Super Charging

Super Charging

The power output of an engine depends up on the amount of air indicated per unit time, the degree of utilization of this air and the thermal efficiency of the engine. The amount of air inducted per unit time can be increased by increasing the engine speed pr by increasing the engine speed or by increasing the density of air intake. The method increasing the inlet air density, called supercharging, is usually employed to increase the power output of the engine. This is done by supplying air to a pressure higher than the pressure at which the engine naturally aspirates air from the atmosphere by using a pressure boosting device called a super charger.

OBJECTS OF SUPERCHARGING

The increase in the amount of air inducted per unit time by supercharging is obtained mainly to burn a greater amount of fuel in a given engine and thus increase its power output. The objects of supercharging include one or more of the following.

1. To increase the power output for a given weight and bulk of the engine. This is important for aircraft, marine and automotive engines where weight and space are important.

2. To compensate for the loss of power due to altitude. This mainly relates to aircraft engines which lose power at an approximate rate of one percent 100 meters altitude. This is also relevant for others engines which are used at high altitudes.

A supercharger is an air compressor used for forced induction of an internal combustion engine. The greater mass flow-rate provides more oxygen to support combustion than would be available in a naturally-aspirated engine, which allows more fuel to be provided and more work to be done per cycle, increasing the power output of the engine.

A supercharger can be powered mechanically by a belt, gear, shaft, or chain connected to the engine's crankshaft. It can also be powered by an exhaust gas turbine. A turbine-driven supercharger is known as a turbosupercharger or turbocharger. The term supercharging technically refers to any pump that forces air into an engine—but in common usage, it refers to pumps that are driven directly by the engine as opposed to turbochargers that are driven by the pressure of the exhaust gases.

Thermal Barrier Coatings

Thermal Barrier Coatings

Definition

Thermal barrier coatings (TBC) are layer systems deposited on thermally highly loaded metallic components, as for instance in gas turbines. The accompanying figure shows a stator blade of a stationary gas turbine, furnished with a plasma sprayed thermal barrier coating of YSZ (Siemens Power Generation). The cooling of the components causes a pronounced reduction of the metal temperature, which leads to a prolongation of the mechanical component's lifetime. Alternatively, the use of thermal barrier coatings allows to raise the process temperature, obtaining thus an increased efficiency.

Heat engines are based on considering various factors such as durability, performance and efficiency with the objective of minimizing the life cycle cost. For example, the turbine inlet temperature of a gas turbine having advanced air cooling and improved component materials is about 1500oC. Metallic coatings were introduced to sustain these high temperatures. The trend for the most efficient gas turbines is to exploit more recent advances in material and cooling technology by going to engine operating cycles which employ a large fraction of the maximum turbine inlet temperature capability for the entire operating cycle. Thermal Barrier Coatings (TBC) performs the important function of insulating components such as gas turbine and aero engine parts operating at elevated temperatures. Thermal barrier coatings (TBC) are layer systems deposited on thermally highly loaded metallic components, as for instance in gas turbines. TBC's are characterized by their low thermal conductivity, the coating bearing a large temperature gradient when exposed to heat flow. The most commonly used TBC material is Yttrium Stabilized Zirconia (YSZ), which exhibits resistance to thermal shock and thermal fatigue up to 1150oC. YSZ is generally deposited by plasma spraying and electron beam physical vapour deposition (EBPVD) processes. It can also be deposited by HVOF spraying for applications such as blade tip wear prevention, where the wear resistant properties of this material can also be used. The use of the TBC raises the process temperature and thus increases the efficiency.

Structure Of Thermal Barrier Coatings

Thermal Barrier Coating consists of two layers (duplex structure). The first layer, a metallic one, is called bond coat, whose function is to protect the basic material against oxidation and corrosion. The second layer is an oxide ceramic layer, which is glued or attached by a metallic bond coat to the super alloy. The oxide that is commonly used is Zirconia oxide (ZrO2) and Yttrium oxide (Y2O3). The metallic bond coat is an oxidation/hot corrosion resistant layer. The bond coat is empherically represented as MCrAlY alloy where

M - Metals like Ni, Co or Fe.
Y - Reactive metals like Yttrium.
CrAl - base metal.

