Rear mid-engine, rear-wheel-drive layout
In automotive design, a RMR or Rear Mid-engine, rear-wheel-drive layout is one in which the rear wheels are driven by an engine placed just in front of them, behind the passenger compartment. In contrast to the rear-engined RR layout, the center of mass of the engine is in front of the rear axle; this layout is chosen for its low moment of inertia and favorable weight distribution. The layout has a tendency toward being heavier in the rear than the front, which allows for best balance to be achieved under braking. However, since there is little weight over the front wheels, under acceleration, the front of the car is prone to lift and cause understeer. Most rear-engine layouts have been used in smaller vehicles, because the weight of the engine at the rear has an adverse effect on a larger car's handling, making it'tail-heavy', it is felt. The mid-engined layout uses up central space, making it impractical for any but two-seater sports cars. However, some microvans use this layout, with a low engine beneath the loading area.
This makes it possible to move the driver right to the front of the vehicle, thus increasing the loading area at the expense of reduced load depth. In modern racing cars, RMR is the usual configuration and is synonymous with "mid engine". Due to its weight distribution and resulting favorable vehicle dynamics, this layout is employed in open-wheel Formula racing cars as well as purpose-built sports racing cars; this configuration was common in small engined 1950s microcars, in which the engines did not take up much space. Because of successes in racing, the RMR platform has been popular for road-going sports cars despite the inherent challenges of design and lack of cargo space; the similar mid-engine, four-wheel-drive layout gives many of the same advantages and is used when extra traction is desired, such as in some supercars and in the Group B rally cars. The 1900 NW Rennzweier was one of the first race cars with rear-wheel-drive layout. Other known historical examples include the 1923 Benz Tropfenwagen.
It was based on an earlier design named the Rumpler Tropfenwagen in 1921 made by Edmund von Rumpler, an Austrian engineer working at Daimler. The Benz Tropfenwagen was designed by Ferdinand Porsche along with Hans Nibel, it raced in 1923 and 1924 and was most successful in the Italian Grand Prix in Monza where it stood fourth. Ferdinand Porsche used mid-engine design concept towards the Auto Union Grand Prix cars of the 1930s which became the first winning RMR racers, they were decades before their time, although MR Miller Specials raced a few times at Indianapolis between 1939 and 1947. In 1953 Porsche premiered the tiny and altogether new RMR 550 Spyder and in a year it was notoriously winning in the smaller sports and endurance race car classes against much larger cars—a sign of greater things to come; the 718 followed in 1958. But it was not until the late 1950s that RMR reappeared in Grand Prix races in the form of the Cooper-Climax, soon followed by cars from BRM and Lotus. Ferrari and Porsche soon made.
The mid-engined layout was brought back to Indianapolis in 1961 by the Cooper Car Company with Jack Brabham running as high as third and finishing ninth. Cooper did not return, but from 1963 on British built mid-engined cars from constructors like Brabham and Lola competed and in 1965 Lotus won Indy with their Type 38. Rear mid-engines were used in microcars like the Isetta or the Zündapp Janus; the first rear mid-engined road car after WW II was the 1962 Bonnet / Matra Djet, which used the 1108cc Renault Sierra engine, mated to the transaxle from the FWD Renault Estafette van. Nearly 1700 were built until 1967; this was followed by the first De Tomaso, the Vallelunga, which mated a tuned Ford Cortina 1500 Kent engine to a VW transaxle with Hewland gearsets. Introduced at Turin in 1963, 58 were built 1964-68. A similar car was the Renault-engined Lotus Europa, built from 1966–1975. In 1966, the Lamborghini Miura was the first high performance mid-engine, rear-wheel-drive roadcar; the concept behind the Miura was that of putting on the road a grand tourer featuring state-of-the-art racing-car technology of the time.
