different types of models for different aims and defining the best fitting model parameters.
MATLAB is a high-level programming language and an environment for numerical computation and visualization. You can analyse data and create models for a wide range of applications, including signal processing and communications, image and video processing, control engineering and computational finance.
In this course you will learn the basics of modelling and simulation from an interdisciplinary perspective. In addition, we will teach you how to develop models using MALTAB and the block diagram environment Simulink.
Why this MOOC is interdisciplinary
Scientific disciplines have their own ideas about specific types of modelling. Such as conceptual models to better understand the subject, graphical models to visualize the subject, operational models to operationalize and mathematical models to quantify the subject. In this course, our experts from three disciplines look at modelling concepts from various angles:
  • Technological view
  • Economic perspective
  • Importance of knowledge management.
Course Contents
The course is divided in two sections. The first part (A) teaches the basics and is mandatory to all participants. Within the second part of the course (B) you have the opportunity to choose from a catalogue of applications (MOOClets) to work on selected examples.
Part A – Interdisciplinary Introduction to modelling and simulation
  • Modelling
  • Simulation
  • Introduction to MATLAB concepts
  • Building a business case
  • Methods to solve formal problems
  • Knowledge management
  • Introduction to Simulink
Part B – Selectable Applications of modelling and simulation (MOOClets)
You can choose three to five applications according to your preference and knowledge from the following catalogue:
  • Simulation of a water treatment plant
  • Application 'modelling a business base'
  • Application 'knowledge management'
  • Control engineering I – 'controlling Lego® NXT robots'
  • Control engineering II – 'line tracking with Lego® Segway'
  • Control engineering III – 'a Segway – how does it work?'
  • Image processing I – ‘statistics for image processing and machine learning’
  • Image processing II – 'a brief introduction to image processing'
  • Image processing III – ‘application of machine learning algorithms in a nutshell'
  • Quality measurement of video cameras (lenses and sensors)
  • Acoustic simulation of musical instruments
  • … (further chapters are planned)
Learning with the MOOC
During the term of the MOOC we will offer video lectures that convey modelling and simulation step by step in a descriptive way. You will exercise the issues in interactive tasks and weekly homework.
The MOOC platform is a networking tool. You can benefit from the peer-to-peer learning and the forum within the course. While not required, we recommend creating learning groups and to engage in the community.
Experimentation and playful learning are part of the MOOC.
Learning Outcomes
  • Students are acquainted with the concepts of modelling and simulation from an interdisciplinary point of view
  • Students are able to implement and simulate models using MATLAB/Simulink
  • Depending on the selected applications in part B of the course students get deeper know how in control engineering, image processing, machine learning, business case modelling, knowledge management and simulation of a water treatment plant.
  • Enthusiastic students with only simple programming knowledge get an understanding of the basic MATLAB programming.
Prior Knowledge
Mathematics and physics knowledge of secondary level education and programming knowledge are recommended.
Workload
  • Approx. 8-12 hours per week.
  • 12 Units including individual selected applications of Part B.
  • Experimentation and a deeper look at the topics as you like.

Friday, 16 August 2013

Low Pollution Alternate Fuel Vehicles

Isuzu is developing low-pollution vehicles using alternative energy sources or hybrid systems to reduce emissions. Such vehicles are not only a vital step toward achieving lower emissions of pollutants, they will also contribute to the more effective utilization of limited resources.

Compressed Natural Gas (CNG) Vehicles
The CNG-powered engines emit very low NOx carbon monoxide (CO) and hydrocarbons (HC) and virtually no particulate matter (PM) at all. Another characteristic of natural gas, of which the main constituent gas is methane, is that it produces very little CO2. Isuzu produces three-way catalytic converter-equipped CNG vehicles that achieve an excellent low-pollution emission performance.

CNG (Compressed Natural Gas) is available from the significant reserves of natural gas that exist in many places around the world. Unlike in the case of petroleum, the bulk of supplies are not concentrated in the Middle East and reserves of natural gas are considered to be much larger than those of petroleum. Accordingly, this fuel has an important role in maintaining a stable supply of energy.

