The document discusses the design requirements of combustion chambers in spark ignition engines. It states that good combustion chambers aim to provide high power output, efficiency, smooth operation and low emissions. Key design considerations include high compression ratios, turbulence, compact size, and valve and spark plug placement. Historically, T-head, L-head, and I-head (overhead valve) designs have been used, with overhead valve becoming prevalent for its performance at high compression ratios. Modern combustion chamber designs include bath tub and wedge types within cylinder heads.
The document discusses different types of combustion chambers used in spark ignition engines. It describes the T-head, L-head, I-head (overhead valve), and F-head combustion chamber designs. The T-head was the earliest type but was prone to knocking. The L-head and F-head were improvements that used a single camshaft but still had valves in the block. The overhead valve design with both valves in the cylinder head became most common after 1950 as it allows for higher compression ratios and improved performance. The document lists advantages of the overhead valve design such as reduced pumping losses and knock susceptibility.
The document discusses Homogeneous Charge Compression Ignition (HCCI) engines. HCCI engines compress the fuel-air mixture to the point of auto-ignition, requiring no spark plug. This allows for lower emissions and improved fuel efficiency compared to traditional engines. However, auto-ignition is difficult to control precisely. Various methods are used to control the combustion timing, such as variable compression ratios or induction temperatures. HCCI engines also have a smaller adjustable power range than traditional engines. Major automakers are researching HCCI as a promising future technology.
The document discusses the key stages of combustion in a compression ignition (CI) engine:
1. Ignition delay period where fuel does not ignite immediately upon injection.
2. Uncontrolled combustion period of rapid, steep pressure rise as accumulated fuel burns.
3. Controlled combustion period where further pressure rise is controlled by injection rate.
4. Afterburning period where unburnt fuel particles continue burning with oxygen.
It also examines factors affecting the ignition delay period like compression ratio, injection timing, and fuel quality. Knocking in a CI engine can occur if the ignition delay is too long, causing excess fuel accumulation and an abrupt pressure spike.
The document discusses combustion in spark-ignition (SI) engines. It defines combustion as a chemical reaction in which fuel combines with oxygen, liberating heat energy. In an SI engine, fuel and air are mixed and inducted into the cylinder where combustion is initiated by a spark at the spark plug near the end of the compression stroke. There are three stages of combustion: ignition lag, flame propagation, and after burning. Abnormal combustion phenomena like pre-ignition and knocking can occur if conditions are not suitable. Factors like turbulence, fuel-air ratio, temperature and pressure, compression ratio, and engine variables affect the flame speed and combustion process.
This document discusses emissions and emission control strategies in internal combustion engines. It covers the formation of various emissions like carbon monoxide (CO), nitrogen oxides (NOx), hydrocarbons, and particulates in both spark ignition (SI) and compression ignition (CI) engines. It also discusses emission control methods like catalytic converters and exhaust gas recirculation (EGR). The key points are: emissions form due to incomplete combustion and high temperatures; a three-way catalytic converter controls CO, HC, and NOx using platinum, palladium and rhodium; and EGR reduces NOx by lowering combustion temperatures but increases particulates.
This document summarizes different types of combustion chambers used in compression ignition (CI) engines. It describes direct injection combustion chambers like shallow depth, hemispherical, cylindrical, and toroidal chambers. It also describes indirect injection combustion chambers like swirl, pre-ignition, and air-cell chambers. Each type of chamber is briefly explained along with advantages it provides in fuel combustion. Direct injection chambers inject fuel directly into the cylinder while indirect injection chambers use a pre-chamber to improve combustion.
This document discusses spark ignition engines. It covers mixture requirements, fuel injection systems, stages of combustion including normal and abnormal combustion like knocking. Knocking occurs when pockets of air-fuel mixture explode outside of the normal combustion front. Factors that affect knocking include density factors, time factors, and composition factors. The document also discusses combustion chambers and their role in smooth engine operation and high power output.
The document discusses different types of combustion chambers used in spark ignition engines. It describes the T-head, L-head, I-head (overhead valve), and F-head combustion chamber designs. The T-head was the earliest type but was prone to knocking. The L-head and F-head were improvements that used a single camshaft but still had valves in the block. The overhead valve design with both valves in the cylinder head became most common after 1950 as it allows for higher compression ratios and improved performance. The document lists advantages of the overhead valve design such as reduced pumping losses and knock susceptibility.
The document discusses Homogeneous Charge Compression Ignition (HCCI) engines. HCCI engines compress the fuel-air mixture to the point of auto-ignition, requiring no spark plug. This allows for lower emissions and improved fuel efficiency compared to traditional engines. However, auto-ignition is difficult to control precisely. Various methods are used to control the combustion timing, such as variable compression ratios or induction temperatures. HCCI engines also have a smaller adjustable power range than traditional engines. Major automakers are researching HCCI as a promising future technology.
The document discusses the key stages of combustion in a compression ignition (CI) engine:
1. Ignition delay period where fuel does not ignite immediately upon injection.
2. Uncontrolled combustion period of rapid, steep pressure rise as accumulated fuel burns.
3. Controlled combustion period where further pressure rise is controlled by injection rate.
4. Afterburning period where unburnt fuel particles continue burning with oxygen.
It also examines factors affecting the ignition delay period like compression ratio, injection timing, and fuel quality. Knocking in a CI engine can occur if the ignition delay is too long, causing excess fuel accumulation and an abrupt pressure spike.
The document discusses combustion in spark-ignition (SI) engines. It defines combustion as a chemical reaction in which fuel combines with oxygen, liberating heat energy. In an SI engine, fuel and air are mixed and inducted into the cylinder where combustion is initiated by a spark at the spark plug near the end of the compression stroke. There are three stages of combustion: ignition lag, flame propagation, and after burning. Abnormal combustion phenomena like pre-ignition and knocking can occur if conditions are not suitable. Factors like turbulence, fuel-air ratio, temperature and pressure, compression ratio, and engine variables affect the flame speed and combustion process.
This document discusses emissions and emission control strategies in internal combustion engines. It covers the formation of various emissions like carbon monoxide (CO), nitrogen oxides (NOx), hydrocarbons, and particulates in both spark ignition (SI) and compression ignition (CI) engines. It also discusses emission control methods like catalytic converters and exhaust gas recirculation (EGR). The key points are: emissions form due to incomplete combustion and high temperatures; a three-way catalytic converter controls CO, HC, and NOx using platinum, palladium and rhodium; and EGR reduces NOx by lowering combustion temperatures but increases particulates.
This document summarizes different types of combustion chambers used in compression ignition (CI) engines. It describes direct injection combustion chambers like shallow depth, hemispherical, cylindrical, and toroidal chambers. It also describes indirect injection combustion chambers like swirl, pre-ignition, and air-cell chambers. Each type of chamber is briefly explained along with advantages it provides in fuel combustion. Direct injection chambers inject fuel directly into the cylinder while indirect injection chambers use a pre-chamber to improve combustion.