This represented an innovative sportscar at a time when all of its competitors, from Ferraris to Aston Martins, were traditional front-engined, rear wheel drive grand tourers. The Pontiac Fiero was a mid-engined sports car, built by the Pontiac division of General Motors from 1984 to 1988; the Fiero was the first two-seater Pontiac since the 1926 to 1938 coupes, the first and only mass-produced mid-engine sports car by a U. S. manufacturer. Engine and driveline layout considerations
China the People's Republic of China, is a country in East Asia and the world's most populous country, with a population of around 1.404 billion. Covering 9,600,000 square kilometers, it is the third- or fourth-largest country by total area. Governed by the Communist Party of China, the state exercises jurisdiction over 22 provinces, five autonomous regions, four direct-controlled municipalities, the special administrative regions of Hong Kong and Macau. China emerged as one of the world's earliest civilizations, in the fertile basin of the Yellow River in the North China Plain. For millennia, China's political system was based on hereditary monarchies, or dynasties, beginning with the semi-legendary Xia dynasty in 21st century BCE. Since China has expanded, re-unified numerous times. In the 3rd century BCE, the Qin established the first Chinese empire; the succeeding Han dynasty, which ruled from 206 BC until 220 AD, saw some of the most advanced technology at that time, including papermaking and the compass, along with agricultural and medical improvements.
The invention of gunpowder and movable type in the Tang dynasty and Northern Song completed the Four Great Inventions. Tang culture spread in Asia, as the new Silk Route brought traders to as far as Mesopotamia and Horn of Africa. Dynastic rule ended in 1912 with the Xinhai Revolution; the Chinese Civil War resulted in a division of territory in 1949, when the Communist Party of China established the People's Republic of China, a unitary one-party sovereign state on Mainland China, while the Kuomintang-led government retreated to the island of Taiwan. The political status of Taiwan remains disputed. Since the introduction of economic reforms in 1978, China's economy has been one of the world's fastest-growing with annual growth rates above 6 percent. According to the World Bank, China's GDP grew from $150 billion in 1978 to $12.24 trillion by 2017. Since 2010, China has been the world's second-largest economy by nominal GDP and since 2014, the largest economy in the world by purchasing power parity.
China is the world's largest exporter and second-largest importer of goods. China is a recognized nuclear weapons state and has the world's largest standing army and second-largest defense budget; the PRC is a permanent member of the United Nations Security Council as it replaced the ROC in 1971, as well as an active global partner of ASEAN Plus mechanism. China is a leading member of numerous formal and informal multilateral organizations, including the Shanghai Cooperation Organization, WTO, APEC, BRICS, the BCIM, the G20. In recent times, scholars have argued that it will soon be a world superpower, rivaling the United States; the word "China" has been used in English since the 16th century. It is not a word used by the Chinese themselves, it has been traced through Portuguese and Persian back to the Sanskrit word Cīna, used in ancient India."China" appears in Richard Eden's 1555 translation of the 1516 journal of the Portuguese explorer Duarte Barbosa. Barbosa's usage was derived from Persian Chīn, in turn derived from Sanskrit Cīna.
Cīna was first used including the Mahābhārata and the Laws of Manu. In 1655, Martino Martini suggested that the word China is derived from the name of the Qin dynasty. Although this derivation is still given in various sources, it is complicated by the fact that the Sanskrit word appears in pre-Qin literature; the word may have referred to a state such as Yelang. The meaning transferred to China as a whole; the origin of the Sanskrit word is still a matter of debate, according to the Oxford English Dictionary. The official name of the modern state is the "People's Republic of China"; the shorter form is "China" Zhōngguó, from zhōng and guó, a term which developed under the Western Zhou dynasty in reference to its royal demesne. It was applied to the area around Luoyi during the Eastern Zhou and to China's Central Plain before being used as an occasional synonym for the state under the Qing, it was used as a cultural concept to distinguish the Huaxia people from perceived "barbarians". The name Zhongguo is translated as "Middle Kingdom" in English.
Archaeological evidence suggests that early hominids inhabited China between 2.24 million and 250,000 years ago. The hominid fossils of Peking Man, a Homo erectus who used fire, were discovered in a cave at Zhoukoudian near Beijing; the fossilized teeth of Homo sapiens have been discovered in Fuyan Cave in Hunan. Chinese proto-writing existed in Jiahu around 7000 BCE, Damaidi around 6000 BCE, Dadiwan from 5800–5400 BCE, Banpo dating from the 5th millennium BCE; some scholars have suggested. According to Chinese tradition, the first dynasty was the Xia, which emerged around 2100 BCE; the dynasty was considered mythical by historians until scientific excavations found early Bronze Age sites at Erlitou, Henan in 1959. It remains unclear whether these sites are the remains of the Xia dynasty or of another culture from the same period; the succeeding Shang dynasty is the earliest to be confirmed by contemporary records. The Shang ruled the plain of the Yellow River in eastern China from the 17th to the 11th century BCE.
