Junkers Jumo 004
The Junkers Jumo 004, was the world's first production turbojet engine in operational use, the first successful axial compressor turbojet engine. Some 8,000 units were manufactured by Junkers in Germany late in World War II, powering the Messerschmitt Me 262 fighter and the Arado Ar 234 reconnaissance/bomber, along with prototypes, including the Horten Ho 229. Variants and copies of the engine were produced in Eastern Europe and the USSR for several years following the end of WWII; the feasibility of jet propulsion had been demonstrated in Germany in early 1937 by Hans von Ohain working with the Heinkel company. Most of the Reich Air Ministry remained uninterested, but Helmut Schelp and Hans Mauch saw the potential of the concept and encouraged Germany's aero engine manufacturers to begin their own programmes of jet engine development; the companies remained little new development was carried out. In 1939 Schelp and Mauch visited the companies to check up on progress. Otto Mader, head of the Junkers Motorenwerke division of the large Junkers aviation firm, stated that if the concept was useful, he had no one to work on it.
Schelp responded by stating that Dr Anselm Franz in charge of Junkers' turbo- and supercharger development, would be perfect for the job. Franz started his development team that year, the project was given the RLM designation 109-004. Franz opted for a design, at once conservative and revolutionary, his design differed from von Ohain's in that he utilised a new type of compressor which allowed a continuous, straight flow of air through the engine developed by the Aerodynamische Versuchsanstalt at Göttingen. The axial-flow compressor not only had excellent performance, about 78% efficient in "real world" conditions, but it had a smaller cross-section, important for high-speed aircraft. Dr. Bruno Bruckman's old assistant on the jet engine program, Dr. Österich, took over for him in Berlin, selected the axial flow design, due to its smaller diameter. On the other hand, he aimed to produce an engine, far below its theoretical potential, in the interests of expediting development and simplifying production.
One major decision was to opt for a simple combustion area using six "flame cans", instead of the more efficient single annular can. For the same reasons, he collaborated on the development of the engine's turbine with Allgemeine Elektrizitäts-Gesellschaft in Berlin, instead of building development engines, opted to begin work on the prototype of an engine that could be put straight into production. Franz's conservative approach came under question from the RLM, but was vindicated when given the developmental problems that it was to face, the 004 entered production and service well ahead of the BMW 003, its more technologically advanced but lower thrust competitor. At Kolbermoor, location of the Heinkel-Hirth engine works, the Fedden Mission, led by Sir Roy Fedden, found jet engine manufacturing was simpler and required lower-skill labor and less sophisticated tooling than piston engine production. Fedden himself criticized the attachment of the 004's compressor casing, in two halves, bolted to the half-sections of the stator assemblies.
The first prototype 004A, constructed to run on diesel fuel, was first tested in October 1940, though without an exhaust nozzle. It was benchtested at the end of January 1941 to a top thrust of 430 kgf, work continued to increase the output, the RLM contract having set a minimum of 600 kgf thrust. Vibration problems with the compressor stators cantilevered from the outside, delayed the program at this point. Max Bentele, as an Air Ministry consulting engineer with a background in turbocharger vibrations, assisted in solving the problem; the original aluminium stators were replaced with steel ones in which configuration the engine developed 5.9 kN in August, passed a 10-hour endurance run at 9.8 kN in December. The first flight test took place on March 15, 1942, when a 004A was carried aloft by a Messerschmitt Bf 110 to run up the engine in flight; the 004 used an eight-stage axial-flow compressor, with six axial combustion chambers, a one-stage turbine with hollow blades. On July 18, one of the prototype Messerschmitt Me 262s flew for the first time under jet power from its 004 engines, the 004 was ordered into production by the RLM to the extent of 80 engines.
The initial 004A engines built to power the Me 262 prototypes had been built without restrictions on materials, they used scarce raw materials such as nickel and molybdenum in quantities which were unacceptable in production. Franz realized that the Jumo 004 would have to be redesigned to incorporate a minimum of these strategic materials, this was accomplished. All the hot metal parts, including the combustion chamber, were changed to mild steel protected by an aluminum coating, the hollow turbine blades were produced from folded and welded Cromadur alloy developed by Krupp, cooled by compressed air "bled" from the compressor; the engine's operational lifespan was shortened. Production engines had a cast magnesium casin
A reciprocating engine often known as a piston engine, is a heat engine that uses one or more reciprocating pistons to convert pressure into a rotating motion. This article describes the common features of all types; the main types are: the internal combustion engine, used extensively in motor vehicles. Internal combustion engines are further classified in two ways: either a spark-ignition engine, where the spark plug initiates the combustion. There may be one or more pistons; each piston is inside a cylinder, into which a gas is introduced, either under pressure, or heated inside the cylinder either by ignition of a fuel air mixture or by contact with a hot heat exchanger in the cylinder. The hot gases expand; this position is known as the Bottom Dead Center, or where the piston forms the largest volume in the cylinder. The piston is returned to the cylinder top by a flywheel, the power from other pistons connected to the same shaft or by the same process acting on the other side of the piston.
