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40-396: A turbo-compound engine is a reciprocating engine that employs a turbine to recover energy from the exhaust gases. Instead of using that energy to drive a turbocharger as found in many high-power aircraft engines , the energy is instead sent to the output shaft to increase the total power delivered by the engine. The turbine is usually mechanically connected to the crankshaft , as on

80-597: A capacity of 1,820 L (64 cu ft), making a total capacity of 25,480 L (900 cu ft) for the largest versions. For piston engines, an engine's capacity is the engine displacement , in other words the volume swept by all the pistons of an engine in a single movement. It is generally measured in litres (l) or cubic inches (c.i.d., cu in, or in ) for larger engines, and cubic centimetres (abbreviated cc) for smaller engines. All else being equal, engines with greater capacities are more powerful and consumption of fuel increases accordingly (although this

120-698: A circular groove in the piston head. The rings fit closely in the groove and press lightly against the cylinder wall to form a seal, and more heavily when higher combustion pressure moves around to their inner surfaces. It is common to classify such engines by the number and alignment of cylinders and total volume of displacement of gas by the pistons moving in the cylinders usually measured in cubic centimetres (cm or cc) or litres (l) or (L) (US: liter). For example, for internal combustion engines, single and two-cylinder designs are common in smaller vehicles such as motorcycles , while automobiles typically have between four and eight, and locomotives and ships may have

160-469: A cylinder to drive a reciprocating engine in a local-pollution-free urban vehicle. Torpedoes may use a working gas produced by high test peroxide or Otto fuel II , which pressurize without combustion. The 230 kg (510 lb) Mark 46 torpedo , for example, can travel 11 km (6.8 mi) underwater at 74 km/h (46 mph) fuelled by Otto fuel without oxidant . Quantum heat engines are devices that generate power from heat that flows from

200-418: A dozen cylinders or more. Cylinder capacities may range from 10 cm or less in model engines up to thousands of liters in ships' engines. The compression ratio affects the performance in most types of reciprocating engine. It is the ratio between the volume of the cylinder, when the piston is at the bottom of its stroke, and the volume when the piston is at the top of its stroke. The bore/stroke ratio

240-415: A gas is introduced, either already under pressure (e.g. steam engine ), or heated inside the cylinder either by ignition of a fuel air mixture ( internal combustion engine ) or by contact with a hot heat exchanger in the cylinder ( Stirling engine ). The hot gases expand, pushing the piston to the bottom of the cylinder. This position is also known as the bottom dead center (BDC), or where the piston forms

280-406: A hot to a cold reservoir. The mechanism of operation of the engine can be described by the laws of quantum mechanics . Quantum refrigerators are devices that consume power with the purpose to pump heat from a cold to a hot reservoir. In a reciprocating quantum heat engine, the working medium is a quantum system such as spin systems or a harmonic oscillator. The Carnot cycle and Otto cycle are

320-538: A large number of unusual varieties of piston engines that have various claimed advantages, many of which see little if any current use: Detroit Diesel Detroit Diesel Corporation (DDC) is an American diesel engine manufacturer headquartered in Detroit, Michigan . It is a subsidiary of Daimler Truck North America , which is itself a wholly owned subsidiary of the multinational Daimler Truck AG . The company manufactures heavy-duty engines and chassis components for

360-428: A lower-pressure, slower-moving stream. This action has the side-effect of increasing the upstream pressure, which makes it undesirable for use with a piston engine as it increases the back-pressure in the engine, which decreases scavenging of the exhaust gas from the cylinders and thereby lowers the efficiency of the piston portion of a compound engine. Through the late 1930s and early 1940s one solution to this problem

400-428: A new turbine design known as the "blowdown turbine" or "power-recovery turbine". This design extracts energy from the momentum of the moving exhaust, but does not appreciably increase back-pressure. This means it does not have the undesirable effects of conventional designs when connected to the exhaust of a piston engine, and a number of manufacturers began studying the design. The first aircraft engine to be tested with

440-510: A power-recovery turbine was the Rolls-Royce Crecy . This was used primarily to drive a geared centrifugal supercharger, although it was also coupled to the crankshaft and gave an extra 15 to 35 percent fuel economy. Blowdown turbines became relatively common features in the late- and post-war era, especially for engines designed for long overwater flights. Turbo-compounding was used on several airplane engines after World War II , including

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480-403: A reciprocating engine is proportional to the volume of the combined pistons' displacement. A seal must be made between the sliding piston and the walls of the cylinder so that the high pressure gas above the piston does not leak past it and reduce the efficiency of the engine. This seal is usually provided by one or more piston rings . These are rings made of a hard metal, and are sprung into

520-480: A sequence of strokes that admit and remove gases to and from the cylinder. These operations are repeated cyclically and an engine is said to be 2-stroke , 4-stroke or 6-stroke depending on the number of strokes it takes to complete a cycle. The most common type is 4-stroke, which has following cycles. The reciprocating engine developed in Europe during the 18th century, first as the atmospheric engine then later as