Their oracle bone script
A scale model is most a physical representation of an object, which maintains accurate relationships between all important aspects of the model, although absolute values of the original properties need not be preserved. This enables it to demonstrate some behavior or property of the original object without examining the original object itself; the most familiar scale models represent the physical appearance of an object in miniature, but there are many other kinds. Scale models are used in many fields including engineering, film making, military command and hobby model building. While each field may use a scale model for a different purpose, all scale models are based on the same principles and must meet the same general requirements to be functional; the detail requirements vary depending on the needs of the modeler. To be a true scale model, all relevant aspects must be modeled, such as material properties, so the model's interaction with the outside world is reliably related to the original object's interaction with the real world.
In general a scale model must be designed and built considering similitude theory. However, other requirements concerning practical issues must be considered. Similitude is the art of predicting prototype performance from scale model observations; the main requirement of similitude is all dimensionless quantities must be equal for both the scaled model and the prototype under the conditions the modeler desires to make observations. Dimensionless quantities are referred to as Pi terms, or π terms. In many fields the π terms are well established. For example, in fluid dynamics, a well known dimensionless number called the Reynolds number comes up in scale model tests with fluid in motion relative to a stationary surface. Thus, for a scale model test to be reliable, the Reynolds number, as well as all other important dimensionless quantities, must be equal for both scale model and prototype under the conditions that the modeler wants to observe. An example of the Reynolds number and its use in similitude theory satisfaction can be observed in the scale model testing of fluid flow in a horizontal pipe.
The Reynolds number for the scale model pipe must be equal to the Reynolds number of the prototype pipe for the flow measurements of the scale model to correspond to the prototype in a meaningful way. This can be written mathematically, with the subscript m referring to the scale model and subscript p referring to the prototype, as follows: R e m = ρ m v m L m μ m = ρ p v p L p μ p = R e p where v is the mean velocity of the object relative to the fluid L is a characteristic linear dimension, μ is the dynamic viscosity of the fluid ρ is the density of the fluid. Observing the equation above it is clear to see that while the Reynolds numbers must be equal for the scale model and the prototype, this can be accomplished in many different ways, for example, in this problem by altering the scale of the dynamic viscosity of the model to work with the scale of the length; this means, the scales of different quantities, for example a material's elasticity in the scale model versus the prototype, are governed by equating the dimensionless quantities and the other quantity's scaling within the dimensionless quantity to ensure the dimensionless quantity of interest is of equal magnitude for the scale model and prototype.
With the above understanding of similitude requirements, it becomes clear the scale reported in scale models refers only to the geometric scale, S L, not the scale of the parameters important to consider in the scale model design and fabrication. In general the scale of any quantity i material density or viscosity, is defined as: S i = i p i m where i p is the quantity value of the prototype i m is the quantity value of the scale modelThis relationship must be applied to all quantities of interest in the prototype, observing similitude requirements—so the scale model can be built using dimensions and materials that make scale model testing results meaningful with respect to the prototype. One method to determine the dimensionless quantities of concern for a given problem is to use dimensional analysis. Practical concerns include the cost to construct the model, available test facilities to condition and observe the model, the availability of certain materials, who will build it. Practical requirements are very diverse depending on the purpose of the scale model and they all must be considered to have a successful scale model experience.
As an example an aerospace company needs to test a new wing shape. Acco
Twin-turbo or biturbo refers to a turbocharged engine in which two turbochargers compress the intake charge. The most common layout features two identical turbochargers in parallel. Paralleled twin-turbo refers to the turbocharger configuration in which two identical turbochargers function splitting the turbocharging duties equally; each turbocharger is driven by half of the engine's spent exhaust energy. In most applications, the compressed air from both turbos is combined in a common intake manifold and sent to the individual cylinders; each turbocharger is mounted to its own individual exhaust/turbo manifold, but on inline-type engines both turbochargers can be mounted to a single turbo manifold. Parallel twin turbos applied to V-shaped engines are mounted with one turbo assigned to each cylinder bank, providing packaging symmetry and simplifying plumbing over a single turbo setup; when used on inline engines, parallel twin turbos are applied with two smaller turbos, which can provide similar performance with less turbo lag than a single larger turbo.