This document discusses spark ignition engines. It covers mixture requirements, fuel injection systems, stages of combustion including normal and abnormal combustion like knocking. Knocking occurs when pockets of air-fuel mixture explode outside of the normal combustion front. Factors that affect knocking include density factors, time factors, and composition factors. The document also discusses combustion chambers and their role in smooth engine operation and high power output.
The document describes a six-stroke engine, which has two additional strokes compared to a four-stroke engine. The additional strokes allow for water injection after the exhaust stroke, which vaporizes and drives the piston for another power stroke. This provides increased efficiency of 40% over a four-stroke engine due to capturing wasted heat. The document outlines the working principle, modifications needed to the engine like materials and cam shaft design, advantages like reduced emissions and fuel consumption, and limitations such as starting problems.
The document discusses a battery ignition system for internal combustion engines. It consists of a battery, ignition switch, ballast resistor, ignition coil, contact breaker, capacitor, distributor, and spark plug. The ignition coil steps up the low voltage from the battery to a high voltage spark. When the contact points open, the current flows through the capacitor to induce a collapsing magnetic field in the coil, creating a high voltage spark in the spark plug. Battery ignition systems have advantages like fewer moving parts requiring less maintenance and improved fuel efficiency. Disadvantages include issues from contact point arcing over time. It is commonly used in modern vehicle and industrial engines.
A carburetor mixes air and fuel for combustion in an internal combustion engine. It contains several main parts including a venturi, float chamber, nozzles, and throttle valve. A carburetor uses venturi suction to draw fuel from the float chamber and mix it with air to supply the engine. The main types are updraft, downdraft, and horizontal based on airflow direction. Carburetors provide fuel metering and air-fuel ratio control for engines. While simpler than fuel injection, carburetors are less precise at mixing fuel and air.
Vehicular traffic is a major contributor to environmental pollution today. Nitrogen oxides (NOx) emitted from vehicle exhaust are particularly harmful, as they are constituents of smog and contribute to acid rain and respiratory illnesses. Exhaust gas recirculation (EGR) is an effective method to reduce NOx emissions from diesel engines by recirculating exhaust gas into the engine cylinders, lowering peak combustion temperatures and reducing available oxygen. This intermixing of exhaust gas with intake air through an EGR valve and cooler system achieves NOx reductions of 5-30% while improving engine efficiency and life.
PRESSURIZED FLUIDIZED BED COMBUSTION BOILERKRUNAL RAVAL
In PFBC, the combustor and hot gas cyclones are all enclosed in a pressure vessel. Both coal and sorbent have to be fed across the pressure boundary, and
similar provision for ash removal is necessary. For hard coal applications, the coal and limestone can be crushed together, and then fed as a paste, with 25% water. As with atmospheric FBC (CFBC or BFBC), the combustion temperature between 800-900°C has the advantage that NOx formation is less. SO2
emissions can be reduced by the injection of a sorbent, and its subsequent removal with the ash.
The document summarizes key aspects of steam turbines. It begins by explaining that a steam turbine converts the heat energy of steam into kinetic energy and then rotational energy to generate power. It then describes the basic Rankine cycle used in steam turbine power plants.
The main body explains the principles of operation for impulse and reaction turbines. In an impulse turbine, steam expands within nozzles and does not change pressure as it moves over blades, while in a reaction turbine steam pressure gradually drops as it expands over fixed and moving blades.
Finally, it discusses methods to improve efficiency, such as compounding and reheat, where dividing the expansion process into multiple stages separated by reheaters increases overall efficiency compared to a single stage by
Valve timing diagram for - four stroke & two stroke - diesel & petrol engine ...Satish Patel
The document discusses valve timing diagrams for 4-stroke and 2-stroke petrol and diesel engines. It provides details on the opening and closing of intake, exhaust, and transfer ports during each stroke. For 4-stroke engines, it describes the intake, compression, power, and exhaust strokes. The actual valve timings are given for 4-stroke diesel and petrol engines. For 2-stroke engines, it explains the expansion and compression strokes and provides the actual valve timings. Diagrams are included to illustrate the valve timing events during each stage of the engine cycles.
2b9fc module iii steering system_ part-ii (2)Tanvi Gautam
The document discusses steering systems and components. It describes steering linkages used in vehicles with rigid axle front suspensions and independent front suspensions. It also discusses different types of steering gears like rack and pinion gears, and how power steering systems and electronic power steering systems work. It provides details on Davis steering mechanism and Ackerman steering mechanism.
This document summarizes a seminar presentation on a six-stroke engine. It describes how a six-stroke engine works, providing six piston movements per cycle through the use of a second piston or by capturing waste heat for an additional power stroke. The document outlines the history of six-stroke engine development and describes several notable six-stroke engine designs, including those that use steam or air from waste heat for a second power stroke and those that use an opposed secondary piston. It also discusses modifications made to convert a four-stroke engine to a six-stroke design.
A gas turbine power plant works by compressing air which is then mixed with fuel and ignited in a combustion chamber. This produces hot gases that spin a turbine, generating power. The key components are the compressor, combustion chamber, and turbine. The compressed air and added fuel are burned in the combustion chamber. This turns the turbine, powering the compressor and external loads. Gas turbines are used for power generation and to drive aircraft, ships, pumps and other machinery.
Here You Can get best Notes of WORKING OF MAGNETO IGNITION SYSTEM
If you have any questions or Doubt , you can contact me
Contact- technologyscienceand285@gmail.com
This document discusses different combustion chamber designs for compression ignition (CI) engines. It describes direct injection (DI) and indirect injection (IDI) combustion chambers. DI chambers have the entire combustion space located in the cylinder and include open chambers with different cavity shapes. IDI chambers divide the combustion space between the cylinder and cylinder head. Types of IDI chambers include swirl chambers, precombustion chambers, and air cell chambers. The document also discusses mixture formation methods and provides details on the MAN combustion chamber design.
Thermal power plants operate using the Rankine cycle. They typically include a coal conveyor to transport coal, a pulverizer to grind the coal, a boiler to heat water into steam using the pulverized coal, a turbine turned by the steam, and a generator turned by the turbine to produce electricity. Proper site planning is important to minimize environmental impacts when locating intake and emissions sources. Water tube boilers allow higher pressures and quicker response compared to fire tube boilers. Fly ash is a byproduct of coal combustion that is often reused in applications like cement production.
The Animated 4 Cycle Internal Combustion EngineChris Coggon
The document provides instructions for starting and stopping an engine by listing the steps "ENGINE START", "Next", and "STOP ENGINE START". It does not provide any other context or details about the engine or steps.
