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Internal combustion engine From Wikipedia, the free encyclopedia Jump to: navigation, search Animation of two-stroke engine in operation, with a tuned pipe exhaust.

A second class of internal combustion engines use continuous combustion: gas turbines, jet engines and most rocket engines, each of which are internal combustion engines on the same principle as previously described.[1]

Common layouts of engines are: Reciprocating: Two-stroke engine Four-stroke engine (Otto cycle) Six-stroke engine Diesel engine Atkinson cycle Miller cycle Rotary: Wankel engine Continuous combustion: Gas turbine Jet engine (including turbojet, turbofan, ramjet, Rocket, etc.)

In thermodynamic terms it follows the Otto engine cycle, so may be thought of as a "four-phase" engine.

Incomplete combustion usually results from insufficient oxygen to achieve the perfect stoichiometric ratio.

The advantage of having one power stroke for every 360° of crankshaft rotation (compared to 720° in a 4-stroke motor) is balanced by the less complete intake and exhaust and the shorter effective compression and power strokes.

The combustion process typically results in the production of a great quantity of heat, as well as the production of steam and carbon dioxide and other chemicals at very high temperature; the temperature reached is determined by the chemical make up of the fuel and oxidisers (see stoichiometry), as well as by the compression and other factors.

A second class of internal combustion engines use continuous combustion: gas turbines, jet engines and most rocket engines, each of which are internal combustion engines on the same principle as previously described.[1]

A Power stroke: When the piston reaches a point just before top dead center, the spark plug ignites the fuel mixture.

PV diagram for Otto cycle On the PV-diagram, 1-2: Intake: suction stroke 2-3: Isentropic Compression stroke 3-4: Heat addition stroke 4-5: Exhaust stroke (Isentropic expansion) 5-2: Heat rejection The distance between points 1-2 is the stroke of the engine.

The most common method in spark-ignition two-strokes is to use the downward motion of the piston to pressurize fresh charge in the crankcase, which is then blown through the cylinder through ports in the cylinder walls.

Multiple crankshaft configurations do not necessarily need a cylinder head at all because they can instead have a piston at each end of the cylinder called an opposed piston design.

In a reciprocating engine, the high-pressure gases inside the cylinders drive the engine's pistons.

Gas turbines Main article: gas turbine A gas turbine is a rotary machine similar in principle to a steam turbine and it consists of three main components: a compressor, a combustion chamber, and a turbine.

Modern designs (Sarich and Paggio) use air-assisted fuel injection, which avoids this loss and provides more efficiency than comparably sized four-stroke engines.

The internal combustion engine is an engine in which the combustion of a fuel (normally a fossil fuel) occurs with an oxidizer (usually air) in a combustion chamber that is an integral part of the working fluid flow circuit.

The term internal combustion engine usually refers to an engine in which combustion is intermittent, such as the more familiar four-stroke and two-stroke piston engines, along with variants, such as the six-stroke piston engine and the Wankel rotary engine.

Internal combustion engines are primarily heat engines, and as such their theoretical efficiency can be calculated by idealized thermodynamic cycles.

Adiabatic flame temperature Air-fuel ratio Bore Component parts of internal combustion engines Crude oil engine - a two-stroke engine Deglazing (engine mechanics) Diesel engine Dieselisation Direct injection Dynamometer Electric vehicle Engine test stand - information about how to check an internal combustion engine External Combustion Engine Forced induction Fossil fuels Gasoline direct injection Gas turbine Heat pump Hybrid vehicle Indirect injection Jet engine Magnesium injection cycle Piston

Further chemicals released are benzene and 1,3-butadiene that are also hazardous air pollutants.

Gas turbines Main article: gas turbine A gas turbine is a rotary machine similar in principle to a steam turbine and it consists of three main components: a compressor, a combustion chamber, and a turbine.

Not all of the fuel is completely consumed by the combustion process; a small amount of fuel is present after combustion, and some of it reacts to form oxygenates, such as formaldehyde or acetaldehyde, or hydrocarbons not originally present in the input fuel mixture.

parts of internal combustion engines Crude oil engine - a two-stroke engine Deglazing (engine mechanics) Diesel engine Dieselisation Direct injection Dynamometer Electric vehicle Engine test stand - information about how to check an internal combustion engine External Combustion Engine Forced induction Fossil fuels Gasoline direct injection Gas turbine Heat pump Hybrid vehicle Indirect injection Jet engine Magnesium injection cycle Piston engine Petrofuel Reciprocating engine Stroke

Jet fuel (aviation fuel) Residual fuel Coal: Most methanol is made from coal.

There are also engines that run on hydrogen, methanol, ethanol, liquefied petroleum gas (LPG), biodiesel, paraffin and tractor vaporizing oil (TVO).

This force moves the component over a distance, transforming chemical energy into useful mechanical energy.

Engines with appropriate modifications can also run on hydrogen gas, wood gas, or charcoal gas, as well as from so-called producer gas made from other convenient biomass.