Some examples of parallel twin-turbo inline engines are Nissan's RB26DETT, BMW's N54 and Volvo's B6284T and B6294T. The Maserati Biturbo, introduced in 1981 and featuring an aluminium 90-degree SOHC V6, was the first production car with a twin-turbo charged engine. Other examples of V formation engines with parallel twin-turbos include Mitsubishi's 6A12TT, 6A13TT and 6G72TT. While a parallel twin-turbo set-up theoretically has less turbo lag than a single turbocharger set up, this is not always the case due to many factors. Marginally reduced combined inertial resistance, simplified exhaust plumbing, the simultaneous spooling of both turbos means that there can still be a noticeable bit of lag in high-flow turbo/high boost applications; some ways to counter this are to use a light pressure set up with smaller turbos, where the turbos are designed to output less boost but spool earlier. While this setup sacrifices some top end power, it still has less lag than a similar engine with a single turbo set up making the same power.
Another system would be the use of variable geometry turbochargers. This system changes the angle of the guide vanes depending on the exhaust pressure, giving the system excellent power throughout the rev range. Once used in turbocharged diesel engines, Chrysler was the first to use it in mass-production gasoline-powered vehicles with the Shelby CSX, debuted in 1989, it is possible to use parallel operation with more than two turbochargers. Two such examples are the Bugatti EB110 and Bugatti Veyron, both of which run four turbochargers in parallel; the EB110 runs 4 turbos on a 3.5 litre V12 engine, producing 542 hp at 8000 rpm, while the Veyron uses an 8.0 litre 16 cylinder engine to generate 1,001 PS. The Bugatti Veyron Super Sport uses the quad-turbo 8.0 W16 engine that produces 1216 PS. Sequential turbos refer to a set-up in which the engine uses one turbocharger for lower engine speeds, a second or both turbochargers at higher engine speeds. Larger high-flow turbochargers are not as efficient at low RPM, resulting in lower intake manifold pressures under these conditions.
On the other hand, smaller turbos spool up at low RPM but cannot supply enough air at higher engine speed. During low to mid engine speeds, when available spent exhaust energy is minimal, only one small turbocharger is active. During this period, all of the engine's exhaust energy is directed to the primary turbocharger only, providing the small turbo's benefits of a lower boost threshold, minimal turbo lag, increased power output at low engine speeds; as RPM increases, the secondary turbocharger is activated in order to pre-spool prior to its full utilization. Once a preset engine speed or boost pressure is attained, valves controlling compressor and turbine flow through the secondary turbocharger are opened completely. In this way a full twin-turbocharger setup provides the benefits associated with a large turbo, including maximum power output, without the disadvantage of increased turbo lag. Sequential turbocharger systems provide a way to decrease turbo lag without compromising ultimate boost output and engine power.
The most noteworthy application of this system is the fourth-generation Toyota Supra, regarded as having the most reliable sequential turbo system yet fitted to a production automobile, with a reported failure rate of less than 1% as of 2011. Other examples of cars with a sequential twin-turbo setup include the 1986-1988 Porsche 959, the 1990-1995 Eunos Cosmo JC, 1992-2002 Mazda RX-7 FD3S Turbo, the 1994-2005 JDM Subaru Legacy GT, GT-B & B4 RSK, the Peugeot 407 2.2 HDi. GM has filed a patent for a sequential twin-turbo system that uses a new bypass valve design said to optimize exhaust flow to the turbines of both turbochargers. According to the 2016 patent description, the exhaust manifold features two outlets with one directing exhaust gases to the turbine of the high-pressure turbocharger, while the second exhaust manifold outlet directs exhaust gases to the turbine of the low-pressure turbocharger via a connecting channel. Additionally, exhaust gas exiting the high-pressure turbine is directed to the inlet of the low-pressure turbine.
The new bypass system features two throttle valves located on the same spindle mounted perpendicular to each ot
Governments and private organizations have developed car classification schemes that are used for various purposes including regulation and categorization, among others. This article details used classification schemes in use worldwide; this following table summarises common classifications for cars. Microcars and their Japanese equivalent— kei cars— are the smallest category of automobile. Microcars straddle the boundary between car and motorbike, are covered by separate regulations to normal cars, resulting in relaxed requirements for registration and licensing. Engine size is 700 cc or less, microcars have three or four wheels. Microcars are most popular in Europe, where they originated following World War II; the predecessors to micro cars are Cycle cars. Kei cars have been used in Japan since 1949. Examples of microcars and kei cars: Honda Life Isetta Tata Nano The smallest category of vehicles that are registered as normal cars is called A-segment in Europe, or "city car" in Europe and the United States.