This is. In most types the expanded or "exhausted" gases are removed from the cylinder by this stroke; the exception is the Stirling engine, which heats and cools the same sealed quantity of gas. The stroke is 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, 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 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 the more vibration-free it can operate. The power of 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 provided by one or more piston rings. These are rings made of a hard metal, are sprung into a circular groove in the piston head; the rings fit in the groove and press against the cylinder wall to form a seal, more 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 measured in cubic centimetres or litres or. For example, for internal combustion engines and two-cylinder designs are common in smaller vehicles such as motorcycles, while automobiles have between four and eight, locomotives, ships may have a dozen cylinders or more. Cylinder capacities may range from 10 cm³ 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, the volume when the piston is at the top of its stroke.
The bore/stroke ratio 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 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 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 eccentrics or cranks driven by the shaft of the engine. Early designs used the D slide valve but this has been 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 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 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. In some steam engines, the cylinders may be of varying size with the smallest bore cylinder working the highest pressure steam; this is fed through one or more larger bore cylinders successively, to extract power from the steam at lower pressures. These engines are called Compound engines. Aside from loo
The Tumansky R-29 is a Soviet turbojet aircraft engine, developed in the early 1970s. It is described as being in the "third generation" of Soviet gas turbine engines which are characterized by high thrust-to-weight ratios and the use of turbine air cooling. R-29-300 Original variant. Used in the MiG-23MF and related variants. R-29B-300 Simplified variant of the engine intended for the MiG-27. R-29PN Advanced variant. R-29BS-300 Variant with modified gearbox. Used in several export variants of the Sukhoi Su-17. IAR 95 Mikoyan-Gurevich MiG-23 Mikoyan MiG-27 Shenyang J-13 Sukhoi Su-22 Data from Gunston Type: Turbojet Length: 4,991 mm Diameter: 968 mm Dry weight: 1,760 kg Compressor: Two-spool Five-stage low pressure, six-stage high pressure Combustors: Annular Turbine: Two-stage high pressure, single-stage low pressure Maximum thrust: 78,48 kN dry 112,81 kN with afterburner Overall pressure ratio: 12.9:1 Air mass flow: 105 kg/s Turbine inlet temperature: 1,083 °C Specific fuel consumption: =95,8 kg/ at maximum military power 183.5 kg/ with afterburner Power-to-weight ratio: Comparable engines Lyulka AL-21Related lists List of aircraft engines R-29 on leteckemotory.cz
The Tumansky R-25 is a turbojet engine, seen as the ultimate development of Tumansky R-11. It was designed under the leadership of Sergei Alekseevich Gavrilov; the Tumansky R-25 was designed as a replacement for Tumansky R-13 in MiG-21 fighters. R-25 is a two-spool axial-flow turbojet featuring a new compressor with increased overall pressure ratio and airflow, variable two-stage afterburner, greater use of titanium; the R-25 jet engine's specialty was the addition of a second fuel pump in the afterburning stage. Activating the ЧР booster feature allows the engine to develop 96.8 kilonewtons of thrust under 4,000 metres of altitude. The limit of operation is 1 minute for dogfight practice and 3 minutes for an actual wartime emergency, as further use causes the engine to overheat and explode. Use of CSR requires engine take-out inspection upon landing and every minute of its use counts as one full hour of engine runtime on the logbook; this further shortens the limited cycle time of Soviet made engines between industrial-level overhauls and adds great cost, but the extreme thrust of CSR allowed the MiG-21bis to reach a better than 1:1 thrust-to-weight ratio for dogfight and theoretically outclimb the F-16.