ELF CNG-MPI (Multi Point Injection)
ELF CNG-MPI (Multi Point Injection)

[Advantages]Zero PM emission
Low NOx emission
Very low CO2 emission 


[Disadvantages]Short running distance
Heavy fuel container


Dimethyl Ethel Engine (DME) Vehicles

With various advantages, The DME engine is getting wide recognition as a next generation, alternative-fuel powerplant. DME emits no black smoke and very little PM and Nox.

Dimethyl Ether is made from charcoal and natural gas. It is very stable fuel which can be liquified under normal temperatures at low atmosperic pressure. Easy transportation and storage is also its advantage.
DME engine

[Advantages]
Zero PM emission and black smoke
Very low Nox emission
Good fuel economy equivalent to diesel engine
Easy handling

[Disadvantages]
Shorter running distance than diesel engine
Unsufficient Infrastracture


Diesel Hybrid Vehicles

Hybrid vehicles are designed to realize low pollution and energy saving by dual power sources. Isuzu's Elf diesel hybrid achieves low-CO2 emission levels and high fuel efficiency by fully extracting energy available when the vehicle decelerates. It uses diesel for fuel, needs no special infrastructure, and can be serviced anywhere. In addition, the Elf Diesel hybrid truck employs Isuzu's original hybrid system, which was optimized for light-duty trucks. The system achieves excellent fuel economy compared to other hybrid vehicles, and delivers the high durability and safety performance required by commercial vehicles at the same time.
The Elf diesel hybrid truck has the following features:
• The hybrid system is based on the 4HL1 diesel engine. In addition to assisting the engine by adding an electric motor, the Smoother-E automatic shift system allows high-efficiency regenerative energy and automatic shifting in fuel-saving speed ranges.
• For the first time on a domestic truck, a Lithium-ion battery is used that provides approximately 3 times longer life than a nickel metal hydride battery.
• A PTO-type parallel drive hybrid system is employed, so that even if a failure occurs in the hybrid system, the motor and generator being installed on a shaft different from that of the engine, driving can be continued on just the diesel engine, without interference to the engine driveline.
ELF Diesel Hybrid
ELF Diesel Hybrid

[Advantages]
Improved fuel consumption resulting in lower CO2 emissions
Reduced exhaust emissions during start up and acceleration

[Disadvantages]
Complex systems and high maintenance costs


When starting and accelerating, or when the engine is under a heavy load, the vehicle runs on both the engine and electric motor using battery power


 

Vehicle runs as a fuel-efficient diesel engine during constant-speed runs only. The Smoother-E automatic shift changes speeds automatically for optimum fuel economy.

 

When decelerating, Smoother-E automatic shift automatically disengages clutch to prevent loss of regenerative energy, charging on battery efficiently.

 

After stopping, moving the shift lever into the N position will stop the engine automatically. Moving the lever to D restarts the engine. Gas emission is reduced, while fuel economy is improved at the same time.


Fuel Cell Vehicles

Fuel cell vehicles are highly advanced low-pollution vehicles that generate electricity through a chemical reaction between hydrogen and oxygen and use this electricity to drive a motor. R&D is currently proceeding into a system for storing hydrogen in a special alloy and a system utilizing methanol. Fuel cells are highly fuel-efficient, so they are considered as the next-generation of vehicle powerplants.illust image
When water is electrolyzed it is split into hydrogen and oxygen. The principle of the fuel cell is based on the reversal of this reaction.

CO2 Reduction Technologies

Diesel Engine Combustion Systems
The quality of combustion in diesel engines depends on how quickly and how completely the fuel mixes with the air as it is injected into the combustion chamber. Two basic systems have been devised to improve this mixing: direct-injection and indirect-injection.


Direct-Injection
Direct-Injection System
The direct-injection system introduces the fuel directly into the combustion chamber. Direct-injection promotes good fuel economy, but the air swirling is not strong enough to achieve an ideal mixture with the fuel. This weakness is overcome with specially designed chambers and air-intake ports, and by the use of high-pressure fuel injection. Direct-injection diesel engines are gathering increasing popularity. They are now used in nearly all trucks with payloads of four tons or more and also in a significant proportion of passenger cars in Europe. The most popular form of direct-injection system provides a strong swirl of air in the combustion chamber to aid the air-fuel mixing process, with the fuel being injected under high pressure from four or five nozzle holes.