Coatings are well established as an important underpinning technology for the manufacture of aeroengine and industrial turbines. Higher turbine combustion temperatures are desirable for increased engine efficiency and environmental reasons (reduction in pollutant emissions, particularly NOx), but place severe demands on the physical and chemical properties of the basic materials of fabrication.

In this context, MCrAlY coatings (where M = Co, Ni or Co/Ni) are widely applied to first and second stage turbine blades and nozzle guide vanes, where they may be used as corrosion resistant overlays or as bond-coats for use with thermal barrier coatings. In the first and second stage of a gas turbine, metal temperatures may exceed 850°C, and two predominant corrosion mechanisms have been identified:

Accelerated high temperature oxidation (>950°C) where reactions between the coating and oxidants in the gaseous phase produce oxides on the coating surface as well as internal penetration of oxides/sulphides within the coating, depending on the level of gas phase contaminants

Type I hot corrosion (850 - 950°C) where corrosion occurs through reaction with salts deposited from the vapour phase (from impurities in the fuel). Molten sulphates flux the oxide scales, and non-protective scales, extensive internal suplhidation and a depletion zone of scale-forming elements characterize the microstructure.

Thermal barrier coatings are highly advanced material systems applied to metallic surfaces, such as gas turbine or aero-engine parts, operating at elevated temperatures. These coatings serve to insulate metallic components from large and prolonged heat loads by utilizing thermally insulating materials which can sustain an appreciable temperature difference between the load bearing alloys and the coating surface.In doing so, these coatings can allow for higher operating temperatures while limiting the thermal exposure of structural components, extending part life by reducing oxidation and thermal fatigue. In fact, in conjunction with active film cooling, TBCs permit working fluid temperatures higher than the melting point of the metal airfoil in some turbine applications.

Background

Thermal Barrier Caotings are typically ceramic composites based on zirconia, alumina, and titanium.. The high hardnes, wear resisrance and good chemical stability of TBCs make them very desirable in cutting tool applications. TBCs provide good resistance against the corrosive, high temperature environment of aircraft engines as well. Wear resistance can increase between 200 to 500% with the addition of a TBC to a tool. Chemical vapor deposition (CVD), plasma vapor deposition (PVD), and electron beam physical vapor deposition (EBPVD) are the primary deposition methods for these coatings.


The adhesion quality of the TBC to the substrate is considered to be one of the limiting factors for use of these materials. Previous studies using pull-off methods to determine the adhesion do not sufficiently describe the mechanism of failure. In addition, a large difference in the thermal expansion coefficient between the interface and the substrate is a potential cause for spalling of the coating. This research will attempt to characterize the mechanical properties of the interface, in particular the interface fracture resistance and progressive debonding.

Cutting Tool Applications

The addition of a TBC is credited for increasing cutting speeds of tools and for providing deeper cuts. In particular, TBCs provide excellent wear resistance which is necessary in the harsh tool environment. Wear mechanisms of cutting tools, include crater, attrition, flank, and abrasive wear. It has been shown that TBCs can limit the crater and attrition wear processes.

Multi-layer coatings increase performance as the combination exhibits the best qualities of each coating. These coatings are also known to produce finer grain sizes and minimize chopping. The research will demonstrate the reliability of the combinations already in service.

The Hy-Wire Car

The Hy-Wire Car
Definition

Cars are immensely complicated machines, but when you get down to it, they do an incredibly simple job. Most of the complex stuff in a car is dedicated to turning wheels, which grip the road to pull the car body and passengers along. The steering system tilts the wheels side to side to turn the car, and brake and acceleration systems control the speed of the wheels.

Given that the overall function of a car is so basic (it just needs to provide rotary motion to wheels), it seems a little strange that almost all cars have the same collection of complex devices crammed under the hood and the same general mass of mechanical and hydraulic linkages running throughout. Why do cars necessarily need a steering column, brake and acceleration pedals, a combustion engine, a catalytic converter and the rest of it?

