106-539: The Navistar T444E is a diesel V8 engine manufactured by Navistar International Corporation . In its use in Ford Motor Company trucks, vans, and school buses , it is the first of the Power Stroke family of diesel engines. The T444E was manufactured from 1994 to 2003, replacing the 7.3L IDI V8 designed by International Harvester. As a result of its inability to meet California noise regulations,
212-414: A carcinogen or "probable carcinogen" and is known to increase the risk of heart and respiratory diseases. In principle, a diesel engine does not require any sort of electrical system. However, most modern diesel engines are equipped with an electrical fuel pump, and an electronic engine control unit. However, there is no high-voltage electrical ignition system present in a diesel engine. This eliminates
318-404: A combustion chamber , and accelerate the exhaust rearwards to provide thrust. Different jet engine configurations include the turbojet and turbofan , sometimes with the addition of an afterburner . Those with no rotating turbomachinery include the pulsejet and ramjet . These mechanically simple engines produce no thrust when stationary, so the aircraft must be launched to flying speed using
424-445: A gas engine (using a gaseous fuel like natural gas or liquefied petroleum gas ). 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 so that atomised diesel fuel injected into
530-433: A lifting gas such as helium , hydrogen or hot air , which is less dense than the surrounding air. When the weight of the lifting gas is added to the weight of the aircraft itself, it is same or less than the mass of the air that the craft displaces. Small hot-air balloons, called sky lanterns , were first invented in ancient China prior to the 3rd century BC and used primarily in cultural celebrations, and were only
636-560: A catapult, like the V-1 flying bomb , or a rocket, for example. Other engine types include the motorjet and the dual-cycle Pratt & Whitney J58 . Compared to engines using propellers, jet engines can provide much higher thrust, higher speeds and, above about 40,000 ft (12,000 m), greater efficiency. They are also much more fuel-efficient than rockets . As a consequence nearly all large, high-speed or high-altitude aircraft use jet engines. Some rotorcraft, such as helicopters , have
742-452: A diesel engine drops at lower loads, however, it does not drop quite as fast as the Otto (spark ignition) engine's. Diesel engines are combustion engines and, therefore, emit combustion products in their exhaust gas . Due to incomplete combustion, diesel engine exhaust gases include carbon monoxide , hydrocarbons , particulate matter , and nitrogen oxides pollutants. About 90 per cent of
848-447: A diesel engine, particularly at idling speeds, is sometimes called "diesel clatter". This noise is largely caused by the sudden ignition of the diesel fuel when injected into the combustion chamber, which causes a pressure wave that sounds like knocking. Aircraft An aircraft ( pl. : aircraft) is a vehicle that is able to fly by gaining support from the air . It counters the force of gravity by using either static lift or
954-516: A few degrees releasing the pressure and is controlled by a mechanical governor, consisting of weights rotating at engine speed constrained by springs and a lever. The injectors are held open by the fuel pressure. On high-speed engines the plunger pumps are together in one unit. The length of fuel lines from the pump to each injector is normally the same for each cylinder in order to obtain the same pressure delay. Direct injected diesel engines usually use orifice-type fuel injectors. Electronic control of
1060-407: A finite area, and the net output of work during a cycle is positive. The fuel efficiency of diesel engines is better than most other types of combustion engines, due to their high compression ratio, high air–fuel equivalence ratio (λ) , and the lack of intake air restrictions (i.e. throttle valves). Theoretically, the highest possible efficiency for a diesel engine is 75%. However, in practice
1166-452: A fuel consumption of 519 g·kW ·h . However, despite proving the concept, the engine caused problems, and Diesel could not achieve any substantial progress. Therefore, Krupp considered rescinding the contract they had made with Diesel. Diesel was forced to improve the design of his engine and rushed to construct a third prototype engine. Between 8 November and 20 December 1895, the second prototype had successfully covered over 111 hours on
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#17327805078111272-409: A full set of valves, two-stroke diesel engines have simple intake ports, and exhaust ports (or exhaust valves). When the piston approaches bottom dead centre, both the intake and the exhaust ports are "open", which means that there is atmospheric pressure inside the cylinder. Therefore, some sort of pump is required to blow the air into the cylinder and the combustion gasses into the exhaust. This process
1378-638: A greater wingspan (94m/260 ft) than any current aircraft and a tail height equal to the tallest (Airbus A380-800 at 24.1m/78 ft) — flew only one short hop in the late 1940s and never flew out of ground effect . The largest civilian airplanes, apart from the above-noted An-225 and An-124, are the Airbus Beluga cargo transport derivative of the Airbus A300 jet airliner, the Boeing Dreamlifter cargo transport derivative of
1484-403: A low-pressure loop at the bottom of the diagram. At 1 it is assumed that the exhaust and induction strokes have been completed, and the cylinder is again filled with air. The piston-cylinder system absorbs energy between 1 and 2 – this is the work needed to compress the air in the cylinder, and is provided by mechanical kinetic energy stored in the flywheel of the engine. Work output is done by
