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Variable Compression Ratio
Variable compression ratio (VCR) is a technology to adjust the compression ratio of an internal combustion engine while the engine is in operation. This is done to increase fuel efficiency while under varying loads. Variable compression engines allow the volume above the piston at top dead centre to be changed. Higher loads require lower ratios to increase power, while lower loads need higher ratios to increase efficiency, i.e. to lower fuel consumption. For automotive use this needs to be done as the engine is running in response to the load and driving demands. The 2019 Infiniti QX50 is the first commercially available vehicle that uses a variable compression ratio engine. Advantages Gasoline engines have a limit on the maximum pressure during the compression stroke, after which the fuel/air mixture detonates rather than burns. To achieve higher power outputs at the same speed, more fuel must be burned and therefore more air is needed. To achieve this, turbochargers or supe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compression Ratio
The compression ratio is the ratio between the maximum and minimum volume during the compression stage of the power cycle in a piston or Wankel engine. A fundamental specification for such engines, it can be measured in two different ways. The simpler way is the static compression ratio: in a reciprocating engine, this is the ratio of the volume of the cylinder when the piston is at the bottom of its stroke to that volume when the piston is at the top of its stroke. The dynamic compression ratio is a more advanced calculation which also takes into account gases entering and exiting the cylinder during the compression phase. Effect and typical ratios A high compression ratio is desirable because it allows an engine to extract more mechanical energy from a given mass of air–fuel mixture due to its higher thermal efficiency. This occurs because internal combustion engines are heat engines, and higher compression ratios permit the same combustion temperature to be reached wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Combustion Chamber
A combustion chamber is part of an internal combustion engine in which the air–fuel ratio, fuel/air mix is burned. For steam engines, the term has also been used for an extension of the Firebox (steam engine), firebox which is used to allow a more complete combustion process. Internal combustion engines In an internal combustion engine, the pressure caused by the burning air/fuel mixture applies direct force to part of the engine (e.g. for a piston engine, the force is applied to the top of the piston), which converts the gas pressure into mechanical energy (often in the form of a rotating output shaft). This contrasts an external combustion engine, where the combustion takes place in a separate part of the engine to where the gas pressure is converted into mechanical energy. Spark-ignition engines In spark ignition engines, such as petrol engine, petrol (gasoline) engines, the combustion chamber is usually located in the cylinder head. The engines are often designed such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diesel Engine
The diesel engine, named after the German engineer Rudolf Diesel, is an internal combustion engine in which Combustion, ignition of diesel fuel is caused by the elevated temperature of the air in the cylinder due to Mechanics, mechanical Compression (physics), compression; thus, the diesel engine is called a compression-ignition engine (CI engine). This contrasts with engines using spark plug-ignition of the air-fuel mixture, such as a petrol engine (gasoline engine) or a gas engine (using a gaseous fuel like natural gas or liquefied petroleum gas). Introduction Diesel engines work by compressing only air, or air combined with residual combustion gases from the exhaust (known as exhaust gas recirculation, "EGR"). Air is inducted into the chamber during the intake stroke, and compressed during the compression stroke. This increases air temperature inside the Cylinder (engine), cylinder so that atomised diesel fuel injected into the combustion chamber ignites. The torque a dies ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Petrol
Gasoline (North American English) or petrol ( Commonwealth English) is a petrochemical product characterized as a transparent, yellowish, and flammable liquid normally used as a fuel for spark-ignited internal combustion engines. When formulated as a fuel for engines, gasoline is chemically composed of organic compounds derived from the fractional distillation of petroleum and later chemically enhanced with gasoline additives. It is a high-volume profitable product produced in crude oil refineries. The ability of a particular gasoline blend to resist premature ignition (which causes knocking and reduces efficiency in reciprocating engines) is measured by its octane rating. Tetraethyl lead was once widely used to increase the octane rating but is not used in modern automotive gasoline due to the health hazard. Aviation, off-road motor vehicles, and racing car engines still use leaded gasolines. Other substances are frequently added to gasoline to improve chemical stabilit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saab Variable Compression Engine
The Saab Variable Compression engine was a development project of Saab Automobile, for which it won an award both in 2000 and 2001. In a normal internal combustion engine, because cylinder bore diameter, piston stroke length and combustion chamber volume are almost always constant, the compression ratio (CR) for a given engine is almost always constant. One exception is the experimental Saab Variable Compression (SVC) engine, designed for the Saab 9-5. This engine uses a technique that dynamically alters the volume of the combustion chamber, thus changing the compression ratio. To alter the combustion chamber volume, the SVC 'lowers' the cylinder head closer to the crankshaft. It does this by replacing the typical one-part engine block with a two-part block, with the crankshaft in the lower block and the cylinders in the upper portion. The two blocks are hinged together at one side. By pivoting the upper block around the hinge point, the volume of the combustion chamber can be mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schema MCE5