Advantages: • It has no valves or camshaft mechanism, hence simplifying its mechanism and construction • For one complete revolution of the crankshaft, the engine executes one cycle—the 4-stroke executes one cycle per two crankshafts revolutions.

The main derivatives of the process are carbon dioxide CO2, water and some soot — also called particulate matter (PM).

Alternatively fuel cell technology may come to deliver its promise and the use of the internal combustion engines could even be phased out.

The shaft turns three times for each rotation of the rotor around the lobe and once for each orbital revolution around the eccentric shaft.

The most common modern fuels are made up of hydrocarbons and are derived mostly from fossil fuels (petroleum).

Not all of the fuel is completely consumed by the combustion process; a small amount of fuel is present after combustion, and some of it reacts to form oxygenates, such as formaldehyde or acetaldehyde, or hydrocarbons not originally present in the input fuel mixture.

Liquid and gaseous biofuels, such as ethanol and biodiesel (a form of diesel fuel that is produced from crops that yield triglycerides such as soybean oil), can also be used.

Ozone is not emitted directly; rather, it is a secondary air pollutant, produced in the atmosphere by the reaction of NO"x" and volatile organic compounds in the presence of sunlight.

Previous split-cycle engines have had two major problems - poor breathing (volumetric efficiency) and low thermal efficiency.

Liquid hydrogen has extremely low density (14 times lower than water) and requires extensive insulation—whilst gaseous hydrogen requires heavy tankage.

ICEs are usually powered by energy-dense fuels such as gasoline or diesel, liquids derived from fossil fuels.

Bioethanol and Biomethanol (wood alcohol) and other biofuels (see Flexible-fuel vehicle).

Though the same chemical substance, ground-level ozone should not be confused with stratospheric ozone, or the ozone layer, which protects the earth from harmful ultraviolet rays.

The main limitations on fuels are that it must be easily transportable through the fuel system to the combustion chamber, and that the fuel releases sufficient energy in the form of heat upon combustion to make practical use of the engine.

Combustion All internal combustion engines depend on combustion of a chemical fuel, typically with oxygen from the air (though it is possible to inject nitrous oxide to do more of the same thing and gain a power boost).

The compressed air is then transferred through a crossover passage from the compression cylinder into the second cylinder, where combustion and exhaust occur.

Incomplete combustion also leads to the production of carbon monoxide (CO).

This battery is recharged during operation using an electricity-generating device such as an alternator or generator driven by the engine.

This force moves the component over a distance, transforming chemical energy into useful mechanical energy.

Hydrogen peroxide power was under development for German World War II submarines.

In the United States, nitrogen oxides, PM, carbon monoxide, sulphur dioxide, and ozone, are regulated as criteria air pollutants under the Clean Air Act to levels where human health and welfare are protected.

parts of internal combustion engines Crude oil engine - a two-stroke engine Deglazing (engine mechanics) Diesel engine Dieselisation Direct injection Dynamometer Electric vehicle Engine test stand - information about how to check an internal combustion engine External Combustion Engine Forced induction Fossil fuels Gasoline direct injection Gas turbine Heat pump Hybrid vehicle Indirect injection Jet engine Magnesium injection cycle Piston engine Petrofuel Reciprocating engine Stroke

Traditionally, electric motors are not referred to as "Engines"; however, combustion engines are often referred to as "motors."

Incomplete combustion also leads to the production of carbon monoxide (CO).

For comparison, the most efficient small four-stroke motors are around 43% thermal efficiency (SAE 900648); size is an advantage for efficiency due to the increase in the ratio of volume to surface area.

cylinder in which the combustion of the fuel-air mixture takes place Intake and exhaust ports: Ports that carry fresh fuel-air mixture into the combustion chamber and products of combustion away Crankshaft: A shaft that converts reciprocating motion of the piston into rotary motion Connecting rod: A rod that connects the piston to the crankshaft Spark plug: An ignition-source in the cylinder head that initiates the combustion process Operation: When the piston moves from bottom dead center (BDC)

In an internal combustion engine (ICE) the expansion of the high-temperature and high-pressure gases produced by combustion apply direct force to some component of the engine.

Gasoline Ignition Process Gasoline engine ignition systems generally rely on a combination of a lead–acid battery and an induction coil to provide a high-voltage electric spark to ignite the air-fuel mix in the engine's cylinders.

Further chemicals released are benzene and 1,3-butadiene that are also hazardous air pollutants.

A second class of internal combustion engines use continuous combustion: gas turbines, jet engines and most rocket engines, each of which are internal combustion engines on the same principle as previously described.[1]

Exhaust As their name implies, four-stroke internal combustion engines have four basic steps that repeat with every two revolutions of the engine: (1) Intake/suction stroke (2) Compression stroke (3) Power/expansion stroke and (4) Exhaust stroke 1.

Carbon fuels contain sulfur and impurities that eventually produce sulfur monoxides (SO) and sulfur dioxide (SO2) in the exhaust, which promotes acid rain.

Gasoline Ignition Process Gasoline engine ignition systems generally rely on a combination of a lead–acid battery and an induction coil to provide a high-voltage electric spark to ignite the air-fuel mix in the engine's cylinders.