1590-674: A marginal case. The forerunner of the fixed-wing aircraft is the kite . Whereas a fixed-wing aircraft relies on its forward speed to create airflow over the wings, a kite is tethered to the ground and relies on the wind blowing over its wings to provide lift. Kites were the first kind of aircraft to fly and were invented in China around 500 BC. Much aerodynamic research was done with kites before test aircraft, wind tunnels , and computer modelling programs became available. The first heavier-than-air craft capable of controlled free-flight were gliders . A glider designed by George Cayley carried out
1696-794: A maximum loaded weight of 550–700 t (1,210,000–1,540,000 lb), it was also the heaviest aircraft built to date. It could cruise at 500 mph (800 km/h; 430 kn). The aircraft was destroyed during the Russo-Ukrainian War . The largest military airplanes are the Ukrainian Antonov An-124 Ruslan (world's second-largest airplane, also used as a civilian transport), and American Lockheed C-5 Galaxy transport, weighing, loaded, over 380 t (840,000 lb). The 8-engine, piston/propeller Hughes H-4 Hercules "Spruce Goose" — an American World War II wooden flying boat transport with
1802-681: A notable exception being the EMD 567 , 645 , and 710 engines, which are all two-stroke. The power output of medium-speed diesel engines can be as high as 21,870 kW, with the effective efficiency being around 47-48% (1982). Most larger medium-speed engines are started with compressed air direct on pistons, using an air distributor, as opposed to a pneumatic starting motor acting on the flywheel, which tends to be used for smaller engines. Medium-speed engines intended for marine applications are usually used to power ( ro-ro ) ferries, passenger ships or small freight ships. Using medium-speed engines reduces
1908-569: A payload of up to 22,050 lb (10,000 kg). The largest aircraft by weight and largest regular fixed-wing aircraft ever built, as of 2016 , was the Antonov An-225 Mriya . That Soviet-built ( Ukrainian SSR ) six-engine transport of the 1980s was 84 m (276 ft) long, with an 88 m (289 ft) wingspan. It holds the world payload record, after transporting 428,834 lb (194,516 kg) of goods, and has flown 100 t (220,000 lb) loads commercially. With
2014-423: A peak power of almost 100 MW each. Diesel engines may be designed with either two-stroke or four-stroke combustion cycles . They were originally used as a more efficient replacement for stationary steam engines . Since the 1910s, they have been used in submarines and ships. Use in locomotives , buses, trucks, heavy equipment , agricultural equipment and electricity generation plants followed later. In
2120-535: A petroleum engine with glow-tube ignition in the early 1890s; he claimed against his own better judgement that his glow-tube ignition engine worked the same way Diesel's engine did. His claims were unfounded and he lost a patent lawsuit against Diesel. Other engines, such as the Akroyd engine and the Brayton engine , also use an operating cycle that is different from the diesel engine cycle. Friedrich Sass says that
2226-415: A poorer power-to-mass ratio than an equivalent petrol engine. The lower engine speeds (RPM) of typical diesel engines results in a lower power output. Also, the mass of a diesel engine is typically higher, since the higher operating pressure inside the combustion chamber increases the internal forces, which requires stronger (and therefore heavier) parts to withstand these forces. The distinctive noise of
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#17327805078112332-588: A powered "tug" aircraft. For a glider to maintain its forward air speed and lift, it must descend in relation to the air (but not necessarily in relation to the ground). Many gliders can "soar", i.e. , gain height from updrafts such as thermal currents. The first practical, controllable example was designed and built by the British scientist and pioneer George Cayley , whom many recognise as the first aeronautical engineer. Common examples of gliders are sailplanes , hang gliders and paragliders . Balloons drift with
2438-491: A powered rotary wing or rotor , where the rotor disc can be angled slightly forward so that a proportion of its lift is directed forwards. The rotor may, like a propeller, be powered by a variety of methods such as a piston engine or turbine. Experiments have also used jet nozzles at the rotor blade tips . Aircraft are designed according to many factors such as customer and manufacturer demand, safety protocols and physical and economic constraints. For many types of aircraft
2544-408: A regular trunk-piston. Two-stroke engines have a limited rotational frequency and their charge exchange is more difficult, which means that they are usually bigger than four-stroke engines and used to directly power a ship's propeller. Four-stroke engines on ships are usually used to power an electric generator. An electric motor powers the propeller. Both types are usually very undersquare , meaning
2650-577: A rigid basket or gondola slung below it to carry its payload. Early aircraft, including airships , often employed flexible doped aircraft fabric covering to give a reasonably smooth aeroshell stretched over a rigid frame. Later aircraft employed semi- monocoque techniques, where the skin of the aircraft is stiff enough to share much of the flight loads. In a true monocoque design there is no internal structure left. The key structural parts of an aircraft depend on what type it is. Lighter-than-air types are characterised by one or more gasbags, typically with
2756-435: A simple mechanical injection system since exact injection timing is not as critical. Most modern automotive engines are DI which have the benefits of greater efficiency and easier starting; however, IDI engines can still be found in the many ATV and small diesel applications. Indirect injected diesel engines use pintle-type fuel injectors. Early diesel engines injected fuel with the assistance of compressed air, which atomised
2862-536: A single orifice injector. The pre-chamber has the disadvantage of lowering efficiency due to increased heat loss to the engine's cooling system, restricting the combustion burn, thus reducing the efficiency by 5–10%. IDI engines are also more difficult to start and usually require the use of glow plugs. IDI engines may be cheaper to build but generally require a higher compression ratio than the DI counterpart. IDI also makes it easier to produce smooth, quieter running engines with