 Advantages
Minimized surface area raises thermal efficiency and reduces heat loss, resulting in good fuel economy.
Simple cylinder head design is durable and reliable, partly because it is largely unaffected by heat or pressure distortion.
Engine starts easily, and preheating with a glow plug is not necessary.
 Disadvantages
Current designs produce more NOx emissions than indirect-injection systems.
Not ideally suited to high-revolution vehicles (passenger cars) due to difficulties in creating an ideal swirl.

Indirect-Injection
Indirect-Injection System
The indirect-injection system is currently limited to use in passenger cars and light-duty trucks. The most popular design features a spherical swirl chamber in the cylinder head. Air is forced into the chamber by the piston and begins swirling rapidly, which promotes a good mix when the fuel is injected. A preliminary combustion of the mixture takes place and heat rises, forcing the remaining unburned fuel into the chamber at high velocity, where it mixes well with the air and undergoes complete combustion.

 Advantages
Suitable for fast engine speeds with high rpm.
Less vibration and noise.
 Disadvantages
Additional chamber adds to design cost.
Greater surface area leads to heat loss and reduced fuel economy.
Higher temperature operation wears out parts faster.

Intercooler-Equipped Turbocharger

Turbocharger
Intercooler-Equipped Turbocharger
A turbocharger is a mechanism that increases the amount of air supplied to an internal combustion engine at higher than normal pressure by means of a turbine powered by the exhaust gases. By allowing more air to enter the cylinder while maintaining the exhaust amount at the same level, a turbocharger can improve combustion efficiency and improve the power output.


Intercooler

An intercooler is a device that cools the supplied air, which is heated to a high temperature upon being compressed in the turbocharger. Then, it will send the cool high-density air to the cylinder.


Advantages of Turbo-Charged Engines
The 6WF1-TC direct-injection engine
The turbocharger can supply large displacement to the cylinder, so that a high level of output can be obtained with a small exhaust volume. Achieving high power with a small exhaust volume means that the engine's weight and size can be made smaller, and this translates into a lighter vehicle weight and improved fuel efficiency. Moreover, a turbo-charged engine can generate 20% to 50% more torque* compared to a non-turbo-charged engine with the same displacement. These advantages make turbo-charged engines ideal for vehicles used for long-distance, high-speed transportation. On the other hand, non-turbo-charged engines feature high levels of torque in the low speed range, which gives them a better startup and acceleration performance and makes them suitable for vehicles used mainly for city driving involving repeated starting and stopping. In recent years, turbo-charged engines are getting more popular for their high fuel economy and remarkable power performance.

* Torque
Torque is the rotational force generated by the movement of the crankshaft. The unit of torque is the Newton meter (Nm) or the kilogram meter (kgm). In principle, the higher an engine's combustion power, the greater the amount of torque it generates. For example, if a one-meter-long arm is fixed at right angles to a shaft and a 1kg weight is set at the tip, the force exerted on the shaft is 1Nm (1kgm).

Diesel Engines and Gasoline Engines

Diesel engines possess a diversity of features that other internal combustion engines can't match. The advantages of diesel include good thermal efficiency that translates into relatively low CO2 emissions, as well as powerful torque even at low speeds and high durability.
In his 1892 thesis concerning the "Theory and structure of a rational thermal engine that should replace the steam engines and internal combustion engines known today", Rudolf Diesel, the diesel engine's inventor in Germany, described the new engine's basic principles. These are: (1) at first only air is fed into the combustion chamber, then the fuel is sprayed in after the air is compressed; and (2) the air compression ratio is set high so that the air temperature becomes much higher than the combustion point of the fuel.
Diesel engines operate on a self combustion or compression combustion system that does not require ignition plugs and a non-uniform mixing method in which the air and fuel are sent separately into the combustion chamber where they mix together and spontaneous combustion takes place.


Exhaust emission levels are very different between diesel engines and gasoline engines. Diesel engines emit higher levels of nitrogen oxides (NOx) and particulate matter (PM) than gasoline engines.

ItemDieselGasoline
Exhaust emissionsNOx-Better
PM-Better
CO2 (fuel consumption related)Better-
OthersNoise level-Better
Engine torqueBetter-
DurabilityBetter-

Characteristics of Diesel Emissions
Among the substances contained in exhaust emissions, those that have particularly impacts on the environment are carbon dioxide (CO2), carbon monoxide (CO), hydrocarbons (HC), nitrogen oxides (NOx) and particulate matter (PM). Especially CO2, PM and NOx are attracting serious attention, and a variety of technologies have been developed in order to reduce their generation.