The United States Environmental Protection Agency defines this category as "minicompact", however this term is not used. The equivalents of A-segment cars have been produced since the early 1920s, however the category increased in popularity in the late 1950s when the original Fiat 500 and BMC Mini were released. Examples of A-segment / city cars / minicompact cars: Fiat 500 Hyundai i10 Toyota Aygo The next larger category small cars is called B-segment Europe, supermini in the United Kingdom and subcompact in the United States; the size of a subcompact car is defined by the United States Environmental Protection Agency, as having a combined interior and cargo volume of between 85–99 cubic feet. Since the EPA's smaller minicompact category is not as used by the general public, A-segment cars are sometimes called subcompacts in the United States. In Europe and Great Britain, the B-segment and supermini categories do not any formal definitions based on size. Early supermini cars in Great Britain include Vauxhall Chevette.
In the United States, the first locally-built subcompact cars were the 1970 AMC Gremlin, Chevrolet Vega, Ford Pinto. Examples of B-segment / supermini / subcompact cars: Chevrolet Sonic Hyundai Accent Volkswagen Polo The largest category of small cars is called C-segment or small family car in Europe, compact car in the United States; the size of a compact car is defined by the United States Environmental Protection Agency, as having a combined interior and cargo volume of 100–109 cu ft. Examples of C-segment / compact / small family cars: Peugeot 308 Toyota Auris Renault Megane In Europe, the third largest category for passenger cars is called D-segment or large family car. In the United States, the equivalent term is intermediate cars; the U. S. Environmental Protection Agency defines a mid-size car as having a combined passenger and cargo volume of 110–119 cu ft. Examples of D-segment / large family / mid-size cars: Chevrolet Malibu Ford Mondeo Kia Optima In Europe, the second largest category for passenger cars is E-segment / executive car, which are luxury cars.
In other countries, the equivalent terms are full-size car or large car, which are used for affordable large cars that aren't considered luxury cars. Examples of non-luxury full-size cars: Chevrolet Impala Ford Falcon Toyota Avalon Minivan is an American car classification for vehicles which are designed to transport passengers in the rear seating row, have reconfigurable seats in two or three rows; the equivalent terms in British English are people carrier and people mover. Minivans have a'one-box' or'two-box' body configuration, a high roof, a flat floor, a sliding door for rear passengers and high H-point seating. Mini MPV is the smallest size of MPVs and the vehicles are built on the platforms of B-segment hatchback models. Examples of Mini MPVs: Fiat 500L Honda Fit Ford B-Max Compact MPV is the middle size of MPVs; the Compact MPV size class sits between large MPV size classes. Compact MPVs remain predominantly a European phenomenon, although they are built and sold in many Latin American and Asian markets.
Examples of Compact MPVs: Renault Scenic Volkswagen Touran Ford C-Max The largest size of minivans is referred to as'Large MPV' and became popular following the introduction of the 1984 Renault Espace and Dodge Caravan. Since the 1990s, the smaller Compact MPV and Mini MPV sizes of minivans have become popular. If the term'minivan' is used without specifying a size, it refers to a Large MPV. Examples of Large MPVs: Dodge Grand Caravan Ford S-Max Toyota Sienna The premium compact class is the smallest category of luxury cars, it became popular in the mid-2000s, when European manufacturers— such as Audi, BMW and Mercedes-Benz— introduced new entry level models that were smaller and cheaper than their compact executive models. Examples of premium compact cars: Audi A3 Buick Verano Lexus CT200h A compact executive car is a premium car larger than a premium compact and smaller than an executive car. Compact executive cars are equivalent size to mid-size cars and are part of the D-segment in the European car classification.