2968-527: A single speed for long periods. Two-stroke engines use a combustion cycle which is completed in two strokes instead of four strokes. Filling the cylinder with air and compressing it takes place in one stroke, and the power and exhaust strokes are combined. The compression in a two-stroke diesel engine is similar to the compression that takes place in a four-stroke diesel engine: As the piston passes through bottom centre and starts upward, compression commences, culminating in fuel injection and ignition. Instead of
3074-426: A small chamber called a swirl chamber, precombustion chamber, pre chamber or ante-chamber, which is connected to the cylinder by a narrow air passage. Generally the goal of the pre chamber is to create increased turbulence for better air / fuel mixing. This system also allows for a smoother, quieter running engine, and because fuel mixing is assisted by turbulence, injector pressures can be lower. Most IDI systems use
3180-530: A source of radio frequency emissions (which can interfere with navigation and communication equipment), which is why only diesel-powered vehicles are allowed in some parts of the American National Radio Quiet Zone . To control the torque output at any given time (i.e. when the driver of a car adjusts the accelerator pedal ), a governor adjusts the amount of fuel injected into the engine. Mechanical governors have been used in
3286-400: A spark plug ( compression ignition rather than spark ignition ). In the diesel engine, only air is initially introduced into the combustion chamber. The air is then compressed with a compression ratio typically between 15:1 and 23:1. This high compression causes the temperature of the air to rise. At about the top of the compression stroke, fuel is injected directly into the compressed air in
Navistar T444E engine - Misplaced Pages Continue
3392-420: A supporting structure of flexible cables or a rigid framework called its hull. Other elements such as engines or a gondola may also be attached to the supporting structure. Heavier-than-air types are characterised by one or more wings and a central fuselage . The fuselage typically also carries a tail or empennage for stability and control, and an undercarriage for takeoff and landing. Engines may be located on
3498-417: A swirl chamber or pre-chamber are called indirect injection (IDI) engines. Most direct injection diesel engines have a combustion cup in the top of the piston where the fuel is sprayed. Many different methods of injection can be used. Usually, an engine with helix-controlled mechanic direct injection has either an inline or a distributor injection pump. For each engine cylinder, the corresponding plunger in
3604-422: A two-stroke ship diesel engine has a single-stage turbocharger with a turbine that has an axial inflow and a radial outflow. In general, there are three types of scavenging possible: Crossflow scavenging is incomplete and limits the stroke, yet some manufacturers used it. Reverse flow scavenging is a very simple way of scavenging, and it was popular amongst manufacturers until the early 1980s. Uniflow scavenging
3710-522: Is a lifting body , which has no wings, though it may have small stabilizing and control surfaces. Wing-in-ground-effect vehicles are generally not considered aircraft. They "fly" efficiently close to the surface of the ground or water, like conventional aircraft during takeoff. An example is the Russian ekranoplan nicknamed the " Caspian Sea Monster ". Man-powered aircraft also rely on ground effect to remain airborne with minimal pilot power, but this
3816-437: Is a powered one. A powered, steerable aerostat is called a dirigible . Sometimes this term is applied only to non-rigid balloons, and sometimes dirigible balloon is regarded as the definition of an airship (which may then be rigid or non-rigid). Non-rigid dirigibles are characterized by a moderately aerodynamic gasbag with stabilizing fins at the back. These soon became known as blimps . During World War II , this shape
3922-423: Is a simplified and idealised representation of the events involved in a diesel engine cycle, arranged to illustrate the similarity with a Carnot cycle . Starting at 1, the piston is at bottom dead centre and both valves are closed at the start of the compression stroke; the cylinder contains air at atmospheric pressure. Between 1 and 2 the air is compressed adiabatically – that is without heat transfer to or from
4028-403: Is approximately 5 MW. Medium-speed engines are used in large electrical generators, railway diesel locomotives , ship propulsion and mechanical drive applications such as large compressors or pumps. Medium speed diesel engines operate on either diesel fuel or heavy fuel oil by direct injection in the same manner as low-speed engines. Usually, they are four-stroke engines with trunk pistons;
4134-429: Is called scavenging . The pressure required is approximately 10-30 kPa. Due to the lack of discrete exhaust and intake strokes, all two-stroke diesel engines use a scavenge blower or some form of compressor to charge the cylinders with air and assist in scavenging. Roots-type superchargers were used for ship engines until the mid-1950s, however since 1955 they have been widely replaced by turbochargers. Usually,
4240-404: Is done on the system to which the engine is connected. During this expansion phase the volume of the gas rises, and its temperature and pressure both fall. At 4 the exhaust valve opens, and the pressure falls abruptly to atmospheric (approximately). This is unresisted expansion and no useful work is done by it. Ideally the adiabatic expansion should continue, extending the line 3–4 to the right until
4346-464: Is more complicated to make but allows the highest fuel efficiency; since the early 1980s, manufacturers such as MAN and Sulzer have switched to this system. It is standard for modern marine two-stroke diesel engines. So-called dual-fuel diesel engines or gas diesel engines burn two different types of fuel simultaneously , for instance, a gaseous fuel and diesel engine fuel. The diesel engine fuel auto-ignites due to compression ignition, and then ignites