According to many leading automotive engineers, they don't; and more to the point, in the near future, they won't. Most likely, a lot of us will be driving radically different cars within 20 years. And the difference won't just be under the hood -- owning and driving cars will change significantly, too.

In this article, we'll look at one interesting vision of the future, General Motor's remarkable concept car, the Hy-wire. GM may never actually sell the Hy-wire to the public, but it is certainly a good illustration of various ways cars might evolve in the near future.

Hy-Wire Basics

Two basic elements largely dictate car design today: the internal combustion engine and mechanical and hydraulic linkages. If you've ever looked under the hood of a car, you know an internal combustion engine requires a lot of additional equipment to function correctly. No matter what else they do with a car, designers always have to make room for this equipment.

The same goes for mechanical and hydraulic linkages. The basic idea of this system is that the driver maneuvers the various actuators in the car (the wheels, brakes, etc.) more or less directly, by manipulating driving controls connected to those actuators by shafts, gears and hydraulics. In a rack-and-pinion steering system, for example, turning the steering wheel rotates a shaft connected to a pinion gear, which moves a rack gear connected to the car's front wheels. In addition to restricting how the car is built, the linkage concept also dictates how we drive: The steering wheel, pedal and gear-shift system were all designed around the linkage idea.

Space Shuttle

Previously, all ventures in to space were achieved with giant rockets which, after a certain amount of time , were directed back in to the earth’s atmosphere to be reduced to a cinder by the enormous heat of re entry –after the crew and their capsule had been ejected virtually all of that tremendously expensive equipment was destroyed after only one use.

Following are the main supporting systems of a space shuttle.

1. Propulsion system
2. External fuel tank
3. Space shuttle orbiter

gate valve

A gate valve is a valve that opens by lifting a round or rectangular gate out of the path of the fluid. The distinct feature of a gate valve is the sealing surfaces between the gate and seats are planar. The gate faces can form a wedge shape or they can be parallel. Gate valves are sometimes used for regulating flow, but many are not suited for that purpose, having been designed to be fully opened or closed. When fully open, the typical gate valve has no obstruction in the flow path, resulting in very low friction loss.
Bonnets provide leakproof closure for the valve body. Gate valves may have a screw-in, union, or bolted bonnet. Screw-in bonnet is the simplest, offering a durable, pressure-tight seal. Union bonnet is suitable for applications requiring frequent inspection and cleaning. It also gives the body added strength. Bolted bonnet is used for larger valves and higher pressure applications.
Another type of bonnet construction in a gate valve is pressure seal bonnet. This construction is adopted for valves for high pressure service, typically in excess of 2250 psi. The unique feature about the pressure seal bonnet is that the body - bonnet joints seals improves as the internal pressure in the valve increases, compared to other constructions where the increase in internal pressure tends to create leaks in the body-bonnet joint.

SMART MATERIAL

In the field of massive and complex manufacturing we are now in need of materials, with properties, that can be manipulated according to our needs. Smart materials are one among those unique materials, which can change its shape or size simply by adding a little bit of heat, or can change from a liquid to a solid almost instantly when near a magnet. These materials include piezoelectric materials, magneto-rheostatic materials, electro-rheostatic materials, and shape memory alloys. Shape memory alloys are metals, which exhibit two very unique properties, pseudo-elasticity (an almost rubber-like flexibility, under-loading), and the shape memory effect (ability to be severely deformed and then return to its original shape simply by heating). The two unique properties described above are made possible through a solid state phase change that is a molecular rearrangement, in which the molecules remain closely packed so that the substance remains a solid. The two phases, which occur in shape memory alloys, are Martensite, and Austenite.

