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Contents.Terminology The word engine derives from, from the ingenium–the root of the word. Pre-industrial weapons of war, such as, and, were called, and knowledge of how to construct them was often treated as a military secret. The word gin, as in, is short for engine.
Most mechanical devices invented during the were described as engines—the steam engine being a notable example. However, the original steam engines, such as those by, were not mechanical engines but pumps. In this manner, a in its original form was merely a water pump, with the engine being transported to the fire by horses.In modern usage, the term engine typically describes devices, like steam engines and internal combustion engines, that burn or otherwise consume fuel to perform by exerting a or linear (usually in the form of ). Devices converting heat energy into motion are commonly referred to simply as engines. Examples of engines which exert a torque include the familiar automobile gasoline and diesel engines, as well as. Examples of engines which produce thrust include and.When the internal combustion engine was invented, the term motor was initially used to distinguish it from the steam engine—which was in wide use at the time, powering locomotives and other vehicles such as.
The term derives from the Latin verb which means to set in motion, or maintain motion. Thus a motor is a device that imparts motion.Motor and engine are interchangeable in standard English. In some engineering jargons, the two words have different meanings, in which is a device that or otherwise consumes fuel, changing its chemical composition, and a motor is a device driven by, or pressure, which does not change the chemical composition of its energy source. However, uses the term, even though they consume fuel.A heat engine may also serve as a —a component that transforms the flow or changes in pressure of a into.
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An powered by an internal combustion engine may make use of various motors and pumps, but ultimately all such devices derive their power from the engine. Another way of looking at it is that a motor receives power from an external source, and then converts it into mechanical energy, while an engine creates power from pressure (derived directly from the explosive force of combustion or other reaction, or secondarily from the action of some such force on other substances such as air, water, or steam). History Antiquity , such as the and (examples of the ), are. More complex engines using, and even steam power date back to antiquity.
Human power was focused by the use of simple engines, such as the, or, and with, and arrangements; this power was transmitted usually with the forces and the speed. These were used in and aboard in, as well as in, and in. The writers of those times, including, and, treat these engines as commonplace, so their invention may be more ancient. By the 1st century AD, and were used in, driving machines similar to those powered by humans in earlier times.According to, a water powered mill was built in Kaberia of the during the 1st century BC.
Use of in mills spread throughout the over the next few centuries. Some were quite complex, with, and to maintain and channel the water, along with systems of, or toothed-wheels made of wood and metal to regulate the speed of rotation. More sophisticated small devices, such as the used complex trains of gears and dials to act as calendars or predict astronomical events. In a poem by in the 4th century AD, he mentions a stone-cutting saw powered by water. Is credited with many such and powered machines in the 1st century AD, including the and the, often these machines were associated with worship, such as animated altars and automated temple doors.Medieval Medieval Muslim engineers employed in mills and water-raising machines, and used as a source of water power to provide additional power to watermills and water-raising machines. In the, such advances made it possible to many industrial tasks previously carried out by.In 1206, employed a - system for two of his water-raising machines.
A rudimentary device was described by in 1551 and by in 1629.In the 13th century, the solid was invented in China. Driven by gunpowder, this simplest form of internal combustion engine was unable to deliver sustained power, but was useful for propelling weaponry at high speeds towards enemies in battle and for. After invention, this innovation spread throughout Europe.Industrial Revolution. Boulton & Watt engine of 1788The was the first type of steam engine to make use of steam at a pressure just above to drive the piston helped by a partial vacuum.
Improving on the design of the 1712, the Watt steam engine, developed sporadically from 1763 to 1775, was a great step in the development of the steam engine. Offering a dramatic increase in, 's design became synonymous with steam engines, due in no small part to his business partner,.
It enabled rapid development of efficient semi-automated factories on a previously unimaginable scale in places where waterpower was not available. Later development led to and great expansion of.As for internal combustion piston engines, these were tested in France in 1807 by and independently, by the. They were theoretically advanced by in 1824.
In 1853–57 and invented and patented an engine using the free-piston principle that was possibly the first 4-cycle engine.The invention of an which was later commercially successful was made during 1860 by.In 1877 the was capable of giving a far higher than steam engines and worked much better for many transportation applications such as cars and aircraft.Automobiles The first commercially successful automobile, created by, added to the interest in light and powerful engines. The lightweight petrol internal combustion engine, operating on a four-stroke Otto cycle, has been the most successful for light automobiles, while the more efficient is used for trucks and buses.
However, in recent years, turbo Diesel engines have become increasingly popular, especially outside of the United States, even for quite small cars.Horizontally opposed pistons In 1896, Karl Benz was granted a patent for his design of the first engine with horizontally opposed pistons. His design created an engine in which the corresponding pistons move in horizontal cylinders and reach top dead center simultaneously, thus automatically balancing each other with respect to their individual momentum. Engines of this design are often referred to as flat engines because of their shape and lower profile. They were used in the, the, some Porsche and Subaru cars, many and, and propeller.Advancement Continuance of the use of the internal combustion engine for automobiles is partly due to the improvement of engine control systems (onboard computers providing engine management processes, and electronically controlled fuel injection). Forced air induction by turbocharging and supercharging have increased power outputs and engine efficiencies. Similar changes have been applied to smaller diesel engines giving them almost the same power characteristics as petrol engines.