Navistar T444E engine - Misplaced Pages Continue
4452-452: Is only because they are so underpowered—in fact, the airframe is capable of flying higher. Rotorcraft, or rotary-wing aircraft, use a spinning rotor with aerofoil cross-section blades (a rotary wing ) to provide lift. Types include helicopters , autogyros , and various hybrids such as gyrodynes and compound rotorcraft. Helicopters have a rotor turned by an engine-driven shaft. The rotor pushes air downward to create lift. By tilting
4558-623: Is stored in tanks, usually in the wings but larger aircraft also have additional fuel tanks in the fuselage . Propeller aircraft use one or more propellers (airscrews) to create thrust in a forward direction. The propeller is usually mounted in front of the power source in tractor configuration but can be mounted behind in pusher configuration . Variations of propeller layout include contra-rotating propellers and ducted fans . Many kinds of power plant have been used to drive propellers. Early airships used man power or steam engines . The more practical internal combustion piston engine
4664-475: Is the Lockheed SR-71 Blackbird , a U.S. reconnaissance jet fixed-wing aircraft, having reached 3,530 km/h (2,193 mph) on 28 July 1976. Gliders are heavier-than-air aircraft that do not employ propulsion once airborne. Take-off may be by launching forward and downward from a high location, or by pulling into the air on a tow-line, either by a ground-based winch or vehicle, or by
4770-461: Is usually high. The diesel engine has the highest thermal efficiency (see engine efficiency ) of any practical internal or external combustion engine due to its very high expansion ratio and inherent lean burn, which enables heat dissipation by excess air. A small efficiency loss is also avoided compared with non-direct-injection gasoline engines, as unburned fuel is not present during valve overlap, and therefore no fuel goes directly from
4876-629: The Bell Boeing V-22 Osprey ), tiltwing , tail-sitter , and coleopter aircraft have their rotors/ propellers horizontal for vertical flight and vertical for forward flight. The smallest aircraft are toys/recreational items, and nano aircraft . The largest aircraft by dimensions and volume (as of 2016) is the 302 ft (92 m) long British Airlander 10 , a hybrid blimp, with helicopter and fixed-wing features, and reportedly capable of speeds up to 90 mph (140 km/h; 78 kn), and an airborne endurance of two weeks with
4982-693: The Boeing 747 jet airliner/transport (the 747-200B was, at its creation in the 1960s, the heaviest aircraft ever built, with a maximum weight of over 400 t (880,000 lb)), and the double-decker Airbus A380 "super-jumbo" jet airliner (the world's largest passenger airliner). The fastest fixed-wing aircraft and fastest glider, is the Space Shuttle , which re-entered the atmosphere at nearly Mach 25 or 17,500 mph (28,200 km/h) The fastest recorded powered aircraft flight and fastest recorded aircraft flight of an air-breathing powered aircraft
5088-637: The Harrier jump jet and Lockheed Martin F-35B take off and land vertically using powered lift and transfer to aerodynamic lift in steady flight. A pure rocket is not usually regarded as an aerodyne because its flight does not depend on interaction with the air at all (and thus can even fly in the vacuum of outer space ); however, many aerodynamic lift vehicles have been powered or assisted by rocket motors. Rocket-powered missiles that obtain aerodynamic lift at very high speed due to airflow over their bodies are
5194-722: The United Kingdom , and the United States for "Method of and Apparatus for Converting Heat into Work". In 1894 and 1895, he filed patents and addenda in various countries for his engine; the first patents were issued in Spain (No. 16,654), France (No. 243,531) and Belgium (No. 113,139) in December 1894, and in Germany (No. 86,633) in 1895 and the United States (No. 608,845) in 1898. Diesel
5300-770: The dynamic lift of an airfoil , or, in a few cases, direct downward thrust from its engines. Common examples of aircraft include airplanes , helicopters , airships (including blimps ), gliders , paramotors , and hot air balloons . The human activity that surrounds aircraft is called aviation . The science of aviation, including designing and building aircraft, is called aeronautics . Crewed aircraft are flown by an onboard pilot , whereas unmanned aerial vehicles may be remotely controlled or self-controlled by onboard computers . Aircraft may be classified by different criteria, such as lift type, aircraft propulsion (if any), usage and others. Flying model craft and stories of manned flight go back many centuries; however,
5406-435: The 1930s, large intercontinental flying boats were also sometimes referred to as "ships of the air" or "flying-ships". — though none had yet been built. The advent of powered balloons, called dirigible balloons, and later of rigid hulls allowing a great increase in size, began to change the way these words were used. Huge powered aerostats, characterized by a rigid outer framework and separate aerodynamic skin surrounding
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#17327805078115512-542: The 1930s, they slowly began to be used in some automobiles . Since the 1970s energy crisis , demand for higher fuel efficiency has resulted in most major automakers, at some point, offering diesel-powered models, even in very small cars. According to Konrad Reif (2012), the EU average for diesel cars at the time accounted for half of newly registered cars. However, air pollution and overall emissions are more difficult to control in diesel engines compared to gasoline engines, and
5618-454: The Carnot cycle. Diesel was also introduced to a fire piston , a traditional fire starter using rapid adiabatic compression principles which Linde had acquired from Southeast Asia . After several years of working on his ideas, Diesel published them in 1893 in the essay Theory and Construction of a Rational Heat Motor . Diesel was heavily criticised for his essay, but only a few found