NANOTECHNOLOGY A DEEP INSIGHT

Nanotechnology, development and production of artefacts in which a dimension of less than 100 nanometres (nm) is critical to functioning (1 nm = 10-9 m/40 billionths of an inch). Nanotechnology is a hybrid science combining engineering and chemistry. Atoms and molecules stick together because they have complementary shapes that lock tog- ether, or charges that attract. As millions of these atoms are pieced together by nanomachines, a specific product will begin to take shape. The goal of nanotechnology is to manipulate atoms individually and place them in a pattern to produce a desired structure. Nanotechnology is likely to change the way almost everything, including medicine, computers and cars, are designed and constructed. Nanotechnology holds out the promise of materials of precisely specified composition and properties, which could yield structures of unprecedented strength and computers of extraordinary compactness and power. Nanotechnology may lead to revolutionary methods of atom-by-atom manufacturing and to surgery on the cellular scale. Scientists have made some progress at building devices, including computer components, at nanoscales. Nanotechnology is anywhere from five to 15 years in the future.

Airbag

For years, the trusty seatbelts provided the sole form of passive restraints in our car. There were debates about their safety, especially related to children, but over time, much of the country adopted mandatory seat-belt laws. Statistics have show that seat-belts have saved thousands of lives that might have been lost in collisions.Airbags have been under development for many years. The first commercial airbags appeared in automobiles in the 1980s.They are a proven safety device that save a growing number of lives, and prevent a large number of head and chest injuries. They are reducing driver deaths by 14 percent and passenger bags reduce deaths by about 11 percent.
People who use seat-belts think they do not need airbags. But they do. Airbags and lap/shoulder belts work together as a system, and one without the other isn't as effective. Deaths are 12 percent lower among drivers with belts and 9 percent lower among belted passengers.
Since model year, all new cars have been required to have airbags on both driver and passenger sides. Light trucks came under the rule in 1999.Newer than steering-wheel-mounted or dashboard-mounted bags are seat-mounted door-mounted and window airbags. Airbags are subject of serious government and industry researches and tests.
Airbags can cause some unintended adverse effects. Nearly all of these are minor injuries like bruises and abrasions that are more than offset by the lives airbags are saving.You can eliminate this risk, and position is what counts. Serious inflation injuries occur primarily because of peoples position when airbags first begin inflating.
Stopping an objects momentum requires force acting over a period of time. When a car crashes the force required to stop an object is very great because the car's momentum has changed instantly while the passengers has not. The goal of any supplement restraint system is to help stop the passengers while doing as little damage to him or her as possible.
What an airbag want to do is to slow down the passenger's speed to zero with little or no damage .The constraints that it has to work are huge .The airbag has the space between the passenger and the steering wheel or dashboard and a fraction of a second to work with. Even that tiny amount of space and time is valuable

Cam less Engines

The cam has been an integral part of the IC engine from its invention. The cam controls the "breathing channels" of the IC engines, that is, the valves through which the fuel air mixture (in SI engines) or air (in CI engines) is supplied and exhaust driven out.
Besieged by demands for better fuel economy, more power, and less pollution, motor engineers around the world are pursuing a radical "camless" design that promises to deliver the internal-combustion engine's biggest efficiency improvement in years. The aim of all this effort is liberation from a constraint that has handcuffed performance since the birth of the internal-combustion engine more than a century ago. Camless engine technology is soon to be a reality for commercial vehicles. In the camless valvetrain, the valve motion is controlled directly by a valve actuator - there's no camshaft or connecting mechanisms. Precise electronic circuit controls the operation of the mechanism, thus bringing in more flexibility and accuracy in opening and closing the valves. The seminar looks at the working of the electronically controlled camless engine, its general features and benefits over conventional engine.

The engines powering today's vehicles, whether they burn gasoline or diesel fuel, rely on a system of valves to admit fuel and air to the cylinders and to let exhaust gases escape after combustion. Rotating steel camshafts with precision-machined egg-shaped lobes, or cams, are the hard-tooled "brains" of the system. They push open the valves at the proper time and guide their closure, typically through an arrangement of pushrods, rocker arms, and other hardware. Stiff springs return the valves to their closed position

Ball Piston machines

From the day machines with reciprocating piston has come into existence efforts have been undertaken to improve the efficiency of the machines .The main drawbacks of reciprocating machines are the considerably large number of moving parts due to the presence of valves , greater inertial loads which reduces dynamic balance and leakage and friction due to the presence of piston rings . The invention urges has reached on Rotary machines .