In North American terms, close equivalents are "luxury compact" and "entry-level luxury car", although the latter is used for the smaller premium compact cars. Examples of compact executive cars: Audi A4 BMW 3 Series Buick Regal An executive car is a premium car larger than a compact executive and smaller than an full-size luxury car. Executive cars are classified as E-segment cars in the European car classification. In the United States and several other coun
Fuel injection is the introduction of fuel in an internal combustion engine, most automotive engines, by the means of an injector. All diesel engines use fuel injection by design. Petrol engines can use gasoline direct injection, where the fuel is directly delivered into the combustion chamber, or indirect injection where the fuel is mixed with air before the intake stroke. On petrol engines, fuel injection replaced carburetors from the 1980s onward; the primary difference between carburetors and fuel injection is that fuel injection atomizes the fuel through a small nozzle under high pressure, while a carburetor relies on suction created by intake air accelerated through a Venturi tube to draw the fuel into the airstream. The functional objectives for fuel injection systems can vary. All share the central task of supplying fuel to the combustion process, but it is a design decision how a particular system is optimized. There are several competing objectives such as: Power output Fuel efficiency Emissions performance Running on alternative fuels Reliability Driveability and smooth operation Initial cost Maintenance cost Diagnostic capability Range of environmental operation Engine tuningModern digital electronic fuel injection systems optimize these competing objectives more and than earlier fuel delivery systems.
Carburetors have the potential to atomize fuel better. Benefits of fuel injection include smoother and more consistent transient throttle response, such as during quick throttle transitions, easier cold starting, more accurate adjustment to account for extremes of ambient temperatures and changes in air pressure, more stable idling, decreased maintenance needs, better fuel efficiency. Fuel injection dispenses with the need for a separate mechanical choke, which on carburetor-equipped vehicles must be adjusted as the engine warms up to normal temperature. Furthermore, on spark ignition engines, fuel injection has the advantage of being able to facilitate stratified combustion which have not been possible with carburetors, it is only with the advent of multi-point fuel injection certain engine configurations such as inline five cylinder gasoline engines have become more feasible for mass production, as traditional carburetor arrangement with single or twin carburetors could not provide fuel distribution between cylinders, unless a more complicated individual carburetor per cylinder is used.
Fuel injection systems are able to operate regardless of orientation, whereas carburetors with floats are not able to operate upside down or in microgravity, such as encountered on airplanes. Fuel injection increases engine fuel efficiency. With the improved cylinder-to-cylinder fuel distribution of multi-point fuel injection, less fuel is needed for the same power output. Exhaust emissions are cleaner because the more precise and accurate fuel metering reduces the concentration of toxic combustion byproducts leaving the engine; the more consistent and predictable composition of the exhaust makes emissions control devices such as catalytic converters more effective and easier to design. Herbert Akroyd Stuart developed the first device with a design similar to modern fuel injection, using a'jerk pump' to meter out fuel oil at high pressure to an injector; this system was used on the hot-bulb engine and was adapted and improved by Bosch and Clessie Cummins for use on diesel engines. Fuel injection was in widespread commercial use in diesel engines by the mid-1920s.
An early use of indirect gasoline injection dates back to 1902, when French aviation engineer Leon Levavasseur installed it on his pioneering Antoinette 8V aircraft powerplant, the first V8 engine of any type produced in any quantity. Another early use of gasoline direct injection was on the Hesselman engine invented by Swedish engineer Jonas Hesselman in 1925. Hesselman engines use the ultra lean-burn principle, they are started on gasoline and switched to diesel or kerosene. Direct fuel injection was used in notable World War II aero-engines such as the Junkers Jumo 210, the Daimler-Benz DB 601, the BMW 801, the Shvetsov ASh-82FN. German direct injection petrol engines used injection systems developed by Bosch from their diesel injection systems. Versions of the Rolls-Royce Merlin and Wright R-3350 used single point fuel injection, at the time called "Pressure Carburettor". Due to the wartime relationship between Germany and Japan, Mitsubishi had two radial aircraft engines using fuel injection, the Mitsubishi Kinsei and the Mitsubishi Kasei.