CO2 (Carbon Dioxide)

What is CO2?
CO2 or carbonic acid gas is colorless odorless gas present naturally in the air. The concentration of CO2 is increasing due to the combustion of fossil fuels and the cutting of tropical rainforests. It is important to conserve fossil fuels as much as possible in order to reduce the amount of CO2 generated. Vehicles with good fuel consumption emit lower CO2What happens when the atmospheric CO2 level rises?
Its connection with global warming is most worried. As the average temperature rises, sea levels rise and abnormal climates occur more frequently. The effects of these changes on people around the world are very serious.

PM (Particulate Matter)

What is PM?
PM is a general term for the various kinds of particulate matter emitted by diesel and other engines. This matter consists mainly of soot, half-combusted fuel particles, a lubricated oil component called SOF (Soluble Organic Fraction), and sulfates generated from the sulfur contained in the light oil fuel. PM also includes SPM*, which consist of particularly small particles.
What happens when PM emissions increase?
PM is one of the airborne pollutants that has a direct effect on human health. Breathing in large amounts of PM can result in respiratory problems or chronic lung disease.
* SPM (Suspended Particulate Matter): Among the PM present in engine exhaust gas, those with diameters of less than 10 microns are categorized as SPM. Environmental standards stipulate maximum SPM emission levels.


NOx (Nitrogen Oxides)

What is NOx?
NOx is a general term for a variety of chemical compounds formed in reactions between nitrogen and oxygen at high temperatures. The amount of NOx generated increases as combustion becomes more complete, so to reduce NOx generation the temperature of the reaction must be lowered. This fact makes it difficult to reduce NOx and PM generation simultaneously.
What happens when NOx emissions increase?
NOx is a major cause of photochemical smog and acid rain. It has a huge influence on natural eco-systems by damaging forests and acidifying lakes and marshes. In large cities, high local NOx concentrations may have negative effects on the human respiratory system.
Features of Diesel Engines
Fuel: Diesel light oil
Fuel supply system: High-pressure direct injection into cylinder via fuel pump
Air-fuel mixing: Non-uniform mixing
Ignition system: Compression-induced spontaneous combustion
Compression ratio: 15.5-23
Output control system: Controlled exclusively by fuel injection amount (fixed intake air amount, mixing ratio control)

Combustion
Diesel Engines

In diesel engines, air is drawn into the cylinder and highly compressed, after which fuel is sprayed into the cylinder under high pressure. Ignition occurs spontaneously as a result of the high temperature generated through compression.
Thermal Efficiency
Ratio of heat converted into power against total heat generated during combustion
Diesel Engines Feature High Thermal Efficiency
Thermal Efficiency Ratio=Ratio of heat converted into motive power: 35-42%

CO2Diesel engines' high thermal efficiency translates into low fuel consumption.
20-40% lower than gasoline engines
Durability
Working life of 300,000 - 1,000,000 km or more
(from car-mounted engine data)
PerformanceDiesel engines generate flat torque from the low speed range, so diesel vehicles are easy to drive.
Based on in-house data


Features of Gasoline Engines
Fuel: Gasoline
Fuel supply system: Carburetor or low-pressure intake-pipe fuel injection system
Air-fuel mixing: Pre-injection uniform mixing
Ignition system: Spark ignition
Compression ratio: 8-10.5
Output control system: Suction mixture air amount control via throttle valve (fixed mixing ratio)

Combustion

In gasoline engines, air and fuel are mixed in advance and then drawn into the cylinder and compressed. The compressed mixture is ignited by an ignition plug.
Thermal Efficiency
Ratio of heat converted into power against total heat generated during combustion
Thermal Efficiency Ratio=Ratio of heat converted into motive power: 25-30%

CO2Since gasoline engines have a lower thermal efficiency than diesel engines, their CO2 exhaust amount is correspondingly greater.
DurabilityWorking life of 100,000 - 300,000 km or more
(from car-mounted engine data)
PerformanceGasoline engines generate torque during high-speed rotation.
Source: ISUZU