Diesel engines take in air only, and shortly before peak compression, spray a small quantity of diesel fuel into the cylinder via a fuel injector that allows the fuel to instantly ignite.

Fossil fuels include diesel fuel, gasoline and petroleum gas, and the rarer use of propane.

Other chemicals such as chlorine or fluorine have been used experimentally, but have not been found practical.

Combustion All internal combustion engines depend on combustion of a chemical fuel, typically with oxygen from the air (though it is possible to inject nitrous oxide to do more of the same thing and gain a power boost).

Air and noise pollution Air pollution Internal combustion engines such as reciprocating internal combustion engines produce air pollution emissions, due to incomplete combustion of carbonaceous fuel.

Combustion All internal combustion engines depend on combustion of a chemical fuel, typically with oxygen from the air (though it is possible to inject nitrous oxide to do more of the same thing and gain a power boost).

"The Romance of Engines", 1997 SAE, ISBN 1-56091-911-6 Horst O. Hardenberg, The Middle Ages of the Internal Combustion Engine, 1999, Society of Automotive Engineers (SAE).

The combustion process typically results in the production of a great quantity of heat, as well as the production of steam and carbon dioxide and other chemicals at very high temperature; the temperature reached is determined by the chemical make up of the fuel and oxidisers (see stoichiometry), as well as by the compression and other factors.

Recently, experiments have been made with using powdered solid fuels, such as the magnesium injection cycle.

The inlet valve opens as a result of the cam lobe pressing down on the valve stem, and the vaporized fuel mixture enters the combustion chamber.

Liquid and gaseous biofuels, such as ethanol and biodiesel (a form of diesel fuel that is produced from crops that yield triglycerides such as soybean oil), can also be used.

Two-stroke engines are widely used in snowmobiles, lawnmowers, string trimmers, chain saws, jet skis, mopeds, outboard motors, and many motorcycles.

Liquid and gaseous biofuels, such as ethanol and biodiesel (a form of diesel fuel that is produced from crops that yield triglycerides such as soybean oil), can also be used.

The combustion process typically results in the production of a great quantity of heat, as well as the production of steam and carbon dioxide and other chemicals at very high temperature; the temperature reached is determined by the chemical make up of the fuel and oxidisers (see stoichiometry), as well as by the compression and other factors.

The compressed air is then transferred through a crossover passage from the compression cylinder into the second cylinder, where combustion and exhaust occur.

Biogas Hydrogen (mainly spacecraft rocket engines) Even fluidized metal powders and explosives have seen some use.

There are, however, some additional products of the combustion process that include nitrogen oxides and sulfur and some uncombusted hydrocarbons, depending on the operating conditions and the fuel-air ratio.

Hydrogen peroxide power was under development for German World War II submarines.

The efficiency of a theoretical cycle cannot exceed that of the Carnot cycle, whose efficiency is determined by the difference between the lower and upper operating temperatures of the engine.

Two-stroke engines are widely used in snowmobiles, lawnmowers, string trimmers, chain saws, jet skis, mopeds, outboard motors, and many motorcycles.

Other chemicals such as chlorine or fluorine have been used experimentally, but have not been found practical.

Aircraft engines can also adopt a radial configuration, which allows more effective cooling.

The main derivatives of the process are carbon dioxide CO2, water and some soot — also called particulate matter (PM).

The effects of inhaling particulate matter have been studied in humans and animals and include asthma, lung cancer, cardiovascular issues, and premature death.

These attempts at imitating the principle of a steam engine were very inefficient.

There are also engines that run on hydrogen, methanol, ethanol, liquefied petroleum gas (LPG), biodiesel, paraffin and tractor vaporizing oil (TVO).

Working fluids can be air, hot water, pressurized water or even liquid sodium, heated in some kind of boiler.

Except for the fuel delivery components, most internal combustion engines that are designed for gasoline use can run on natural gas or liquefied petroleum gases without major modifications.

The inlet valve opens as a result of the cam lobe pressing down on the valve stem, and the vaporized fuel mixture enters the combustion chamber.

Before the invention of reliable electrical methods, hot tube and flame methods were used.

The Beare Head and "piston charger" engines operate as opposed-piston engines, two pistons in a single cylinder, firing every two revolutions rather more like a regular four-stroke.

The effects of inhaling particulate matter have been studied in humans and animals and include asthma, lung cancer, cardiovascular issues, and premature death.

Engines with appropriate modifications can also run on hydrogen gas, wood gas, or charcoal gas, as well as from so-called producer gas made from other convenient biomass.

In the United States, nitrogen oxides, PM, carbon monoxide, sulphur dioxide, and ozone, are regulated as criteria air pollutants under the Clean Air Act to levels where human health and welfare are protected.

The effects of inhaling particulate matter have been studied in humans and animals and include asthma, lung cancer, cardiovascular issues, and premature death.

Accessed April 2011 ^ Gasifier Aids Motor Starting Under Arctic Conditions.

The effects of inhaling particulate matter have been studied in humans and animals and include asthma, lung cancer, cardiovascular issues, and premature death.