One main advantage to be gained with a rotary machine is reduction of inertial loads and better dynamic balance. The Wankel rotary engine has been the most successful example to date , but sealing problems contributed to its decline . There , came the ideas of ball piston machines . In the compressor and pump arena, reduction of reciprocating mass in positive displacement machines has always been an objective, and has been achieved most effectively by lobe, gear, sliding vane, liquid ring, and screw compressors and pumps , but at the cost of hardware complexity or higher losses. Lobe, gear, and screw machines have relatively complex rotating element shapes and friction losses. Sliding vane machines have sealing and friction issues . Liquid ring compressors have fluid turbulence losses.

The new design concept of the Ball Piston Engine uses a different approach that has many advantages, including low part count and simplicity of design , very low friction , low heat loss, high power to weight ratio , perfect dynamic balance , and cycle thermodynamic tailoring capability

DIAMOND CUTTING TOOL AND COATINGS

Diamond is the hardest material known to man kind. When used on tools, diamond grinds away material on micro (Nano) level. Diamond is the hardest substance known and is given a value of 10 in the Mohs hardness scale, devised by the German mineralogist Friedrich Mohs to indicate relative hardness of substances on a rating scale from 1 to 10. Its hardness varies in every diamond with the crystallographic direction. Moreover, hardness on the same face or surface varies with the direction of the cut.

Diamond crystallizes in different forms. Eight and twelve sided crystal forms are most commonly found. Cubical, rounded, and paired crystals are also common. Crystalline diamonds always separate cleanly along planes parallel to the faces. The specific gravity for pure diamond crystals is almost always 3.52. Other properties of the diamond are frequently useful in differentiating between true diamonds and imitations: Because diamonds are excellent conductors of heat, they are cold to the touch; Most diamonds are not good electrical conductors and become charged with positive electricity when rubbed; Diamond is resistant to attack by acids or bases; Transparent diamond crystals heated in oxygen burn at about 1470° F, forming carbon dioxide

Pyrometers

The Technique of measuring high temperature is known as pyrometry and the instrument employed is called pyrometer. Pyrometer is specialized type of thermometer used to measure high temperatures in the production and heat treatment of metal and alloys. Ordinary temperatures can be measured by ordinary thermometer, instead pyrometer is employed for measuring higher temperature.
Any metallic surface when heated emits radiation of different wavelengths which are not visible at low temperatures but at about 5400C radiations are in shorter wavelength and are visible to eye and from colour judgement is made as to probable temperature, the colour scale is roughly as follows.

Dark red - 5400C
Red - 7000C
Bright red - 3500C
Orange - 9000C
Yellow - 10100C
White - 12050C and above

The Technique of measuring high temperature is known as pyrometry and the instrument employed is called pyrometer. Pyrometer is specialized type of thermometer used to measure high temperatures in the production and heat treatment of metal and alloys. Ordinary temperatures can be measured by ordinary thermometer, instead pyrometer is employed for measuring higher temperature.
Any metallic surface when heated emits radiation of different wavelengths which are not visible at low temperatures but at about 5400C radiations are in shorter wavelength and are visible to eye and from colour judgement is made as to probable temperature, the colour scale is roughly as follows.

Dark red - 5400C
Red - 7000C
Bright red - 3500C
Orange - 9000C
Yellow - 10100C
White - 12050C and above

When a substance receives heat, change in pressure, electric resistance, radiation, thermoelectric e.m.f and or colour may takeplace. Any of these change can be used for measurement of temperature. Inorder to exercise provision control over the heat treatment and melting operation in the industry temperaturemeasuring device known as pyrometers are used. Also accurate measurement of temperature of Furnaces, molten metals and other heated materials

