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Variable Geometry Turbocharger
Variable-geometry turbochargers (VGTs), occasionally known as variable-nozzle turbines (VNTs), are a type of turbochargers, usually designed to allow the effective aspect ratio of the turbocharger to be altered as conditions change. This is done with the use of adjustable vanes located inside the turbine housing between the inlet and turbine, these vanes affect flow of gases towards the turbine. The benefit of the VGT is that the optimum aspect ratio at low engine speeds is very different from that at high engine speeds. If the aspect ratio is too large, the turbo will fail to create boost at low speeds; if the aspect ratio is too small, the turbo will choke the engine at high speeds, leading to high exhaust manifold pressures, high pumping losses, and ultimately lower power output. By altering the geometry of the turbine housing as the engine accelerates, the turbo's aspect ratio can be maintained at its optimum. Because of this, VGTs have a minimal amount of lag, a low boost ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Power-to-weight Ratio
Power-to-weight ratio (PWR, also called specific power, or power-to-mass ratio) is a calculation commonly applied to engines and mobile power sources to enable the comparison of one unit or design to another. Power-to-weight ratio is a measurement of actual performance of any engine or power source. It is also used as a measurement of performance of a vehicle as a whole, with the engine's power output being divided by the weight (or mass) of the vehicle, to give a metric that is independent of the vehicle's size. Power-to-weight is often quoted by manufacturers at the peak value, but the actual value may vary in use and variations will affect performance. The inverse of power-to-weight, weight-to-power ratio (power loading) is a calculation commonly applied to aircraft, cars, and vehicles in general, to enable the comparison of one vehicle's performance to another. Power-to-weight ratio is equal to thrust per unit mass multiplied by the velocity of any vehicle. Power-to-weight ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mitsubishi Heavy Industries
is a Japanese multinational engineering, electrical equipment and electronics corporation headquartered in Tokyo, Japan. MHI is one of the core companies of the Mitsubishi Group and its automobile division is the predecessor of Mitsubishi Motors. MHI's products include aerospace and automotive components, air conditioners, elevators, forklift trucks, hydraulic equipment, printing machines, missiles, tanks, power systems, ships, aircraft, railway systems, and space launch vehicles. Through its defense-related activities, it is the world's 23rd-largest defense contractor measured by 2011 defense revenues and the largest based in Japan. History In 1857, at the request of the Tokugawa Shogunate, a group of Dutch engineers were invited, including Dutch naval engineer Hendrik Hardes, and began work on the ''Nagasaki Yotetsusho'' 長崎鎔鉄所 , a modern, Western-style foundry and shipyard near the Dutch settlement of Dejima, at Nagasaki. This was renamed ''Nagasaki Seit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BorgWarner
BorgWarner Inc. is an American automotive supplier headquartered in Auburn Hills, Michigan. The company maintains production facilities and technical systems at 93 sites (as of June 6, 2022) in 22 countries worldwide and has around 49,000 employees. BorgWarner is one of the 25 largest automotive suppliers in the world. Frédéric Lissalde has been CEO of BorgWarner Inc. since August 1, 2018. The company was formed in 1928 as Borg-Warner Corporation. It was formed as a fusion of companies including Borg & Beck, Marvel-Schebler, Warner Gear and Mechanics Universal Joint Mechanics (from Ancient Greek: μηχανική, ''mēkhanikḗ'', "of machines") is the area of mathematics and physics concerned with the relationships between force, matter, and motion among physical objects. Forces applied to objects res .... In 1987, Borg-Warner Corporation ceased to exist as a result of a series of complex financial transactions, although a new company of the same name (still Borg- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Self-cleaning Oven
A self-cleaning or pyrolytic oven is an oven which uses high temperature (approximately ) to burn off leftovers from baking, without the use of any chemical agents. The oven can be powered by domestic (non-commercial) electricity or gas. Pyrolytic process Self-cleaning pyrolytic ovens reduce food soiling to ash with exposure to temperature around . The oven walls are coated with heat- and acid-resistant porcelain enamel. The safety of self-cleaning ovens has been widely debated. A self-cleaning oven is designed to stay locked until the high temperature process is completed. To prevent possible burn injuries, a mechanical interlock is used to keep the oven door locked and closed during and immediately after the high-temperature cleaning cycle, which lasts approximately three hours. Usually, the door can be opened after the temperature cools to approximately . Self-cleaning ovens usually have more insulation than standard ovens to reduce the possibility of fire. The insulation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diesel Particulate Filter
A diesel particulate filter (DPF) is a device designed to remove diesel particulate matter or soot from the exhaust gas of a diesel engine.Tom Nash (May 2003) "Diesels: The Smoke is clearing", ''Motor '' Vol.199 No. 5, p. 54, Hearst Business Publishing Inc. Mode of action Wall-flow diesel particulate filters usually remove 85% or more of the soot, and under certain conditions can attain soot removal efficiencies approaching 100%. Some filters are single-use, intended for disposal and replacement once full of accumulated ash. Others are designed to burn off the accumulated particulate either passively through the use of a catalyst or by active means such as a fuel burner which heats the filter to soot combustion temperatures. This is accomplished by engine programming to run (when the filter is full) in a manner that elevates exhaust temperature, in conjunction with an extra fuel injector in the exhaust stream that injects fuel to react with a catalyst element to burn off accumulat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exhaust Brake