5724-465: The German engineer Rudolf Diesel , is an internal combustion engine in which ignition of the fuel is caused by the elevated temperature of the air in the cylinder due to mechanical 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
5830-543: The T444E was discontinued midway through the 2003 model year , replaced by the all-new 6.0L VT365 . In total, nearly 2 million 7.3L Power Stroke V8s were manufactured for Ford at Navistar's Indianapolis, Indiana , plant before switching to the 6.0L. The T444E used a 4.11 in × 4.18 in (104.4 mm × 106.2 mm) bore and stroke. Power output was 210 hp (157 kW) at 3000 rpm and 425 lb⋅ft (576 N⋅m) at 1600 rpm for 1994-1997. Power
5936-470: The aircraft's weight. There are two ways to produce dynamic upthrust — aerodynamic lift by having air flowing past an aerofoil (such dynamic interaction of aerofoils with air is the origin of the term "aerodyne"), or powered lift in the form of reactional lift from downward engine thrust . Aerodynamic lift involving wings is the most common, and can be achieved via two methods. Fixed-wing aircraft ( airplanes and gliders ) achieve airflow past
6042-400: The amount of fuel injected into the engine. Due to the amount of air being constant (for a given RPM) while the amount of fuel varies, very high ("lean") air-fuel ratios are used in situations where minimal torque output is required. This differs from a petrol engine, where a throttle is used to also reduce the amount of intake air as part of regulating the engine's torque output. Controlling
6148-501: The autogyro moves forward, air blows upward across the rotor, making it spin. This spinning increases the speed of airflow over the rotor, to provide lift. Rotor kites are unpowered autogyros, which are towed to give them forward speed or tethered to a static anchor in high-wind for kited flight. Compound rotorcraft have wings that provide some or all of the lift in forward flight. They are nowadays classified as powered lift types and not as rotorcraft. Tiltrotor aircraft (such as
6254-470: The bore is smaller than the stroke. Low-speed diesel engines (as used in ships and other applications where overall engine weight is relatively unimportant) often have an effective efficiency of up to 55%. Like medium-speed engines, low-speed engines are started with compressed air, and they use heavy oil as their primary fuel. Four-stroke engines use the combustion cycle described earlier. Most smaller diesels, for vehicular use, for instance, typically use
6360-412: The combustion chamber ignites. With the fuel being injected into the air just before combustion, the dispersion of fuel is uneven; this is called a heterogeneous air-fuel mixture. The torque a diesel engine produces is controlled by manipulating the air-fuel ratio (λ) ; instead of throttling the intake air, the diesel engine relies on altering the amount of fuel that is injected, and thus the air-fuel ratio
6466-448: The combustion chamber, the droplets continue to vaporise from their surfaces and burn, getting smaller, until all the fuel in the droplets has been burnt. Combustion occurs at a substantially constant pressure during the initial part of the power stroke. The start of vaporisation causes a delay before ignition and the characteristic diesel knocking sound as the vapour reaches ignition temperature and causes an abrupt increase in pressure above
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#17327805078116572-418: The combustion chamber. This may be into a (typically toroidal ) void in the top of the piston or a pre-chamber depending upon the design of the engine. The fuel injector ensures that the fuel is broken down into small droplets, and that the fuel is distributed evenly. The heat of the compressed air vaporises fuel from the surface of the droplets. The vapour is then ignited by the heat from the compressed air in
6678-425: The compressed gas. Combustion and heating occur between 2 and 3. In this interval the pressure remains constant since the piston descends, and the volume increases; the temperature rises as a consequence of the energy of combustion. At 3 fuel injection and combustion are complete, and the cylinder contains gas at a higher temperature than at 2. Between 3 and 4 this hot gas expands, again approximately adiabatically. Work
6784-452: The compression ratio in a spark-ignition engine where fuel and air are mixed before entry to the cylinder is limited by the need to prevent pre-ignition , which would cause engine damage. Since only air is compressed in a diesel engine, and fuel is not introduced into the cylinder until shortly before top dead centre ( TDC ), premature detonation is not a problem and compression ratios are much higher. The pressure–volume diagram (pV) diagram
6890-473: The compression required for his cycle: By June 1893, Diesel had realised his original cycle would not work, and he adopted the constant pressure cycle. Diesel describes the cycle in his 1895 patent application. Notice that there is no longer a mention of compression temperatures exceeding the temperature of combustion. Now it is simply stated that the compression must be sufficient to trigger ignition. In 1892, Diesel received patents in Germany , Switzerland ,
6996-416: The concept of air-blast injection from George B. Brayton , albeit that Diesel substantially improved the system. On 17 February 1894, the redesigned engine ran for 88 revolutions – one minute; with this news, Maschinenfabrik Augsburg's stock rose by 30%, indicative of the tremendous anticipated demands for a more efficient engine. On 26 June 1895, the engine achieved an effective efficiency of 16.6% and had
7102-424: The cost of smaller ships and increases their transport capacity. In addition to that, a single ship can use two smaller engines instead of one big engine, which increases the ship's safety. Low-speed diesel engines are usually very large in size and mostly used to power ships . There are two different types of low-speed engines that are commonly used: Two-stroke engines with a crosshead, and four-stroke engines with