This document discusses steam turbines, including their working principles and different types. It describes how potential energy from steam is converted to kinetic energy and then mechanical energy in a turbine. There are two main types of turbines - impulse turbines and reaction turbines. Impulse turbines expand steam fully in nozzles before it hits moving blades, while reaction turbines feature continuous expansion over fixed and moving blades. The document also discusses methods of compounding turbines to reduce rotor speed, including velocity, pressure, and pressure-velocity compounding.
Valve timing is the precise timing of the opening and closing of valves in an internal combustion engine. It is controlled by the camshaft and can be varied by modifying the camshaft or using variable valve timing. With traditional fixed valve timing, engines experience a period of valve overlap when both intake and exhaust valves are open simultaneously. Variable valve timing uses computer control and oil pressure to advance or retard cam timing while the engine is running, changing valve duration, overlap, and sometimes lift. It has been implemented in many Japanese and European engines since the 1980s-1990s and more recently in some American engines.
The Velox boiler operates on the principle that heat transfer rate increases when gas velocity exceeds the speed of sound. This allows the Velox boiler to generate steam at a higher rate without increasing the boiler size. The Velox boiler works as a basic heat exchanger, where compressed air from a gas turbine passes through combustion chambers and fire tubes at supersonic speeds, transferring heat to water circulating at high speeds in evaporator tubes. The high-speed water circulation results in efficient heat transfer and mixing of water and steam, which is then separated before the steam is superheated and used for power generation. The flue gases also pass through superheater tubes before rotating the gas turbine and transferring remaining heat in an economizer.
This document provides an overview of six-stroke engine designs that aim to improve efficiency over traditional four-stroke engines. It describes the working principles of various six-stroke engine types, including single piston designs by Griffin, Bajulaz, Crower, and Velozeta as well as opposed piston designs like the Beare head engine. The document also discusses the modifications needed to convert a conventional engine to a six-stroke design and analyzes the advantages of six-stroke engines like reduced fuel consumption and emissions.
The document discusses different types of combustion chambers used in spark ignition and compression ignition engines. It describes the T-head, L-head, I-head (overhead valve), and F-head combustion chamber designs for SI engines. The T-head and L-head designs were used early on but have disadvantages like susceptibility to detonation. The I-head design locates both valves in the cylinder head and allows higher compression ratios. The document also discusses open injection and indirect injection combustion chamber designs for CI engines and factors considered in the combustion chamber design like efficiency, emissions and fuel usage.
The document discusses different types of combustion chamber designs used in internal combustion engines. It describes T-head, L-head, overhead valve (I-head), and F-head combustion chamber designs. The T-head design uses separate camshafts but has low compression ratios. The L-head is a modified T-head but uses a single camshaft. The overhead valve design allows for higher compression ratios and better engine performance. Within the overhead valve design, bath tub and wedge shaped combustion chambers are discussed. The F-head design has valves in both the head and block. A divided combustion chamber uses a smaller pre-chamber for initial combustion before flames spread to the main chamber.
The document describes a six-stroke engine, which has two additional strokes compared to a four-stroke engine. The additional strokes allow for water injection after the exhaust stroke, which vaporizes and drives the piston for another power stroke. This provides increased efficiency of 40% over a four-stroke engine due to capturing wasted heat. The document outlines the working principle, modifications needed to the engine like materials and cam shaft design, advantages like reduced emissions and fuel consumption, and limitations such as starting problems.
The document discusses a battery ignition system for internal combustion engines. It consists of a battery, ignition switch, ballast resistor, ignition coil, contact breaker, capacitor, distributor, and spark plug. The ignition coil steps up the low voltage from the battery to a high voltage spark. When the contact points open, the current flows through the capacitor to induce a collapsing magnetic field in the coil, creating a high voltage spark in the spark plug. Battery ignition systems have advantages like fewer moving parts requiring less maintenance and improved fuel efficiency. Disadvantages include issues from contact point arcing over time. It is commonly used in modern vehicle and industrial engines.
A carburetor mixes air and fuel for combustion in an internal combustion engine. It contains several main parts including a venturi, float chamber, nozzles, and throttle valve. A carburetor uses venturi suction to draw fuel from the float chamber and mix it with air to supply the engine. The main types are updraft, downdraft, and horizontal based on airflow direction. Carburetors provide fuel metering and air-fuel ratio control for engines. While simpler than fuel injection, carburetors are less precise at mixing fuel and air.
Vehicular traffic is a major contributor to environmental pollution today. Nitrogen oxides (NOx) emitted from vehicle exhaust are particularly harmful, as they are constituents of smog and contribute to acid rain and respiratory illnesses. Exhaust gas recirculation (EGR) is an effective method to reduce NOx emissions from diesel engines by recirculating exhaust gas into the engine cylinders, lowering peak combustion temperatures and reducing available oxygen. This intermixing of exhaust gas with intake air through an EGR valve and cooler system achieves NOx reductions of 5-30% while improving engine efficiency and life.
PRESSURIZED FLUIDIZED BED COMBUSTION BOILERKRUNAL RAVAL
In PFBC, the combustor and hot gas cyclones are all enclosed in a pressure vessel. Both coal and sorbent have to be fed across the pressure boundary, and
similar provision for ash removal is necessary. For hard coal applications, the coal and limestone can be crushed together, and then fed as a paste, with 25% water. As with atmospheric FBC (CFBC or BFBC), the combustion temperature between 800-900°C has the advantage that NOx formation is less. SO2
emissions can be reduced by the injection of a sorbent, and its subsequent removal with the ash.
The document summarizes key aspects of steam turbines. It begins by explaining that a steam turbine converts the heat energy of steam into kinetic energy and then rotational energy to generate power. It then describes the basic Rankine cycle used in steam turbine power plants.
The main body explains the principles of operation for impulse and reaction turbines. In an impulse turbine, steam expands within nozzles and does not change pressure as it moves over blades, while in a reaction turbine steam pressure gradually drops as it expands over fixed and moving blades.
Finally, it discusses methods to improve efficiency, such as compounding and reheat, where dividing the expansion process into multiple stages separated by reheaters increases overall efficiency compared to a single stage by
Valve timing diagram for - four stroke & two stroke - diesel & petrol engine ...Satish Patel
The document discusses valve timing diagrams for 4-stroke and 2-stroke petrol and diesel engines. It provides details on the opening and closing of intake, exhaust, and transfer ports during each stroke. For 4-stroke engines, it describes the intake, compression, power, and exhaust strokes. The actual valve timings are given for 4-stroke diesel and petrol engines. For 2-stroke engines, it explains the expansion and compression strokes and provides the actual valve timings. Diagrams are included to illustrate the valve timing events during each stage of the engine cycles.