This is especially evident with the popularity of smaller diesel engine propelled cars in Europe. Larger diesel engines are still often used in trucks and heavy machinery, although they require special machining not available in most factories. Diesel engines produce lower and CO2 emissions, but greater and pollution, than gasoline engines. Diesel engines are also 40% more fuel efficient than comparable gasoline engines.
Increasing power In the first half of the 20th century, a trend of increasing engine power occurred, particularly in the U.S models. Design changes incorporated all known methods of increasing engine capacity, including increasing the pressure in the cylinders to improve efficiency, increasing the size of the engine, and increasing the rate at which the engine produces work.
The higher forces and pressures created by these changes created engine vibration and size problems that led to stiffer, more compact engines with V and opposed cylinder layouts replacing longer straight-line arrangements.Combustion efficiency The design principles favoured in Europe, because of economic and other restraints such as smaller and twistier roads, leant toward smaller cars and corresponding to the design principles that concentrated on increasing the combustion efficiency of smaller engines. This produced more economical engines with earlier four-cylinder designs rated at 40 horsepower (30 kW) and six-cylinder designs rated as low as 80 horsepower (60 kW), compared with the large volume V-8 American engines with power ratings in the range from 250 to 350 hp, some even over 400 hp (190 to 260 kW). Engine configuration Earlier automobile engine development produced a much larger range of engines than is in common use today. Engines have ranged from 1- to 16-cylinder designs with corresponding differences in overall size, weight, and cylinder. Four cylinders and power ratings from 19 to 120 hp (14 to 90 kW) were followed in a majority of the models. Several three-cylinder, two-stroke-cycle models were built while most engines had straight or in-line cylinders. There were several V-type models and horizontally opposed two- and four-cylinder makes too.
Overhead were frequently employed. The smaller engines were commonly air-cooled and located at the rear of the vehicle; compression ratios were relatively low. The 1970s and 1980s saw an increased interest in improved, which caused a return to smaller V-6 and four-cylinder layouts, with as many as five valves per cylinder to improve efficiency.
The 16.4 operates with a, meaning that two cylinder layouts are positioned next to each other to create the W shape sharing the same crankshaft.The largest internal combustion engine ever built is the, a 14-cylinder, 2-stroke turbocharged diesel engine that was designed to power the, the largest container ship in the world when launched in 2006. This engine has a mass of 2,300 tonnes, and when running at 102 RPM (1.7 Hz) produces over 80 MW, and can use up to 250 tonnes of fuel per day.Types An engine can be put into a category according to two criteria: the form of energy it accepts in order to create motion, and the type of motion it outputs.Heat engine. Main article:An external combustion engine (EC engine) is a where an internal working is heated by combustion of an external source, through the engine wall or a. The then, by expanding and acting on the of the engine produces motion and usable.
The fluid is then cooled, compressed and reused (closed cycle), or (less commonly) dumped, and cool fluid pulled in (open cycle air engine).' ' refers to fuel with an, to supply the heat.
Engines of similar (or even identical) configuration and operation may use a supply of heat from other sources such as nuclear, solar, geothermal or exothermic reactions not involving combustion; but are not then strictly classed as external combustion engines, but as external thermal engines.The working fluid can be a gas as in a, or as in a steam engine or an organic liquid such as n-pentane in an. The fluid can be of any composition; gas is by far the most common, although even single-phase is sometimes used. In the case of the steam engine, the fluid changes between liquid and gas.Air-breathing combustion engines Air-breathing combustion engines are combustion engines that use the in atmospheric air to ('burn') the fuel, rather than carrying an, as in a. Theoretically, this should result in a better than for rocket engines.A continuous stream of air flows through the air-breathing engine. This air is compressed, mixed with fuel, ignited and expelled as the.ExamplesTypical air-breathing engines include:. /.Environmental effects The operation of engines typically has a negative impact upon and ambient.
There has been a growing emphasis on the pollution producing features of automotive power systems. This has created new interest in alternate power sources and internal-combustion engine refinements. Though a few limited-production battery-powered electric vehicles have appeared, they have not proved competitive owing to costs and operating characteristics. In the 21st century the diesel engine has been increasing in popularity with automobile owners. However, the gasoline engine and the Diesel engine, with their new emission-control devices to improve emission performance, have not yet been significantly challenged. A number of manufacturers have introduced hybrid engines, mainly involving a small gasoline engine coupled with an electric motor and with a large battery bank, but these too have yet to make much of an inroad into the market shares of gasoline and Diesel engines.Air quality from a spark ignition engine consists of the following: 70 to 75% (by volume), 10 to 12%, 10 to 13.5%, 0.5 to 2%, 0.2 to 2%,: 0.1 to 6%, unburnt and partial products (e.g. ) 0.5 to 1%, 0.01 to 0.4%.