Smart combustors

This seminar will review the state of the art of active control of gas turbine combustors processes. The seminar will first discuss recently developed approaches for active control of detrimental combustion instabilities by use of 'fast' injectors that modulate the fuel injection rate at the frequency of the instability and appropriate phase and gain. Next, the paper discusses two additional approaches for damping of combustion instabilities; i.e., active modification of the combustion process characteristics and open loop modulation of the fuel injection rate at frequencies that differ from the instability frequency. The second part of the seminar will discuss active control of lean blowout in combustors that burn fuel in a lean premixed mode of combustion to reduce NOx emissions. This discussion will describe recent developments of optical and acoustic sensing techniques that employ sophisticated data analysis approaches to detect the presence of lean blowout precursors in the measured data. It will be shown that this approach can be used to determine in advance the onset of lean blowout and that the problem can be prevented by active control of the relative amounts of fuel supplied to the main, premixed, combustion region and a premixed pilot flame. The will close with a discussion of research needs, with emphasis on the integration of utilized active control and health monitoring and prognostication systems into a single combustor control system

Green Engine

This seminar representing the Green engine effect. That is for increasing the efficiency of the engine and avoiding excessive pollution a new method adopting, a ceramic coating [non-metallic solid coating]is done on the parts like piston and crown of the engine used in automobiles

Factors affecting the efficiency

Incomplete combustion
Carbon deposition
Thermal shocking
Pollution control

For avoiding these factors we adopt the method of ceramic coating on the engine Features of ceramic coating We conduct various process in this coating

1. Physical vapour deposition
2. Chemical vapour deposition
3. Ion plating
4. Spattering
5. HAIPAP

Advantages

1. This prevents he deposition of carbon over the cylinder head and piston

2. It acts as a thermal barrier which reduces the amount of heat leakage

3. It help complete combustion of fuels

4. It avoids thermal shocking

5. All the factors above contribute increases the efficiency up to 9% and reduction in pollution in a wide rate

Limitations

1. Additional reactions takes place due to coating.
2. High expense for coating

E85

E85 is an alcohol fuel mixture of 85% ethanol and 15% gasoline, by volume. ethanol derived from crops (bioethanol) is a biofuel.
E85 as a fuel is widely used in Sweden and is becoming increasingly common in the United States, mainly in the Midwest where corn is a major crop and is the primary source material for ethanol fuel production.
E85 is usually used in engines modified to accept higher concentrations of ethanol. Such flexible-fuel engines are designed to run on any mixture of gasoline or ethanol with up to 85% ethanol by volume. The primary differences from non-FFVs is the elimination of bare magnesium, aluminum, and rubber parts in the fuel system, the use of fuel pumps capable of operating with electrically-conductive (ethanol) instead of non-conducting dielectric (gasoline) fuel, specially-coated wear-resistant engine parts, fuel injection control systems having a wider range of pulse widths (for injecting approximately 30% more fuel), the selection of stainless steel fuel lines (sometimes lined with plastic), the selection of stainless steel fuel tanks in place of terne fuel tanks, and, in some cases, the use of acid-neutralizing motor oil. For vehicles with fuel-tank mounted fuel pumps, additional differences to prevent arcing, as well as flame arrestors positioned in the tank's fill pipe, are also sometimes used.

CVCC

CVCC is a trademark by the Honda Motor Company for a device used to reduce automotive emissions called Compound Vortex Controlled Combustion. This technology allowed Honda's cars to meet the 1970s US Emission requirements without a catalytic converter, and first appeared on the 1975 ED1 engine. It is a form of stratified charge engine.
Honda CVCC engines have normal inlet and exhaust valves, plus a small auxiliary inlet valve which provides a relatively rich air / fuel mixture to a volume near the spark plug. The remaining air / fuel charge, drawn into the cylinder through the main inlet valve is leaner than normal. The volume near the spark plug is contained by a small perforated metal plate. Upon ignition flame fronts emerge from the perforations and ignite the remainder of the air / fuel charge. The remaining engine cycle is as per a standard four stroke engine.
This combination of a rich mixture near the spark plug, and a lean mixture in the cylinder allowed stable running, yet complete combustion of fuel, thus reducing CO (carbon monoxide) and hydrocarbon emissions.