2b9fc module iii steering system_ part-ii (2)Tanvi Gautam
The document discusses steering systems and components. It describes steering linkages used in vehicles with rigid axle front suspensions and independent front suspensions. It also discusses different types of steering gears like rack and pinion gears, and how power steering systems and electronic power steering systems work. It provides details on Davis steering mechanism and Ackerman steering mechanism.
This document summarizes a seminar presentation on a six-stroke engine. It describes how a six-stroke engine works, providing six piston movements per cycle through the use of a second piston or by capturing waste heat for an additional power stroke. The document outlines the history of six-stroke engine development and describes several notable six-stroke engine designs, including those that use steam or air from waste heat for a second power stroke and those that use an opposed secondary piston. It also discusses modifications made to convert a four-stroke engine to a six-stroke design.
A gas turbine power plant works by compressing air which is then mixed with fuel and ignited in a combustion chamber. This produces hot gases that spin a turbine, generating power. The key components are the compressor, combustion chamber, and turbine. The compressed air and added fuel are burned in the combustion chamber. This turns the turbine, powering the compressor and external loads. Gas turbines are used for power generation and to drive aircraft, ships, pumps and other machinery.
Here You Can get best Notes of WORKING OF MAGNETO IGNITION SYSTEM
If you have any questions or Doubt , you can contact me
Contact- technologyscienceand285@gmail.com
This document discusses different combustion chamber designs for compression ignition (CI) engines. It describes direct injection (DI) and indirect injection (IDI) combustion chambers. DI chambers have the entire combustion space located in the cylinder and include open chambers with different cavity shapes. IDI chambers divide the combustion space between the cylinder and cylinder head. Types of IDI chambers include swirl chambers, precombustion chambers, and air cell chambers. The document also discusses mixture formation methods and provides details on the MAN combustion chamber design.
Thermal power plants operate using the Rankine cycle. They typically include a coal conveyor to transport coal, a pulverizer to grind the coal, a boiler to heat water into steam using the pulverized coal, a turbine turned by the steam, and a generator turned by the turbine to produce electricity. Proper site planning is important to minimize environmental impacts when locating intake and emissions sources. Water tube boilers allow higher pressures and quicker response compared to fire tube boilers. Fly ash is a byproduct of coal combustion that is often reused in applications like cement production.
The Animated 4 Cycle Internal Combustion EngineChris Coggon
The document provides instructions for starting and stopping an engine by listing the steps "ENGINE START", "Next", and "STOP ENGINE START". It does not provide any other context or details about the engine or steps.
This document discusses steam turbines, including their working principles and different types. It describes how potential energy from steam is converted to kinetic energy and then mechanical energy in a turbine. There are two main types of turbines - impulse turbines and reaction turbines. Impulse turbines expand steam fully in nozzles before it hits moving blades, while reaction turbines feature continuous expansion over fixed and moving blades. The document also discusses methods of compounding turbines to reduce rotor speed, including velocity, pressure, and pressure-velocity compounding.
Valve timing is the precise timing of the opening and closing of valves in an internal combustion engine. It is controlled by the camshaft and can be varied by modifying the camshaft or using variable valve timing. With traditional fixed valve timing, engines experience a period of valve overlap when both intake and exhaust valves are open simultaneously. Variable valve timing uses computer control and oil pressure to advance or retard cam timing while the engine is running, changing valve duration, overlap, and sometimes lift. It has been implemented in many Japanese and European engines since the 1980s-1990s and more recently in some American engines.
The Velox boiler operates on the principle that heat transfer rate increases when gas velocity exceeds the speed of sound. This allows the Velox boiler to generate steam at a higher rate without increasing the boiler size. The Velox boiler works as a basic heat exchanger, where compressed air from a gas turbine passes through combustion chambers and fire tubes at supersonic speeds, transferring heat to water circulating at high speeds in evaporator tubes. The high-speed water circulation results in efficient heat transfer and mixing of water and steam, which is then separated before the steam is superheated and used for power generation. The flue gases also pass through superheater tubes before rotating the gas turbine and transferring remaining heat in an economizer.
This document provides an overview of six-stroke engine designs that aim to improve efficiency over traditional four-stroke engines. It describes the working principles of various six-stroke engine types, including single piston designs by Griffin, Bajulaz, Crower, and Velozeta as well as opposed piston designs like the Beare head engine. The document also discusses the modifications needed to convert a conventional engine to a six-stroke design and analyzes the advantages of six-stroke engines like reduced fuel consumption and emissions.
The document discusses different types of combustion chambers used in spark ignition and compression ignition engines. It describes the T-head, L-head, I-head (overhead valve), and F-head combustion chamber designs for SI engines. The T-head and L-head designs were used early on but have disadvantages like susceptibility to detonation. The I-head design locates both valves in the cylinder head and allows higher compression ratios. The document also discusses open injection and indirect injection combustion chamber designs for CI engines and factors considered in the combustion chamber design like efficiency, emissions and fuel usage.
The document discusses different types of combustion chamber designs used in internal combustion engines. It describes T-head, L-head, overhead valve (I-head), and F-head combustion chamber designs. The T-head design uses separate camshafts but has low compression ratios. The L-head is a modified T-head but uses a single camshaft. The overhead valve design allows for higher compression ratios and better engine performance. Within the overhead valve design, bath tub and wedge shaped combustion chambers are discussed. The F-head design has valves in both the head and block. A divided combustion chamber uses a smaller pre-chamber for initial combustion before flames spread to the main chamber.
The document provides an overview of a seminar presentation on a six-stroke internal combustion engine. It includes an abstract, introduction, working principles, types of six-stroke engines, modifications made to convert a four-stroke engine to six-stroke, advantages such as reduced emissions and increased efficiency, and limitations. The six-stroke engine aims to extract more energy from the combustion process through adding an additional power stroke, utilizing the wasted heat from the four-stroke cycle. It functions by injecting water during the additional power stroke to generate steam for forcing the piston downward.
- BOG compressors used in LNG terminals and on LNG carriers operate in demanding cryogenic environments where availability and reliability are paramount. Unplanned downtime is not an option.
- A new technology called the Free Floating Piston is introduced that provides enhanced availability and reliability for horizontal reciprocating compressors used in LNG applications. It creates a hydrostatic gas bearing to eliminate wear on rider rings.
- A case study showed the Free Floating Piston technology increased the mean time between maintenance on a compressor from 4000-6000 hours to over 16,000 hours, significantly reducing downtime and maintenance costs.