Main article:Some engines convert heat from noncombustive processes into mechanical work, for example a nuclear power plant uses the heat from the nuclear reaction to produce steam and drive a steam engine, or a gas turbine in a rocket engine may be driven by decomposing. Apart from the different energy source, the engine is often engineered much the same as an internal or external combustion engine. Another group of noncombustive engines includes (sometimes called 'TA engines') which are thermoacoustic devices which use high-amplitude sound waves to pump heat from one place to another, or conversely use a heat difference to induce high-amplitude sound waves. In general, thermoacoustic engines can be divided into standing wave and travelling wave devices.
Non-thermal chemically powered motor Non-thermal motors usually are powered by a chemical reaction, but are not heat engines. Examples include:. – motors found in living things.Electric motor. Main articles: andAn electric motor uses to produce, usually through the interaction of. The reverse process, producing electrical energy from mechanical energy, is accomplished by a. Used on vehicles often perform both tasks.
Electric motors can be run as generators and vice versa, although this is not always practical.Electric motors are ubiquitous, being found in applications as diverse as industrial fans, blowers and pumps, machine tools, household appliances,. They may be powered by direct current (for example a powered portable device or motor vehicle), or by from a central electrical distribution grid. The smallest motors may be found in electric wristwatches. Medium-size motors of highly standardized dimensions and characteristics provide convenient mechanical power for industrial uses. The very largest electric motors are used for propulsion of large ships, and for such purposes as pipeline compressors, with ratings in the thousands of. Electric motors may be classified by the source of electric power, by their internal construction, and by their application.The physical principle of production of mechanical force by the interactions of an electric current and a magnetic field was known as early as 1821.
Electric motors of increasing efficiency were constructed throughout the 19th century, but commercial exploitation of electric motors on a large scale required efficient electrical generators and electrical distribution networks.To reduce the electric from motors and their associated, various regulatory authorities in many countries have introduced and implemented legislation to encourage the manufacture and use of higher efficiency electric motors. A well-designed motor can convert over 90% of its input energy into useful power for decades. When the efficiency of a motor is raised by even a few percentage points, the savings, in (and therefore in cost), are enormous. The electrical energy efficiency of a typical industrial can be improved by: 1) reducing the electrical losses in the windings (e.g., by increasing the cross-sectional area of the, improving the technique, and using materials with higher, such as ), 2) reducing the electrical losses in the coil or casting (e.g., by using materials with higher electrical conductivities, such as copper), 3) reducing magnetic losses by using better quality magnetic, 4) improving the of motors to reduce mechanical windage losses, 5) improving to reduce, and 6) minimizing manufacturing. For further discussion on this subject, see.)By convention, electric engine refers to a railroad, rather than an electric motor.Physically powered motor Some motors are powered by potential or kinetic energy, for example some, and have used the energy from moving water or rocks, and some clocks have a weight that falls under gravity.
Other forms of potential energy include compressed gases (such as ), springs and.Historic included large, and (to some extent) were powered by potential energy.Pneumatic motor. Main article:A pneumatic motor is a machine that converts potential energy in the form of into. Pneumatic motors generally convert the compressed air to mechanical work through either linear or rotary motion. Linear motion can come from either a diaphragm or piston actuator, while rotary motion is supplied by either a vane type air motor or piston air motor. Pneumatic motors have found widespread success in the hand-held tool industry and continual attempts are being made to expand their use to the transportation industry. However, pneumatic motors must overcome efficiency deficiencies before being seen as a viable option in the transportation industry.Hydraulic motor.
Main article:Depending on the type of engine employed, different rates of efficiency are attained.For heat engines, efficiency cannot be greater than the.Sound levels In the case of sound levels, engine operation is of greatest impact with respect to mobile sources such as automobiles and trucks. Engine noise is a particularly large component of mobile source noise for vehicles operating at lower speeds, where aerodynamic and tire noise is less significant.
Generally speaking, petrol (gasoline) and diesel engines emit less noise than turboshafts of equivalent power output; electric motors very often emit less noise than their fossil fuel-powered equivalents. Thrust-outputting engines, such as turbofans, turbojets and rockets emit the greatest amount of noise because their method of producing thrust is directly related to the production of sound.Various methods have been devised to reduce noise. Petrol and diesel engines are fitted with (silencers); newer turbofans often have outsized fans (the so-called high-bypass technology) in order to reduce the proportion of noisy, hot exhaust from the integrated turboshaft in the exhaust stream, and hushkits exist for older, low-bypass turbofans. No known methods exist for reducing the noise output of rockets without a corresponding reduction in thrust.Engines by use Particularly notable kinds of engines include.
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