7208-435: The design process is regulated by national airworthiness authorities. The key parts of an aircraft are generally divided into three categories: The approach to structural design varies widely between different types of aircraft. Some, such as paragliders, comprise only flexible materials that act in tension and rely on aerodynamic pressure to hold their shape. A balloon similarly relies on internal gas pressure, but may have
7314-616: The diesel engine is Diesel's "very own work" and that any "Diesel myth" is " falsification of history ". Diesel sought out firms and factories that would build his engine. With the help of Moritz Schröter and Max Gutermuth [ de ] , he succeeded in convincing both Krupp in Essen and the Maschinenfabrik Augsburg . Contracts were signed in April 1893, and in early summer 1893, Diesel's first prototype engine
7420-417: The efficiency is much lower, with efficiencies of up to 43% for passenger car engines, up to 45% for large truck and bus engines, and up to 55% for large two-stroke marine engines. The average efficiency over a motor vehicle driving cycle is lower than the diesel engine's peak efficiency (for example, a 37% average efficiency for an engine with a peak efficiency of 44%). That is because the fuel efficiency of
7526-408: The environment – by the rising piston. (This is only approximately true since there will be some heat exchange with the cylinder walls .) During this compression, the volume is reduced, the pressure and temperature both rise. At or slightly before 2 (TDC) fuel is injected and burns in the compressed hot air. Chemical energy is released and this constitutes an injection of thermal energy (heat) into
7632-477: The first manned ascent — and safe descent — in modern times took place by larger hot-air balloons developed in the 18th century. Each of the two World Wars led to great technical advances. Consequently, the history of aircraft can be divided into five eras: Lighter-than-air aircraft or aerostats use buoyancy to float in the air in much the same way that ships float on the water. They are characterized by one or more large cells or canopies, filled with
7738-532: The first true manned, controlled flight in 1853. The first powered and controllable fixed-wing aircraft (the airplane or aeroplane) was invented by Wilbur and Orville Wright . Besides the method of propulsion (if any), fixed-wing aircraft are in general characterized by their wing configuration . The most important wing characteristics are: A variable geometry aircraft can change its wing configuration during flight. A flying wing has no fuselage, though it may have small blisters or pods. The opposite of this
7844-463: The four-stroke cycle. This is due to several factors, such as the two-stroke design's narrow powerband which is not particularly suitable for automotive use and the necessity for complicated and expensive built-in lubrication systems and scavenging measures. The cost effectiveness (and proportion of added weight) of these technologies has less of an impact on larger, more expensive engines, while engines intended for shipping or stationary use can be run at
7950-616: The fuel and forced it into the engine through a nozzle (a similar principle to an aerosol spray). The nozzle opening was closed by a pin valve actuated by the camshaft . Although the engine was also required to drive an air compressor used for air-blast injection, the efficiency was nonetheless better than other combustion engines of the time. However the system was heavy and it was slow to react to changing torque demands, making it unsuitable for road vehicles. A unit injector system, also known as "Pumpe-Düse" ( pump-nozzle in German) combines
8056-700: The fuel injection transformed the direct injection engine by allowing much greater control over the combustion. Common rail (CR) direct injection systems do not have the fuel metering, pressure-raising and delivery functions in a single unit, as in the case of a Bosch distributor-type pump, for example. A high-pressure pump supplies the CR. The requirements of each cylinder injector are supplied from this common high pressure reservoir of fuel. An Electronic Diesel Control (EDC) controls both rail pressure and injections depending on engine operating conditions. The injectors of older CR systems have solenoid -driven plungers for lifting
8162-405: The fuel pump measures out the correct amount of fuel and determines the timing of each injection. These engines use injectors that are very precise spring-loaded valves that open and close at a specific fuel pressure. Separate high-pressure fuel lines connect the fuel pump with each cylinder. Fuel volume for each single combustion is controlled by a slanted groove in the plunger which rotates only
8268-418: The fuselage or wings. On a fixed-wing aircraft the wings are rigidly attached to the fuselage, while on a rotorcraft the wings are attached to a rotating vertical shaft. Smaller designs sometimes use flexible materials for part or all of the structure, held in place either by a rigid frame or by air pressure. The fixed parts of the structure comprise the airframe . The source of motive power for an aircraft
8374-514: The gas bags, were produced, the Zeppelins being the largest and most famous. There were still no fixed-wing aircraft or non-rigid balloons large enough to be called airships, so "airship" came to be synonymous with these aircraft. Then several accidents, such as the Hindenburg disaster in 1937, led to the demise of these airships. Nowadays a "balloon" is an unpowered aerostat and an "airship"
8480-461: The gaseous fuel. Such engines do not require any type of spark ignition and operate similar to regular diesel engines. The fuel is injected at high pressure into either the combustion chamber , "swirl chamber" or "pre-chamber," unlike petrol engines where the fuel is often added in the inlet manifold or carburetor . Engines where the fuel is injected into the main combustion chamber are called direct injection (DI) engines, while those which use