Study and Analysis of Six Stroke EngineIJERA Editor
Six Stroke engine, the name itself indicates a cycle of six strokes out of which two are useful power strokes. According to its mechanical design, the six-stroke engine with external and internal combustion and double flow is similar to the actual internal reciprocating combustion engine. However, it differentiates itself entirely, due to its thermodynamic cycle and a modified cylinder head with two supplementary chambers: combustion and an air heating chamber, both independent from the cylinder. In this the cylinder and the combustion chamber are separated which gives more freedom for design analysis. In addition to the two valves in the four stroke engine two more valves are incorporated which are operated by a piston arrangement. The Six Stroke is thermodynamically more efficient because the change in volume of the power stroke is greater than the intake stroke and the compression stroke. The main advantages of six stroke engine includes reduction in fuel consumption by 40%, two power strokes in the six stroke cycle, dramatic reduction in pollution, adaptability to multi fuel operation. Six stroke engine’s adoption by the automobile industry would have a tremendous impact on the environment and world economy .
This document summarizes the key details of Hyundai-Kia's new 1.0L three-cylinder gasoline engine. The engine was designed with fuel efficiency and emissions reductions in mind to meet increasing regulations. A three-cylinder configuration was chosen over a two or four-cylinder design based on its balance of performance, fuel economy, noise vibration and harshness, costs, and other factors. The engine utilizes various technologies including an aluminum alloy block, offset crankshaft, low-friction bearings, and dual continuously variable valve timing to achieve high power and torque while improving fuel efficiency.
1. There are multiple arrangements of combustion chambers used for different applications, including a single large chamber for heavy industrial power plants, multiple chambers for aircraft, and annular chambers best suited for compressors of axial flow type.
2. Combustion chambers must blend air and fuel efficiently, control the burning of large amounts of fuel and air, dampen hot combustion gases, and ensure expanded air with minimum pressure loss and maximum heat release.
3. Industrial combustion chambers are larger than aircraft chambers to allow longer residence times inside when fuel quality is poor and lower pressure drops due to lower flow velocities.
This document discusses six-stroke engines as a more efficient alternative to four-stroke engines. It describes two main types of six-stroke engine designs: single piston and opposed piston. Several single piston engine examples are provided, including the Griffin engine which uses a heated vaporizer to improve fuel efficiency. The Bajulaz engine is also described, which uses two additional chambers above each cylinder for combustion and air preheating. Benefits over four-stroke engines include increased power and torque, lower emissions, and simpler design. However, six-stroke engines also have increased complexity and cost compared to four-stroke engines. The document suggests they may be best suited for applications like racing vehicles, heavy machinery, and stationary engines.
The document discusses combustion chamber design and types for gas turbine engines. It describes the key requirements for combustion chambers including low weight, stable and efficient combustion over operating conditions, and uniform temperature distribution. It classifies combustion chambers as can, can-annular, or annular and describes the characteristics and advantages/disadvantages of each type. Important factors for combustion chamber design are maintaining suitable turbine inlet temperatures, stable combustion over a range of operating conditions, and controlling emissions.
Gas turbine design aims to increase firing temperature, compression ratio, and mass flow to improve output and efficiency. The most critical components are the combustion chambers and turbine nozzles and buckets, which require specialized alloys and coatings to withstand high temperatures. Combined cycle power plants pair one or more gas turbines with a heat recovery steam generator and steam turbine to achieve over 50% efficiency. They are available in sizes from 50-500MW.
The document discusses the design objectives and history of the hemispherical or "HEMI" engine. Key points include:
- HEMI engines aim to maximize power extraction from each combustion stroke by burning all fuel, having maximum cylinder pressure occur at the optimal crankshaft angle, and minimizing losses.
- Chrysler introduced the HEMI design in the 1950s to increase power without higher compression ratios. It provided better airflow and efficiency than flathead designs.
- Advantages of HEMI engines include smaller combustion chamber surface area, more room for larger intake/exhaust valves, and centrally-located spark plugs. However, disadvantages include sensitivity to fuel octane and inability to use more
The document discusses various topics related to spark ignition engines, including:
- Air-fuel ratio requirements and how they affect power output and fuel consumption. Carburetor design factors like venturi size and fuel jet size that are used to achieve the proper air-fuel ratio.
- The different stages of combustion in spark ignition engines including normal combustion and abnormal combustion like knocking. Factors that influence knocking like fuel composition, engine speed and temperature.
- Designs of common combustion chambers and their advantages in providing smooth engine operation and high power output.
- An overview of carburetor components and functions including the float chamber, venturi, throttle and choke. Principles of carburetion and vapor
This document provides an introduction to afterburners, including their components and design requirements. It discusses how afterburners work to augment thrust by injecting additional fuel downstream of the turbine. Key components include a diffuser, fuel injection system, igniter, flame holders, cooling liners, and variable area nozzle. The document describes the purpose and functioning of each component. It also outlines specific design goals for afterburners such as high temperature rise, low losses, wide temperature modulation capability, and avoidance of combustion instabilities.
Turbochargers increase an engine's efficiency and power output by forcing extra compressed air into the combustion chamber. They have been used since the early 1900s but became more common in automobiles following the 1973 oil crisis. A turbocharger consists of a compressor and turbine connected by a shaft, with the turbine powered by exhaust gases that spin the compressor and force more air into the engine cylinders. Proper maintenance like regular oil changes is important to prevent failures and extend the life of turbocharger components exposed to high temperatures and pressures.
This document summarizes a technical seminar presentation on a six-stroke engine by Chethan MR, an undergraduate student at C. Byregowda Institute of Technology in Kolar, India. The presentation covered the introduction, abstract, methodology, working principle, advantages, and disadvantages of a six-stroke engine. A six-stroke engine aims to improve efficiency and reduce emissions compared to four-stroke engines by adding two additional strokes - an additional compression and power stroke - to the piston cycle. Modifications are made to the crankshaft, camshaft, and cam followers to accommodate the additional strokes.
Combustion Chamber for Compression Ignition EnginesKaushal Patel
Description of various types of combustion chambers for compression ignition engines, various types of swirls, primary combustion considerations, advantages and disadvantages of various types of swirls and combustion chambers.
Article written by Xavier D’Hubert, Combustion Consultant for Global Cement Magazine.
In this article each cement burner OEM was given the opportunity to present the main features of its burners as well as provide insight into design concepts and their evolution.
The emphasis is on the latest offering of each OEM, even though several still sell burners from previous generations. As not all OEMs responded, the exercise has been completed using information found in the available literature. For more information on the evolution of burner design trends, see the February 2017 issue of Global Cement Magazine.
This document provides an overview of gas turbine engines and their components. It discusses the fundamentals of gas turbine engines including the Brayton cycle and basic components like compressors, combustion chambers, and nozzles. Regarding compressors, it describes the advantages and disadvantages of radial/centrifugal and axial flow compressors. For combustion chambers, it discusses different chamber types (can, can-annular, annular) and factors affecting combustor design like temperature, stability, and pollution control. It also provides information on supersonic combustion challenges. Finally, it provides an introduction to nozzles and their objectives in jet propulsion.