Schema may refer to: Science and technology * SCHEMA (bioinformatics), an algorithm used in protein engineering * Schema (genetic algorithms), a set of programs or bit strings that have some genotypic similarity * Schema.org, a web markup vocabulary * Schema (logic) ** Axiom schema, in formal logic * Image schema, a recurring pattern of spatial sensory experience * Database schema * XML schema Other * Body schema, a neural representation of one's own bodily posture * Galant Schemata, stock phrases in Galant music * Schema (Kant), in philosophy * Schema (psychology), a mental set or representation * Schema Records, a jazz record label in Milan, Italy *, a solemn vow of asceticism of a monk in Orthodox monasticism ** Great Schema, the highest degree of Orthodox monasticism * ''Schema'' (fly), a genus of insects See also * Scheme (other) * Schematic * Skema (other) SKEMA Business School ("School of Knowledge Economy and Management") is a leading French busin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Renault
Renault S.A., commonly referred to as Groupe Renault ( , , , also known as the Renault Group in English), is a French Multinational corporation, multinational Automotive industry, automobile manufacturer established in 1899. The company currently produces a range of cars and vans. It has manufactured trucks, tractors, tanks, buses/coaches, aircraft and aircraft engines, as well as autorail vehicles. Headquartered in Boulogne-Billancourt, near Paris, the Renault group is made up of the namesake Renault marque along with subsidiaries Automobiles Alpine, Alpine, Automobile Dacia, Dacia from Romania, and Mobilize (marque), Mobilize. It is part of Renault–Nissan–Mitsubishi Alliance (previously Renault–Nissan Alliance) since 1999. The French state and Nissan each own a 15% share of the company. Renault also has other subsidiaries such as RCI Banque (automotive financing), Renault Retail Group (automotive distribution), and Motrio (automotive parts). Renault has various joint ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Citroën
Citroën ()The double-dot diacritic over the 'e' is a diaeresis () indicating the two vowels are sounded separately, and not as a diphthong. is a French automobile brand. The "Automobiles Citroën" manufacturing company was founded on 4 June 1919 by André Citroën. Citroën has been owned by Stellantis since 2021 and previously was part of the PSA Group after Peugeot acquired 89.95% share in 1976. Citroën's head office is located in the Stellantis Poissy Plant in Saint-Ouen-sur-Seine since 2021 (previously in Rueil-Malmaison) and its offices studies and research in Vélizy-Villacoublay, Poissy (CEMR), Carrières-sous-Poissy and Sochaux-Montbéliard. In 1934, the firm established its reputation for innovative technology with the Citroën Traction Avant, Traction Avant. This was the world's first car to be mass-produced with front-wheel drive and four-wheel independent suspension, as well as unibody construction, omitting a separate chassis, and instead using the body of the car ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peugeot
Peugeot (, , ) is a French automobile brand owned by Stellantis. The family business that preceded the current Peugeot companies was established in 1810, making it the oldest car company in the world. On 20 November 1858, Émile Peugeot applied for the lion trademark. Armand Peugeot (1849–1915) built the company's first vehicle, a Steam car, steam-powered tricycle. In 1886, the company collaborated with Léon Serpollet, followed by the development of an internal combustion car in 1890, which used a Panhard-Daimler-Motoren-Gesellschaft, Daimler engine. The Peugeot family and company are originally from Sochaux, where Peugeot still operates a large manufacturing facility and the Musée de l'Aventure Peugeot, Peugeot Museum. Peugeot vehicles have received numerous international accolades, including six European Car of the Year awards. The brand also boasts over a century of success in motorsport, with victories including the Indianapolis 500 in 1913, 1916, and 1919. Peugeot Spo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volvo
The Volvo Group (; legally Aktiebolaget Volvo, shortened to AB Volvo, stylized as VOLVO) is a Swedish multinational manufacturing corporation headquartered in Gothenburg. While its core activity is the production, distribution and sale of trucks, buses and construction equipment, Volvo also supplies marine and industrial drive systems and financial services. In 2016, it was the world's second-largest manufacturer of heavy-duty trucks with its subsidiary Volvo Trucks. Volvo was founded in 1927. Initially involved in the automobile industry, Volvo expanded into other manufacturing sectors throughout the twentieth century. Automobile manufacturer Volvo Cars, also based in Gothenburg, was part of AB Volvo until 1999, when it was sold to the Ford Motor Company. Since 2010 Volvo Cars has been owned by the automotive company Geely Holding Group. Both AB Volvo and Volvo Cars share the Volvo logo and cooperate in running the Volvo Museum in Gothenburg, Sweden. The corporation was first ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nissan Motors
is a Japanese multinational automobile manufacturer headquartered in Yokohama, Kanagawa, Japan. The company sells its vehicles under the ''Nissan'' and '' Infiniti'' brands, and formerly the ''Datsun'' brand, with in-house performance tuning products (including cars) under the Nismo and Autech brands. The company traces back to the beginnings of the 20th century, with the Nissan '' zaibatsu'' or called Nissan Group. Since 1999, Nissan has been part of the Renault–Nissan–Mitsubishi Alliance (Mitsubishi joining in 2016), a partnership between Nissan and Mitsubishi Motors of Japan, with Renault of France. , Renault holds a 15% voting stake in Nissan, while Nissan holds the same stake in Renault. Since October 2016, Nissan held a 34% controlling stake in Mitsubishi Motors. In November 2024, Nissan reduced its stake in Mitsubishi Motors from 34% to 24%. Nissan planned to merge with Honda Motor Company in 2026, after an announcement in December 2024. However by February 20 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saab Automobile
Saab Automobile AB () was a automotive industry, car manufacturer that was founded in Sweden in 1945 when its parent company, Saab AB, began a project to design a small automobile. The first production model, the Saab 92, was launched in 1949. In 1968, the parent company merged with Scania-Vabis, and ten years later the Saab 900 was launched, in time becoming Saab's best-selling model. In the mid-1980s, the new Saab 9000 model also appeared. In 1989, the automobile division of Saab-Scania was restructured into an independent company, Saab Automobile AB. The American manufacturer General Motors (GM) took 50 percent ownership. Two well-known models to come out of this period were the Saab 9-3 and the Saab 9-5. Then, in 2000, GM exercised its option to acquire the remaining 50 percent. In 2010, GM sold Saab Automobile AB to the Dutch automobile manufacturer Spyker Cars N.V. After many years establishing a sound engineering reputation and ultimately a luxury car, luxury price tag, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