8586-419: The injection needle, whilst newer CR injectors use plungers driven by piezoelectric actuators that have less moving mass and therefore allow even more injections in a very short period of time. Early common rail system were controlled by mechanical means. The injection pressure of modern CR systems ranges from 140 MPa to 270 MPa. An indirect diesel injection system (IDI) engine delivers fuel into
8692-553: The injector and fuel pump into a single component, which is positioned above each cylinder. This eliminates the high-pressure fuel lines and achieves a more consistent injection. Under full load, the injection pressure can reach up to 220 MPa. Unit injectors are operated by a cam and the quantity of fuel injected is controlled either mechanically (by a rack or lever) or electronically. Due to increased performance requirements, unit injectors have been largely replaced by common rail injection systems. The average diesel engine has
8798-561: The intake/injection to the exhaust. Low-speed diesel engines (as used in ships and other applications where overall engine weight is relatively unimportant) can reach effective efficiencies of up to 55%. The combined cycle gas turbine (Brayton and Rankine cycle) is a combustion engine that is more efficient than a diesel engine, but due to its mass and dimensions, is unsuitable for many vehicles, including watercraft and some aircraft . The world's largest diesel engines put in service are 14-cylinder, two-stroke marine diesel engines; they produce
8904-476: The mistake that he made; his rational heat motor was supposed to utilise a constant temperature cycle (with isothermal compression) that would require a much higher level of compression than that needed for compression ignition. Diesel's idea was to compress the air so tightly that the temperature of the air would exceed that of combustion. However, such an engine could never perform any usable work. In his 1892 US patent (granted in 1895) #542846, Diesel describes
9010-534: The past, however electronic governors are more common on modern engines. Mechanical governors are usually driven by the engine's accessory belt or a gear-drive system and use a combination of springs and weights to control fuel delivery relative to both load and speed. Electronically governed engines use an electronic control unit (ECU) or electronic control module (ECM) to control the fuel delivery. The ECM/ECU uses various sensors (such as engine speed signal, intake manifold pressure and fuel temperature) to determine
9116-480: The piston (not shown on the P-V indicator diagram). When combustion is complete the combustion gases expand as the piston descends further; the high pressure in the cylinder drives the piston downward, supplying power to the crankshaft. As well as the high level of compression allowing combustion to take place without a separate ignition system, a high compression ratio greatly increases the engine's efficiency. Increasing
9222-403: The piston-cylinder combination between 2 and 4. The difference between these two increments of work is the indicated work output per cycle, and is represented by the area enclosed by the pV loop. The adiabatic expansion is in a higher pressure range than that of the compression because the gas in the cylinder is hotter during expansion than during compression. It is for this reason that the loop has
9328-417: The pollutants can be removed from the exhaust gas using exhaust gas treatment technology. Road vehicle diesel engines have no sulfur dioxide emissions, because motor vehicle diesel fuel has been sulfur-free since 2003. Helmut Tschöke argues that particulate matter emitted from motor vehicles has negative impacts on human health. The particulate matter in diesel exhaust emissions is sometimes classified as
9434-408: The pressure falls to that of the surrounding air, but the loss of efficiency caused by this unresisted expansion is justified by the practical difficulties involved in recovering it (the engine would have to be much larger). After the opening of the exhaust valve, the exhaust stroke follows, but this (and the following induction stroke) are not shown on the diagram. If shown, they would be represented by
9540-411: The rotor forward, the downward flow is tilted backward, producing thrust for forward flight. Some helicopters have more than one rotor and a few have rotors turned by gas jets at the tips. Some have a tail rotor to counteract the rotation of the main rotor, and to aid directional control. Autogyros have unpowered rotors, with a separate power plant to provide thrust. The rotor is tilted backward. As
9646-436: The second type of aircraft to fly, the first being kites , which were also first invented in ancient China over two thousand years ago (see Han Dynasty ). A balloon was originally any aerostat, while the term airship was used for large, powered aircraft designs — usually fixed-wing. In 1919, Frederick Handley Page was reported as referring to "ships of the air," with smaller passenger types as "Air yachts." In
9752-544: The test bench. In the January 1896 report, this was considered a success. In February 1896, Diesel considered supercharging the third prototype. Imanuel Lauster , who was ordered to draw the third prototype " Motor 250/400 ", had finished the drawings by 30 April 1896. During summer that year the engine was built, it was completed on 6 October 1896. Tests were conducted until early 1897. First public tests began on 1 February 1897. Moritz Schröter 's test on 17 February 1897
9858-530: The tether or kite line ; they rely on virtual or real wind blowing over and under them to generate lift and drag. Kytoons are balloon-kite hybrids that are shaped and tethered to obtain kiting deflections, and can be lighter-than-air, neutrally buoyant, or heavier-than-air. Powered aircraft have one or more onboard sources of mechanical power, typically aircraft engines although rubber and manpower have also been used. Most aircraft engines are either lightweight reciprocating engines or gas turbines . Engine fuel