Rainfall intensity duration frequency curve statistical analysis and modeling...bijceesjournal
Using data from 41 years in Patna’ India’ the study’s goal is to analyze the trends of how often it rains on a weekly, seasonal, and annual basis (1981−2020). First, utilizing the intensity-duration-frequency (IDF) curve and the relationship by statistically analyzing rainfall’ the historical rainfall data set for Patna’ India’ during a 41 year period (1981−2020), was evaluated for its quality. Changes in the hydrologic cycle as a result of increased greenhouse gas emissions are expected to induce variations in the intensity, length, and frequency of precipitation events. One strategy to lessen vulnerability is to quantify probable changes and adapt to them. Techniques such as log-normal, normal, and Gumbel are used (EV-I). Distributions were created with durations of 1, 2, 3, 6, and 24 h and return times of 2, 5, 10, 25, and 100 years. There were also mathematical correlations discovered between rainfall and recurrence interval.
Findings: Based on findings, the Gumbel approach produced the highest intensity values, whereas the other approaches produced values that were close to each other. The data indicates that 461.9 mm of rain fell during the monsoon season’s 301st week. However, it was found that the 29th week had the greatest average rainfall, 92.6 mm. With 952.6 mm on average, the monsoon season saw the highest rainfall. Calculations revealed that the yearly rainfall averaged 1171.1 mm. Using Weibull’s method, the study was subsequently expanded to examine rainfall distribution at different recurrence intervals of 2, 5, 10, and 25 years. Rainfall and recurrence interval mathematical correlations were also developed. Further regression analysis revealed that short wave irrigation, wind direction, wind speed, pressure, relative humidity, and temperature all had a substantial influence on rainfall.
Originality and value: The results of the rainfall IDF curves can provide useful information to policymakers in making appropriate decisions in managing and minimizing floods in the study area.
Null Bangalore | Pentesters Approach to AWS IAMDivyanshu
#Abstract:
- Learn more about the real-world methods for auditing AWS IAM (Identity and Access Management) as a pentester. So let us proceed with a brief discussion of IAM as well as some typical misconfigurations and their potential exploits in order to reinforce the understanding of IAM security best practices.
- Gain actionable insights into AWS IAM policies and roles, using hands on approach.
#Prerequisites:
- Basic understanding of AWS services and architecture
- Familiarity with cloud security concepts
- Experience using the AWS Management Console or AWS CLI.
- For hands on lab create account on [killercoda.com](https://killercoda.com/cloudsecurity-scenario/)
# Scenario Covered:
- Basics of IAM in AWS
- Implementing IAM Policies with Least Privilege to Manage S3 Bucket
- Objective: Create an S3 bucket with least privilege IAM policy and validate access.
- Steps:
- Create S3 bucket.
- Attach least privilege policy to IAM user.
- Validate access.
- Exploiting IAM PassRole Misconfiguration
-Allows a user to pass a specific IAM role to an AWS service (ec2), typically used for service access delegation. Then exploit PassRole Misconfiguration granting unauthorized access to sensitive resources.
- Objective: Demonstrate how a PassRole misconfiguration can grant unauthorized access.
- Steps:
- Allow user to pass IAM role to EC2.
- Exploit misconfiguration for unauthorized access.
- Access sensitive resources.
- Exploiting IAM AssumeRole Misconfiguration with Overly Permissive Role
- An overly permissive IAM role configuration can lead to privilege escalation by creating a role with administrative privileges and allow a user to assume this role.
- Objective: Show how overly permissive IAM roles can lead to privilege escalation.
- Steps:
- Create role with administrative privileges.
- Allow user to assume the role.
- Perform administrative actions.
- Differentiation between PassRole vs AssumeRole
Try at [killercoda.com](https://killercoda.com/cloudsecurity-scenario/)
An improved modulation technique suitable for a three level flying capacitor ...IJECEIAES
This research paper introduces an innovative modulation technique for controlling a 3-level flying capacitor multilevel inverter (FCMLI), aiming to streamline the modulation process in contrast to conventional methods. The proposed
simplified modulation technique paves the way for more straightforward and
efficient control of multilevel inverters, enabling their widespread adoption and
integration into modern power electronic systems. Through the amalgamation of
sinusoidal pulse width modulation (SPWM) with a high-frequency square wave
pulse, this controlling technique attains energy equilibrium across the coupling
capacitor. The modulation scheme incorporates a simplified switching pattern
and a decreased count of voltage references, thereby simplifying the control
algorithm.
Software Engineering and Project Management - Introduction, Modeling Concepts...Prakhyath Rai
Introduction, Modeling Concepts and Class Modeling: What is Object orientation? What is OO development? OO Themes; Evidence for usefulness of OO development; OO modeling history. Modeling
as Design technique: Modeling, abstraction, The Three models. Class Modeling: Object and Class Concept, Link and associations concepts, Generalization and Inheritance, A sample class model, Navigation of class models, and UML diagrams
Building the Analysis Models: Requirement Analysis, Analysis Model Approaches, Data modeling Concepts, Object Oriented Analysis, Scenario-Based Modeling, Flow-Oriented Modeling, class Based Modeling, Creating a Behavioral Model.
Advanced control scheme of doubly fed induction generator for wind turbine us...IJECEIAES
This paper describes a speed control device for generating electrical energy on an electricity network based on the doubly fed induction generator (DFIG) used for wind power conversion systems. At first, a double-fed induction generator model was constructed. A control law is formulated to govern the flow of energy between the stator of a DFIG and the energy network using three types of controllers: proportional integral (PI), sliding mode controller (SMC) and second order sliding mode controller (SOSMC). Their different results in terms of power reference tracking, reaction to unexpected speed fluctuations, sensitivity to perturbations, and resilience against machine parameter alterations are compared. MATLAB/Simulink was used to conduct the simulations for the preceding study. Multiple simulations have shown very satisfying results, and the investigations demonstrate the efficacy and power-enhancing capabilities of the suggested control system.
Embedded machine learning-based road conditions and driving behavior monitoringIJECEIAES
Car accident rates have increased in recent years, resulting in losses in human lives, properties, and other financial costs. An embedded machine learning-based system is developed to address this critical issue. The system can monitor road conditions, detect driving patterns, and identify aggressive driving behaviors. The system is based on neural networks trained on a comprehensive dataset of driving events, driving styles, and road conditions. The system effectively detects potential risks and helps mitigate the frequency and impact of accidents. The primary goal is to ensure the safety of drivers and vehicles. Collecting data involved gathering information on three key road events: normal street and normal drive, speed bumps, circular yellow speed bumps, and three aggressive driving actions: sudden start, sudden stop, and sudden entry. The gathered data is processed and analyzed using a machine learning system designed for limited power and memory devices. The developed system resulted in 91.9% accuracy, 93.6% precision, and 92% recall. The achieved inference time on an Arduino Nano 33 BLE Sense with a 32-bit CPU running at 64 MHz is 34 ms and requires 2.6 kB peak RAM and 139.9 kB program flash memory, making it suitable for resource-constrained embedded systems.