Diesel Particulate Filter

A Diesel Particulate Filter, sometimes called a DPF, is device designed to remove Diesel Particulate Matter or soot from the exhaust gas of a Diesel engine, most of which are rated at 85% efficiency, but often attaining efficiencies of over 90%. A Diesel-powered vehicle with a filter installed will emit no visible smoke from its exhaust pipe.
In addition to collecting the particulate, a method must be designed to get rid of it. Some filters are single use (disposable), while others are designed to burn off the accumulated particulate, either through the use of a catalyst (passive), or through an active technology, such as a fuel burner which heats the filter to soot combustion temperatures, or through engine modifications (the engine is set to run a certain specific way when the filter load reachs a pre-determined level, either to heat the exhaust gasses, or to produce high amounts of No2, which will oxidize the particualte at relatively low temperatures). This procedure is known as 'filter regeneration.' Fuel sulfur interferes many 'Regeneration' strategies, and all jurisdictions that are interested in reduction of particulate emissions, are also passing regulations governing fuel sulfur levels.

Butterfly valve

A Butterfly valve is a type of flow control device, used to make a fluid start or stop flowing through a section of pipe. The valve is similar in operation to a ball valve. A flat circular plate is positioned in the center of the pipe. The plate has a rod through it connected to a handle on the outside of the valve. Rotating the handle turns the plate either parallel or perpendicular to the flow of water, shutting off the flow. It is a very robust and reliable design. However, unlike the ball valve, the plate does not rotate out of the flow of water, so that a pressure drop is induced in the flow.
There are three types of butterfly valve:
1.Resilient butterfly valve which has a flexible rubber seat. Working pressure up to 1.6 Mpa.
2.High performance butterfly valve which is usually double eccentric in design . Working pressure up to 5.0 Mpa.
3.Tricentric butterfly valve which is usually with metal seated design. Working pressure up to 10.0 Mpa.
Butterfly valves are also commonly utilised in conjunction with carburetors to control the flow of air through the intake manifold and hence the flow of fuel and air into an internal combustion engine. The butterfly valve in this circumstance called a throttle as it is 'throttling' the engines aspiration. It is controlled via a cable or electronics by the furthest right pedal in the drivers footwell (although adaptions for hand control do exist). This is why the accelerator pedal in some countries is called a throttle pedal.

Globe valves

Globe valves are named for their spherical body shape. The two halves of the valve body are separated by a baffle with a disc in the center. Globe valves operate by screw action of the handwheel. They are used for applications requiring throttling and frequent operation. Since the baffle restricts flow, they're not recommended where full, unobstructed flow is required.

A bonnet provides leakproof closure for the valve body. Globe valves may have a screw-in, union, or bolted bonnet. Screw-in bonnet is the simplest bonnet, offering a durable, pressure-tight seal. Union bonnet is suitable for applications requiring frequent inspection or cleaning. It also gives the body added strength. Bolted bonnet is used for larger or higher pressure applications.
Many globe valves have a class rating that corresponds to the pressure specifications of ANSI 16.34. Other different types of valve usually are called globe style valves because of the shape of the body or the way of closure of the disk. As an example typical swing check valves could be called globe type.

stratified charge engine

The stratified charge engine is a type of internal-combustion engine, similar in some ways to the Diesel cycle, but running on normal gasoline. The name refers to the layering of fuel/air mixture, the charge inside the cylinder.

In a traditional Otto cycle engine the fuel and air are mixed outside the cylinder and are drawn into it during the intake stroke. The air/fuel ratio is kept very close to stoichiometric, which is defined as the exact amount of air necessary for a complete combustion of the fuel. This mixture is easily ignited and burns smoothly.

The problem with this design is that after the combustion process is complete, the resulting exhaust stream contains a considerable amount of free single atoms of oxygen and nitrogen, the result of the heat of combustion splitting the O₂ and N₂ molecules in the air. These will readily react with each other to create NO_x, a pollutant. A catalytic converter in the exhaust system re-combines the NO_x back into O₂ and N₂ in modern vehicles.

A Diesel engine, on the other hand, injects the fuel into the cylinder directly. This has the advantage of avoiding premature spontaneous combustion—a problem known as detonation or ping that plagues Otto cycle engines—and allows the Diesel to run at much higher compression ratios. This leads to a more fuel-efficient engine. That is why they are commonly found in applications where they are being run for long periods of time, such as in trucks.