560-457: A single turbocharger that is connected to an electric motor/generator called the MGU-H. The MGU-H uses a turbine to drive a generator, converting waste heat from the exhaust into electrical energy that is either stored in a battery or sent directly to an electric motor in the car's powertrain. Reciprocating engine There may be one or more pistons. Each piston is inside a cylinder , into which

600-586: Is not to be confused with fuel efficiency , since high efficiency often requires a lean fuel-air ratio, and thus lower power density. A modern high-performance car engine makes in excess of 75 kW/L (1.65 hp/in ). Reciprocating engines that are powered by compressed air, steam or other hot gases are still used in some applications such as to drive many modern torpedoes or as pollution-free motive power. Most steam-driven applications use steam turbines , which are more efficient than piston engines. The French-designed FlowAIR vehicles use compressed air stored in

640-412: Is not true of every reciprocating engine), although power and fuel consumption are affected by many factors outside of engine displacement. Reciprocating engines can be characterized by their specific power , which is typically given in kilowatts per litre of engine displacement (in the U.S. also horsepower per cubic inch). The result offers an approximation of the peak power output of an engine. This

680-481: Is owned by Daimler Truck AG . The former off-highway division was sold to MTU Friedrichshafen in 2006 and subsequently purchased by Rolls-Royce in 2014. The ancestor of Detroit Diesel was the Winton Engine Company, founded by Alexander Winton in 1912; Winton Engine began producing diesel engines in fall 1913. After Charles F. Kettering purchased two Winton diesels for his yacht, General Motors acquired

720-394: Is the fictitious pressure which would produce the same amount of net work that was produced during the power stroke cycle. This is shown by: where A p {\displaystyle A_{p}} is the total piston area of the engine, S {\displaystyle S} is the stroke length of the pistons, and V d {\displaystyle V_{d}}

760-459: Is the ratio of the diameter of the piston, or " bore ", to the length of travel within the cylinder, or "stroke". If this is around 1 the engine is said to be "square". If it is greater than 1, i.e. the bore is larger than the stroke, it is "oversquare". If it is less than 1, i.e. the stroke is larger than the bore, it is "undersquare". Cylinders may be aligned in line , in a V configuration , horizontally opposite each other, or radially around

800-425: Is the total displacement volume of the engine. Therefore: Whichever engine with the larger value of MEP produces more net work per cycle and performs more efficiently. In steam engines and internal combustion engines, valves are required to allow the entry and exit of gases at the correct times in the piston's cycle. These are worked by cams, eccentrics or cranks driven by the shaft of the engine. Early designs used

840-423: Is then fed through one or more, increasingly larger bore cylinders successively, to extract power from the steam at increasingly lower pressures. These engines are called compound engines . Aside from looking at the power that the engine can produce, the mean effective pressure (MEP), can also be used in comparing the power output and performance of reciprocating engines of the same size. The mean effective pressure

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880-452: The D slide valve but this has been largely superseded by piston valve or poppet valve designs. In steam engines the point in the piston cycle at which the steam inlet valve closes is called the cutoff and this can often be controlled to adjust the torque supplied by the engine and improve efficiency. In some steam engines, the action of the valves can be replaced by an oscillating cylinder . Internal combustion engines operate through

920-614: The Napier Nomad and the Wright R-3350 . The exhaust restriction imparted by the three blowdown turbines used on the Wright R-3350 is equal to a well-designed jet stack system used on a conventional radial engine , while recovering about 550 hp (410 kW) at METO (maximum continuous except for take-off) power. In the case of the R-3350, maintenance crews sometimes nicknamed the turbine

960-506: The Wright R-3350 Duplex-Cyclone , but electric and hydraulic power recovery systems have been investigated as well. As this recovery process does not increase fuel consumption , it has the effect of reducing the specific fuel consumption , the ratio of fuel use to power. Turbo-compounding was used for commercial airliners and similar long-range, long-endurance roles before the introduction of turbojet engines. Examples using

1000-484: The parts recovery turbine due to its negative effect on engine reliability. Turbo-compound versions of the Napier Deltic , Rolls-Royce Crecy , Rolls-Royce Griffon , and Allison V-1710 were constructed but none was developed beyond the prototype stage. It was realized in many cases the power produced by the simple turbine was approaching that of the enormously complex and maintenance-intensive piston engine to which it

1040-470: The steam engine . These were followed by the Stirling engine and internal combustion engine in the 19th century. Today the most common form of reciprocating engine is the internal combustion engine running on the combustion of petrol , diesel , liquefied petroleum gas (LPG) or compressed natural gas (CNG) and used to power motor vehicles and engine power plants . One notable reciprocating engine from

1080-491: The 20-minute lab tests to verify compliance with the Clean Air Act, but then disable the emissions controls during normal highway cruising, emitting up to three times the maximum allowed NOx pollution. In 2016, Detroit Diesel agreed to pay U.S.$ 28.5 million to resolve violations of the U.S. federal Clean Air Act. The company sold 7,786 heavy-duty diesel engines, which were assembled approximately 80% complete in 2009, including