Applications of artificial Intelligence in Mechanical Engineering.pdfAtif Razi
Historically, mechanical engineering has relied heavily on human expertise and empirical methods to solve complex problems. With the introduction of computer-aided design (CAD) and finite element analysis (FEA), the field took its first steps towards digitization. These tools allowed engineers to simulate and analyze mechanical systems with greater accuracy and efficiency. However, the sheer volume of data generated by modern engineering systems and the increasing complexity of these systems have necessitated more advanced analytical tools, paving the way for AI.
AI offers the capability to process vast amounts of data, identify patterns, and make predictions with a level of speed and accuracy unattainable by traditional methods. This has profound implications for mechanical engineering, enabling more efficient design processes, predictive maintenance strategies, and optimized manufacturing operations. AI-driven tools can learn from historical data, adapt to new information, and continuously improve their performance, making them invaluable in tackling the multifaceted challenges of modern mechanical engineering.
Batteries -Introduction – Types of Batteries – discharging and charging of battery - characteristics of battery –battery rating- various tests on battery- – Primary battery: silver button cell- Secondary battery :Ni-Cd battery-modern battery: lithium ion battery-maintenance of batteries-choices of batteries for electric vehicle applications.
Fuel Cells: Introduction- importance and classification of fuel cells - description, principle, components, applications of fuel cells: H2-O2 fuel cell, alkaline fuel cell, molten carbonate fuel cell and direct methanol fuel cells.
Discover the latest insights on Data Driven Maintenance with our comprehensive webinar presentation. Learn about traditional maintenance challenges, the right approach to utilizing data, and the benefits of adopting a Data Driven Maintenance strategy. Explore real-world examples, industry best practices, and innovative solutions like FMECA and the D3M model. This presentation, led by expert Jules Oudmans, is essential for asset owners looking to optimize their maintenance processes and leverage digital technologies for improved efficiency and performance. Download now to stay ahead in the evolving maintenance landscape.
1. Unit 2. Combustion in SI Engines
Subject :- Applied Thermodynamics
Prepared By:- Prasad A Bojage
Department of Mechanical Engineering
04/25/19 SRES COE, Department of Mechanical Engg Prepared by Prasad A Bojage 1
2. BASIC REQUIREMENTS OF A GOOD COMBUSTION
CHAMBER
The basic requirements of a good combustion chamber
are to provide:
High power output
High thermal efficiency and low specific fuel
consumption
Smooth engine operation
Reduced exhaust pollutants
04/25/19 SRES COE, Department of Mechanical Engg Prepared by Prasad A Bojage 2
3. HIGHER POWER OUTPUT REQUIRES THE FOLLOWING
High compression ratio.
The compression ratio is limited by the phenomenon of
detonation.
Detonation depends on the design of combustion chamber
and fuel quality.
Any change in design that improves the anti-knock
characteristics of a combustion chamber permits the use of a
higher compression ratio which should result in higher
output and efficiency
04/25/19 SRES COE, Department of Mechanical Engg Prepared by Prasad A Bojage 3
4. Small or no excess air.
Complete utilization of the air – no dead pockets.
An optimum degree of turbulence. Turbulence is
induced by inlet flow configuration or ‘squish’. Squish
is the rapid ejection of gas trapped between the piston
and some flat or corresponding surface in the cylinder
head.
Turbulence induced by squish is preferable to inlet
turbulence since the volumetric efficiency not effected.
04/25/19 SRES COE, Department of Mechanical Engg Prepared by Prasad A Bojage 4
5. HIGH THERMAL EFFICIENCY REQUIRES THE
FOLLOWING:
High compression ratio: Already discussed.
A small heat loss during combustion. This is achieved
by having a compact combustion chamber which
provides small surface-volume ratio.
The other advantage of compact combustion chamber
is reduced flame travel a given turbulence, this reduces
the time of combustion and hence combustion time
loss
Good scavenging of the exhaust gases.
04/25/19 SRES COE, Department of Mechanical Engg Prepared by Prasad A Bojage 5
6. SMOOTH ENGINE OPERATION REQUIRES THE
FOLLOWING:
Moderate rate of pressure rise during combustion.
Absence of detonation which in turn means:
Compact combustion chamber, short distance of flame
travel from the sparking plug to the farthest point in the
combustion space. Pockets in which stagnant gas may
collect should be avoided.
Proper location of the spark plug and exhaust valve.
Satisfactory cooling of the spark plug points (to avoid pre
ignition) and of exhaust valve head which is the hottest
region of the combustion chamber.
04/25/19 SRES COE, Department of Mechanical Engg Prepared by Prasad A Bojage 6
7. DIFFERENT TYPES OF COMBUSTION CHAMBERS
1. T-head combustion chamber.
2. L-head combustion chamber.
3. I-head (or overhead valve) combustion chamber.
4. F-head combustion chamber
It may be noted that these chambers are designed to
obtain the objectives namely:
A high combustion rate at the start.
A high surface-to-volume ratio near the end of
burning.
A rather centrally located spark plug.
04/25/19 SRES COE, Department of Mechanical Engg Prepared by Prasad A Bojage 7
8. T Head Type Combustion chambers
This was first introduced by Ford Motor Corporation in
1908. This design has following disadvantages.
Requires two cam shafts (for actuating the in-let valve and
exhaust valve separately) by two cams mounted on the two
cam shafts.
Very prone to detonation. There was violent detonation
even at a compression ratio of 4. This is because the
average octane number in 1908 was about 40 -50.
04/25/19 SRES COE, Department of Mechanical Engg Prepared by Prasad A Bojage 8
9. L Head Type Combustion chambers
04/25/19 SRES COE, Department of Mechanical Engg Prepared by Prasad A Bojage 9
10. It is a modification of the T-head type of combustion
chamber. It provides the two values on the same side of the
cylinder, and the valves are operated through tappet by a
single camshaft.
This was first introduced by Ford motor in 1910-30 and was
quite popular for some time.
This design has an advantage both from manufacturing and
maintenance point of view
Advantages:
Valve mechanism is simple and easy to lubricate.
Detachable head easy to remove for cleaning and
decarburizing without disturbing either the valve gear or
main pipe work.
Valves of larger sizes can be provided.
04/25/19 SRES COE, Department of Mechanical Engg Prepared by Prasad A Bojage 10
11. Disadvantages:
Lack of turbulence as the air had to take two right angle
turns to enter the cylinder and in doing so much initial
velocity is lost.
Extremely prone to detonation due to large flame length
and slow combustion due to lack of turbulence.
More surface-to-volume ratio and therefore more heat
loss.