9964-890: The timing of the start of injection of fuel into the cylinder is similar to controlling the ignition timing in a petrol engine. It is therefore a key factor in controlling the power output, fuel consumption and exhaust emissions. There are several different ways of categorising diesel engines, as outlined in the following sections. Günter Mau categorises diesel engines by their rotational speeds into three groups: High-speed engines are used to power trucks (lorries), buses , tractors , cars , yachts , compressors , pumps and small electrical generators . As of 2018, most high-speed engines have direct injection . Many modern engines, particularly in on-highway applications, have common rail direct injection . On bigger ships, high-speed diesel engines are often used for powering electric generators. The highest power output of high-speed diesel engines
10070-657: The use of diesel auto engines in the U.S. is now largely relegated to larger on-road and off-road vehicles . Though aviation has traditionally avoided using diesel engines, aircraft diesel engines have become increasingly available in the 21st century. Since the late 1990s, for various reasons—including the diesel's inherent advantages over gasoline engines, but also for recent issues peculiar to aviation—development and production of diesel engines for aircraft has surged, with over 5,000 such engines delivered worldwide between 2002 and 2018, particularly for light airplanes and unmanned aerial vehicles . In 1878, Rudolf Diesel , who
10176-460: The wind, though normally the pilot can control the altitude, either by heating the air or by releasing ballast, giving some directional control (since the wind direction changes with altitude). A wing-shaped hybrid balloon can glide directionally when rising or falling; but a spherically shaped balloon does not have such directional control. Kites are aircraft that are tethered to the ground or other object (fixed or mobile) that maintains tension in
10282-431: The wing. A flexible wing is a wing made of fabric or thin sheet material, often stretched over a rigid frame, similar to the flight membranes on many flying and gliding animals . A kite is tethered to the ground and relies on the speed of the wind over its wings, which may be flexible or rigid, fixed, or rotary. With powered lift, the aircraft directs its engine thrust vertically downward. V/STOL aircraft, such as
10388-402: The wings by having the entire aircraft moving forward through the air, while rotorcraft ( helicopters and autogyros ) do so by having mobile, elongated wings spinning rapidly around a mast in an assembly known as the rotor . As aerofoils, there must be air flowing over the wing to create pressure difference between above and below, thus generating upward lift over the entire wetted area of
10494-532: Was a student at the "Polytechnikum" in Munich , attended the lectures of Carl von Linde . Linde explained that steam engines are capable of converting just 6–10% of the heat energy into work, but that the Carnot cycle allows conversion of much more of the heat energy into work by means of isothermal change in condition. According to Diesel, this ignited the idea of creating a highly efficient engine that could work on
10600-488: Was attacked and criticised over several years. Critics claimed that Diesel never invented a new motor and that the invention of the diesel engine is fraud. Otto Köhler and Emil Capitaine [ de ] were two of the most prominent critics of Diesel's time. Köhler had published an essay in 1887, in which he describes an engine similar to the engine Diesel describes in his 1893 essay. Köhler figured that such an engine could not perform any work. Emil Capitaine had built
10706-477: Was built in Augsburg . On 10 August 1893, the first ignition took place, the fuel used was petrol. In winter 1893/1894, Diesel redesigned the existing engine, and by 18 January 1894, his mechanics had converted it into the second prototype. During January that year, an air-blast injection system was added to the engine's cylinder head and tested. Friedrich Sass argues that, it can be presumed that Diesel copied
10812-434: Was increased in 1998 to 235 hp (175 kW) at 2600 rpm and 500 lb⋅ft (678 N⋅m) of torque at 1600 rpm. In 2000, power was once again upped to 250 hp (186 kW) at 2700 rpm with automatic transmission and 275 hp (205 kW) with manual transmission , and 525 lb⋅ft (712 N⋅m) of torque at 1600 rpm. Applications: Diesel engine The diesel engine , named after
10918-675: Was of the NASA X-43 A Pegasus , a scramjet -powered, hypersonic , lifting body experimental research aircraft, at Mach 9.68 or 6,755 mph (10,870 km/h) on 16 November 2004. Prior to the X-43A, the fastest recorded powered airplane flight, and still the record for the fastest manned powered airplane, was the North American X-15 , rocket-powered airplane at Mach 6.7 or 7,274 km/h (4,520 mph) on 3 October 1967. The fastest manned, air-breathing powered airplane
11024-424: Was the main test of Diesel's engine. The engine was rated 13.1 kW with a specific fuel consumption of 324 g·kW ·h , resulting in an effective efficiency of 26.2%. By 1898, Diesel had become a millionaire. The characteristics of a diesel engine are The diesel internal combustion engine differs from the gasoline powered Otto cycle by using highly compressed hot air to ignite the fuel rather than using
11130-490: Was used for virtually all fixed-wing aircraft until World War II and is still used in many smaller aircraft. Some types use turbine engines to drive a propeller in the form of a turboprop or propfan . Human-powered flight has been achieved, but has not become a practical means of transport. Unmanned aircraft and models have also used power sources such as electric motors and rubber bands. Jet aircraft use airbreathing jet engines , which take in air, burn fuel with it in
11236-439: Was widely adopted for tethered balloons ; in windy weather, this both reduces the strain on the tether and stabilizes the balloon. The nickname blimp was adopted along with the shape. In modern times, any small dirigible or airship is called a blimp, though a blimp may be unpowered as well as powered. Heavier-than-air aircraft or aerodynes are denser than air and thus must find some way to obtain enough lift that can overcome
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