1120-573: The Duplex-Cyclone include the Douglas DC-7B and Lockheed L-1049 Super Constellation , while other designs did not see production use. Most piston engines produce a hot exhaust that still contains considerable undeveloped energy that could be used for propulsion if extracted. A turbine is often used to extract energy from such a stream of gases. A conventional gas turbine is fed high-pressure, high-velocity air, extracts energy from it, and leaves as

1160-483: The World War II era was the 28-cylinder, 3,500  hp (2,600 kW) Pratt & Whitney R-4360 Wasp Major radial engine. It powered the last generation of large piston-engined planes before jet engines and turboprops took over from 1944 onward. It had a total engine capacity of 71.5 L (4,360 cu in), and a high power-to-weight ratio . The largest reciprocating engine in production at present, but not

1200-454: The company in 1930 along with Electro Motive Company , Winton's primary client. Research initiated by Kettering led to the development and release of the EMD 567 locomotive engine in the late 1930s; a smaller engine using a similar two-stroke design was developed by engineers at GM Research, which led to the first 6-71 , manufactured in 1938. To know the series model one can find out by checking

1240-415: The crankshaft. Opposed-piston engines put two pistons working at opposite ends of the same cylinder and this has been extended into triangular arrangements such as the Napier Deltic . Some designs have set the cylinders in motion around the shaft, such as the rotary engine . In some steam engines, the cylinders may be of varying size with the smallest bore cylinder working the highest pressure steam. This

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1280-506: The cylinder by this stroke . The exception is the Stirling engine , which repeatedly heats and cools the same sealed quantity of gas. The stroke is simply the distance between the TDC and the BDC, or the greatest distance that the piston can travel in one direction. In some designs the piston may be powered in both directions in the cylinder, in which case it is said to be double-acting . In most types,

1320-588: The largest ever built, is the Wärtsilä-Sulzer RTA96-C turbocharged two-stroke diesel engine of 2006 built by Wärtsilä . It is used to power the largest modern container ships such as the Emma Mærsk . It is five stories high (13.5 m or 44 ft), 27 m (89 ft) long, and weighs over 2,300 metric tons (2,535 short tons ; 2,264 long tons ) in its largest 14 cylinders version producing more than 84.42 MW (113,209 bhp). Each cylinder has

1360-406: The largest volume in the cylinder. The piston is returned to the cylinder top (top dead center) (TDC) by a flywheel , the power from other pistons connected to the same shaft or (in a double acting cylinder ) by the same process acting on the other side of the piston. This is where the piston forms the smallest volume in the cylinder. In most types the expanded or " exhausted " gases are removed from

1400-515: The layout of the overall engine. In 1998, the EPA announced fines totaling $ 83.4 million against Detroit Diesel and six other diesel engine manufacturers, the largest fine to date, which evaded testing by shutting down emissions controls during highway driving while appearing to comply with lab testing. The manufacturers also agreed to spend more than $ 1 billion to correct the problem. The trucks used engine ECU software to engage pollution controls during

1440-416: The linear movement of the piston is converted to a rotating movement via a connecting rod and a crankshaft or by a swashplate or other suitable mechanism. A flywheel is often used to ensure smooth rotation or to store energy to carry the engine through an un-powered part of the cycle. The more cylinders a reciprocating engine has, generally, the more vibration-free (smoothly) it can operate. The power of

1480-537: The on-highway and vocational commercial truck markets. Detroit Diesel has built more than 5 million engines since 1938, more than 1 million of which are still in operation worldwide. Detroit Diesel's product line includes engines, axles, transmissions, and a Virtual Technician service. Detroit engines, transmissions, and axles are used in several models of truck manufactured by Daimler Truck North America. Detroit Diesel consists of manufacturing operations of axles, transmissions and diesel engines for on-highway only, which

1520-410: The ones most studied. The quantum versions obey the laws of thermodynamics . In addition, these models can justify the assumptions of endoreversible thermodynamics . A theoretical study has shown that it is possible and practical to build a reciprocating engine that is composed of a single oscillating atom. This is an area for future research and could have applications in nanotechnology . There are

1560-505: Was attached. As a result, turbo-compound aero engines were soon supplanted by turboprop and turbojet engines. Some modern heavy truck diesel manufacturers have incorporated turbo-compounding into their designs. Examples include the Detroit Diesel DD15 and Scania in production from 1991. Starting with the 2014 season, Formula One switched to a new 1.6 liter turbocharged V6 formula that uses turbo-compounding. The engines use

1600-514: Was the introduction of "jet stack" exhaust manifolds. These were simply short sections of metal pipe attached to the exhaust ports, shaped so that they would interact with the airstream to produce a jet of air that produced forward thrust. Another World War II introduction was the use of the Meredith effect to recover heat from the radiator system to provide additional thrust. By the late-war era, turbine development had improved dramatically and led to

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