Extremely sensitive to ignition timing due to slow
combustion process
Valve size restricted.
Thermal failure in cylinder block also. In I-head engine
the thermal failure is confined to cylinder head only
04/25/19 SRES COE, Department of Mechanical Engg Prepared by Prasad A Bojage 11
12. RICARDO’S TURBULENT HEAD– SIDE VALVE
COMBUSTION CHAMBER
Ricardo developed this head in 1919. His main objective
was to obtain fast flame speed and reduce knock in L
design. In Ricardo’s design the main body of combustion
chamber was concentrated over the valves, leaving slightly
restricted passage communicating with cylinder.
04/25/19 SRES COE, Department of Mechanical Engg Prepared by Prasad A Bojage 12
13. Advantages:
Additional turbulence during compression stroke is
possible as gases are forced back through the passage.
By varying throat area of passage designed degree of
additional turbulence is possible.
This design ensures a more homogeneous mixture by
scoring away the layer of stagnant gas clinging to chamber
wall. Both the above factors increase the flame speed and
thus the performance.
Deign make engine relatively insensitive to timing of spark
due to fast combustion
Higher engine speed is possible due to increased
turbulence
04/25/19 SRES COE, Department of Mechanical Engg Prepared by Prasad A Bojage 13
14. Ricardo’s design reduced the tendency to knock by
shortening length of effective flame travel by bringing that
portion of head which lay over the further side of piston
into as close a contact as possible with piston crown.
This design reduces length of flame travel by placing the
spark plug in the centre of effective combustion space.
04/25/19 SRES COE, Department of Mechanical Engg Prepared by Prasad A Bojage 14
15. Disadvantages :
With compression ratio of 6, normal speed of burning
increases and turbulent head tends to become over
turbulent and rate of pressure rise becomes too rapid leads
to rough running and high heat losses.
To overcome the above problem, Ricardo decreased the
areas of passage at the expense of reducing the clearance
volume and restricting the size of valves. This reduced
breathing capacity of engine, therefore these types of
chambers are not suitable for engine with high
compression ratio.
04/25/19 SRES COE, Department of Mechanical Engg Prepared by Prasad A Bojage 15
16. Over head valve or I head combustion chamber
The disappearance of the side valve or L-head design was
inevitable at high compression ratio of 8 : 1 because of the
lack of space in the combustion chamber to accommodate
the valves. Diesel engines, with high compression ratios,
invariably used overhead valve design.
Since 1950 or so mostly overhead valve combustion
chambers are used. This type of combustion chamber has
both the inlet valve and the exhaust valve located in the
cylinder head. An overhead engine is superior to side valve
engine at high compression ratios
04/25/19 SRES COE, Department of Mechanical Engg Prepared by Prasad A Bojage 16
17. The overhead valve engine is superior to side valve or
Lhead engine at high compression ratios, for the following
reasons:
Lower pumping losses and higher volumetric efficiency
from better breathing of the engine from larger valves or
valve lifts and more direct passageways.
Less distance for the flame to travel and therefore greater
freedom from knock, or in other words, lower octane
requirements.
Less force on the head bolts and therefore less possibility
of leakage (of compression gases or jacket water). The
projected area of a side valve combustion chamber is
inevitably greater than that of an overhead valve chamber.
04/25/19 SRES COE, Department of Mechanical Engg Prepared by Prasad A Bojage 17
18. Removal of the hot exhaust valve from the block to the
head, thus confining heat failures to the head. Absence of
exhaust valve from block also results in more uniform
cooling of cylinder and piston.
Lower surface-volume ratio and, therefore, less heat loss
and less air pollution.
Easier to cast and hence lower casting cost
04/25/19 SRES COE, Department of Mechanical Engg Prepared by Prasad A Bojage 18
19. Two important designs of overhead valve combustion
chambers are used .
Bath Tub Combustion Chamber. This is simple and
mechanically convenient form. This consists of an oval
shaped chamber with both valves mounted vertically
overhead and with the spark plug at the side. The main
draw back of this design is both valves are placed in a
single row along the cylinder block. This limits the
breathing capacity of engine, unless the overall length is
increased. However, modern engine manufactures
overcome this problem by using unity ratio for stroke and
bore size.
04/25/19 SRES COE, Department of Mechanical Engg Prepared by Prasad A Bojage 19
20. 04/25/19 SRES COE, Department of Mechanical Engg Prepared by Prasad A Bojage 20
21. Wedge Type Combustion Chamber.
In this design slightly inclined valves are used. This design
also has given very satisfactory performance. A modern
wedge type design can be seen in for Plymouth V-8
engine. It has a stoke of 99 mm and bore of 84mm with
compression ratio 9:1
04/25/19 SRES COE, Department of Mechanical Engg Prepared by Prasad A Bojage 21
22. F- Head combustion chamber
In such a combustion chamber one valve is in head and
other in the block. This design is a compromise between
L-head and I-head combustion chambers. One of the most
Fhead engines (wedge type) is the one used by the Rover
Company for several years. Another successful design of
this type of chamber is that used in Willeys jeeps
04/25/19 SRES COE, Department of Mechanical Engg Prepared by Prasad A Bojage 22
23. Its advantages are :
High volumetric efficiency
Maximum compression ratio for fuel of given octane
rating
High thermal efficiency
It can operate on leaner air-fuel ratios without
misfiring.
The drawback
This design is the complex mechanism for operation
of valves and expensive
special shaped piston.
04/25/19 SRES COE, Department of Mechanical Engg Prepared by Prasad A Bojage 23
25. In this type of chambers usually with about 80
percent of the clearance volume in the main chamber
above the piston and about 20 percent of the volume
as a secondary chamber.
Main chamber is connected to secondary chamber
through a small orifice Combustion is started in the
small secondary chamber.
As the gases in secondary chambers are consumed by
combustion, pressure rises and flaming gas expands
back through orifice and act as torch ignition for main
chamber.
04/25/19 SRES COE, Department of Mechanical Engg Prepared by Prasad A Bojage 25
26. Secondary chamber has high swirl and designed to
handle rich mixture. The rich mixture with very high
swirl in secondary chamber will ignite readily and
burn very quickly.
The flame gas expands through orifice and ignites the
lean mixture in the main chamber. The net result is
an engine that has good ignition and combustion and
yet operates mostly lean to give good fuel economy
04/25/19 SRES COE, Department of Mechanical Engg Prepared by Prasad A Bojage 26
27. Summary
04/25/19
SRES COE, Department of Mechanical Engg
Prepared by Prasad A Bojage 27
SI Engines Parameters
Combustion Homogenous Combustion
Ignition Spark Ignited
A/F Ratio 9:1 to 20:1
Fuel System Carburetor, MPFI, GDI
Efficiency 25 to 30 %
Speed Medium to High Speed
Application Bikes, Cars Etc