Alfa Romeo tested one of the first electronic injection systems in Alfa Romeo 6C 2500 with "Ala spessa" body in 1940 Mille Miglia. The engine had six electrically operated injectors and were fed by a semi-high-pressure circulating fuel pump system. All diesel engines have fuel injected into the combustion chamber. See Diesel engine; the invention of mechanical injection for gasoline-fueled aviation engines was by the French inventor of the V8 engine configuration, Leon Levavasseur in 1902. Levavasseur designed the original Antoinette firm's series of V-form aircraft engines, starting with the Antoinette 8V to be used by the aircraft the Antoinette firm built that Levavasseur designed, flown from 1906 to the firm's demise in 1910, with t
An intercooler is a mechanical device used to cool a gas after compression process, Compression process increases the internal energy of the gas which in turn raises its temperature and reduces the density. In other words intercooler is a device used in compression process a heat exchanger that removes waste heat in a gas compressor, they are used in many applications, including air compressors, air conditioners and gas turbines, automotive engines. Here they are known as an air-to-air or air-to-liquid cooler for forced induction internal combustion engines to improve their volumetric efficiency, which they do by increasing intake air density through nearly constant pressure cooling. Intercoolers are utilized to remove the waste heat from the first stage of two-stage air compressors. Two-stage air compressors are manufactured because of their inherent efficiency; the cooling action of the intercooler is principally responsible for this higher efficiency, bringing it closer to Carnot efficiency.
Removing the heat-of-compression from the discharge of the first stage has the effect of densifying the air charge. This, in turn, allows the second stage to produce more work from its fixed compression ratio. Adding an intercooler to the setup requires additional investments. Intercoolers increase the efficiency of the induction system by reducing induction air heat created by the supercharger or turbocharger and promoting more thorough combustion; this removes the heat of compression. A decrease in intake air charge temperature sustains use of a more dense intake charge into the engine, as a result of forced induction; the lowering of the intake charge air temperature eliminates the danger of pre-detonation of the fuel/air charge prior to timed spark ignition. This preserves the benefits of more fuel/air burn per engine cycle, increasing the output of the engine. Intercoolers eliminate the need for using the wasteful method of lowering intake charge temperature by the injection of excess fuel into the cylinders' air induction chambers, to cool the intake air charge, prior to its flowing into the cylinders.
This wasteful practice nearly eliminated the gain in engine efficiency from forced induction, but was necessitated by the greater need to prevent at all costs the engine damage that pre-detonation engine knocking causes. The inter prefix in the device name originates from its use as a cooler in between compression cycles. In automobiles the intercooler is placed between the turbocharger and the engine. Aircraft engines are sometimes built with charge air coolers that were installed between multiple stages of forced induction, thus the designation of inter. In a vehicle fitted with two-stage turbocharging, it is possible to have both an intercooler and an aftercooler; the JCB Dieselmax land speed record-holding car is an example of such a system. In general, an intercooler or aftercooler is said to be a charge-air cooler. Intercoolers can vary in size and design, depending on the performance and space requirements of the entire supercharger system. Common spatial designs are front mounted intercoolers, top mounted intercoolers and hybrid mount intercoolers.
Each type can be cooled with air-to-liquid system, or a combination of both. Turbochargers and superchargers are engineered to force more air mass into an engine's intake manifold and combustion chamber. Intercooling is a method used to compensate for heating caused by supercharging, a natural byproduct of the semi-adiabatic compression process. Increased air pressure can result in an excessively hot intake charge reducing the performance gains of supercharging due to decreased density. Increased intake charge temperature can increase the cylinder combustion temperature, causing detonation, excessive wear, or heat damage to an engine block or pistons. Passing a compressed and heated intake charge through an intercooler reduces its temperature and pressure. If the device is properly engineered, the relative decrease in temperature is greater than the relative loss in pressure, resulting in a net increase in density; this increases system performance by recovering some losses of the inefficient compression process by rejecting heat to the atmosphere.
Additional cooling can be provided by externally spraying a fine mist onto the intercooler surface, or into the intake air itself, to further reduce intake charge temperature through evaporative cooling. Intercoolers that exchange their heat directly with the atmosphere are designed to be mounted in areas of an automobile with maximum air flow; these types are mounted in front mounted systems. Cars such as the Nissan Skyline, Volvo 200 Series Turbo, Volvo 700 Series turbo, Dodge SRT-4, 1st gen Mazda MX-6, Mitsubishi Lancer Evolution and Chevrolet Cobalt SS all use front mounted intercooler mounted near the front bumper, in line with the car's radiator. Many other turbo-charged cars where the aesthetics of the car are not to be compromised by top mount scoops, such as the Toyota Supra, Nissan 300ZX Twin Turbo, Nissan Silvia, Nissan 180sx, Mitsubishi 3000gt, Saab 900, Fiat Turbo diesels, Audi TT, Turbo Mitsubishi Eclipse use side-mounted air-to-air intercoolers, which are mounted in the f