An exhaust brake is a means of slowing a diesel engine by closing off the exhaust path from the engine, causing the exhaust gases to be compressed in the exhaust manifold, and in the cylinder. Since the exhaust is being compressed, and there is no fuel being applied, the engine slows down the vehicle. The amount of negative torque generated is usually directly proportional to the back pressure of the engine. An exhaust brake is a device that essentially creates a major restriction in the exhaust system, and creates substantial exhaust back pressure to retard engine speed and offer some supplemental braking. In most cases, an exhaust brake is so effective that it can slow a heavily loaded vehicle on a downgrade without ever applying the vehicle's service brakes. Exhaust brakes are manufactured by many companies. The brakes vary in design, but essentially operate as described above. More advanced exhaust brakes have exhaust pressure modulation (EPM) that controls the back pressure wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fuel Efficiency
Fuel efficiency is a form of thermal efficiency, meaning the ratio of effort to result of a process that converts chemical potential energy contained in a carrier (fuel) into kinetic energy or work. Overall fuel efficiency may vary per device, which in turn may vary per application, and this spectrum of variance is often illustrated as a continuous energy profile. Non-transportation applications, such as industry, benefit from increased fuel efficiency, especially fossil fuel power plants or industries dealing with combustion, such as ammonia production during the Haber process. In the context of transport, fuel economy is the energy efficiency of a particular vehicle, given as a ratio of distance traveled per unit of fuel consumed. It is dependent on several factors including engine efficiency, transmission design, and tire design. In most countries, using the metric system, fuel economy is stated as "fuel consumption" in liters per 100 kilometers (L/100 km) or k ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Backpressure
Back pressure (or backpressure) is a resistance or force opposing the desired flow of fluid through pipes, leading to friction loss and pressure drop. The term ''back pressure'' is a misnomer, as pressure is a scalar quantity, so it has a magnitude but no direction. The fluid is what is directed, tending to flow away from high-pressure regions and toward low-pressure regions. If the low-pressure space is more high-pressure than intended (e.g. due to obstructions or tight bends in an exhaust pipe) or the high-pressure space is more low-pressure than intended, this opposes the desired flow and reduces the discharge. Similarly, bending or other operations on a pipe (such as a stock car exhaust system with a particularly high number of twists and bends) can reduce flow rate. Explanation A common example of backpressure is that caused by the exhaust system (consisting of the exhaust manifold, catalytic converter, muffler and connecting pipes) of an automotive four-stroke engine, w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exhaust Gas Recirculation
In internal combustion engines, exhaust gas recirculation (EGR) is a nitrogen oxide () emissions reduction technique used in petrol/gasoline, diesel engines and some hydrogen engines. EGR works by recirculating a portion of an engine's exhaust gas back to the engine cylinders. The exhaust gas displaces atmospheric air and reduces in the combustion chamber. Reducing the amount of oxygen reduces the amount of fuel that can burn in the cylinder thereby reducing peak in-cylinder temperatures. The actual amount of recirculated exhaust gas varies with the engine operating parameters. In the combustion cylinder, is produced by high-temperature mixtures of atmospheric nitrogen and oxygen, and this usually occurs at cylinder peak pressure. In a spark-ignition engine, an ancillary benefit of recirculating exhaust gases via an external EGR valve is an increase in efficiency, as charge dilution allows a larger throttle position and reduces associated pumping losses. Mazda's turbocharged ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charge Cooling
An intercooler is a heat exchanger used to cool a gas after compression. Often found in turbocharged engines, intercoolers are also used in air compressors, air conditioners, refrigeration and gas turbines. Internal combustion engines Most commonly used with turbocharged engines, an intercooler is used to counteract the heat of compression and heat soak in the pressurised intake air. By reducing the temperature of the intake air, the air becomes denser (allowing more fuel to be injected, resulting in increased power) and less likely to suffer from pre-ignition or knocking. Additional cooling can be provided by externally spraying a fine mist onto the intercooler surface, or even into the intake air itself, to further reduce intake charge temperature through evaporative cooling. Intercoolers can vary dramatically in size, shape and design, depending on the performance and space requirements of the system. Many passenger cars use either ''front-mounted intercoolers'' loc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wastegate
A wastegate is a valve that controls the flow of exhaust gases to the turbine wheel in a turbocharged engine system.Robson, D. (2018). Aircraft General Knowledge. Aviation Theory Centre Pty Ltd. . Diversion of exhaust gases regulates the turbine speed, which in turn regulates the rotating speed of the compressor. The primary function of the wastegate is to regulate the maximum boost pressure in turbocharger systems, to protect the engine and the turbocharger. One advantage of installing a remote mount wastegate to a free-float (or non-WG) turbo includes allowance for a smaller A/R turbine housing, resulting in less lag time before the turbo begins to spool and create boost. Wastegate types External An external wastegate is a separate self-contained mechanism typically used with turbochargers that do not have internal wastegates. An external wastegate requires a specially constructed turbo manifold with a dedicated runner going to the wastegate. The external wastegate may be par ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