The R-25 engine was used on the Sukhoi Su-15bis. A total of 3,200 R-25 were built between 1971 and 1975; the engine was built under license by HAL in India for its fleet of MiG-21bis. Type: Afterburning turbojet Length: 4,615 mm Diameter: 1,191 mm Dry weight: 1,212 kg Compressor: Two-spool axial compressor Maximum thrust: 55 kilonewtons military power 68.5 kilonewtons with afterburner 96.8 kilonewtons for 3 minutes with boosted afterburner Overall pressure ratio: 9.5:1 Turbine inlet temperature: 1,040 °C Specific fuel consumption: 93 kg/ at idle 98 kg/ at maximum military power 229 kg/ with afterburner Thrust-to-weight ratio: 56.5 N/kg, 79.9 N/kg with boosted afterburner Related development Tumansky R-11 Tumansky R-13 Related lists List of aircraft engines R-25 on LeteckeMotory.cz
The Sino-Soviet split was the breaking of political relations between the People's Republic of China and the Union of Soviet Socialist Republics, caused by doctrinal divergences that arose from their different interpretations and practical applications of Marxism–Leninism, as influenced by their respective geopolitics during the Cold War. In the late 1950s and the early 1960s, Sino-Soviet debates about the interpretation of Orthodox Marxism became specific disputes about the Soviet Union's policies of national de-Stalinization and international peaceful coexistence with the Western world. Against that political background, the international relations of the PRC featured official belligerence towards the West, an initial, public rejection of the Soviet policy of peaceful coexistence between the Eastern bloc and the Western bloc, which Mao Zedong said was Marxist revisionism by the Russian communists. In 1956, Nikita Khrushchev denounced Stalin and Stalinism in the speech On the Cult of Personality and its Consequences and began the de-Stalinization of the USSR, whilst the PRC and the USSR progressively diverged in their interpretations of and practical applications of Marxism.
Among the Eastern Bloc countries, the Sino-Soviet split was a question of who would lead the revolution for world communism: China or Russia, to whom would the vanguard parties of the world turn for political advice, financial aid, military assistance? In that vein, the USSR and the PRC competed for the ideological leadership of world communism, through the communist parties native to the countries in their spheres of influence. In the Western world, the Sino–Soviet split transformed the geopolitics of the bi-polar cold war into a tri-polar cold war. Moreover, the Sino-Soviet split voided the Western political perception that "monolithic communism", the Eastern Bloc, was a unitary actor in geopolitics during the 1947–1950 period in the Vietnam War, which led to U. S. military intervention to the First Indochina War. The ideological Sino-Soviet split facilitated the Marxist–Leninist Realpolitik by which Mao established the tri-polar geopolitics of the late-period Cold War. In the course of the Second World War, the Communist Party of China and the nationalist Kuomintang party set aside their civil war in order to fight and expel Imperial Japan from China.
To that end, the leader of the USSR, Joseph Stalin, ordered Mao Zedong, leader of the CPC, to co-operate with Generalissimo Chiang Kai-shek, leader of the KMT, in fighting the Second Sino-Japanese War. Following the surrender of Japan, the CPC and the KMT resumed their civil war, from which the CPC emerged victorious. At war's end, Stalin advised Mao to not seize political power at that time, instead, to collaborate with Chiang due to the USSR–KMT Treaty of Friendship and Alliance. Yet, three months after the Japanese surrender, in November 1945, when Chiang opposed the annexation of Tannu Uriankhai to the USSR, Stalin broke the treaty requiring the Red Army's withdrawal from Manchuria and ordered General Rodion Malinovsky to give to the Chinese communists the spoils of war captured from the Imperial Japanese Army. In the post-war 1945–1950 period, the United States had financed the KMT, his nationalist political party, the National Revolutionary Army, his armed forces in the civil war. S. sent General George Marshall to broker peace between the communist and anti-communist belligerents.
In the concluding, three-year period of the Chinese Civil War, between the KMT and the CPC, the Chinese Communist Revolution defeated and expelled the KMT from mainland China. The KMT retreated to Taiwan, where Gen. Chiang Kai-shek established the Republic of China, in 1950; as a theoretician of Communism seeking to realise a socialist state in China, Mao developed and adapted the urban ideology of Orthodox Marxism for practical application to the agrarian conditions of pre-industrial China and the Chinese people. Mao's Sinification of Marx, Socialism with Chinese characteristics, established political pragmatism as the first priority for realising the accelerated modernisation of a country and a people. In 1947, whilst fighting the Chinese Communist Revolution against the KMT nationalists, Mao despatched the American journalist Anna Louise Strong to the West, bearing political documents explaining China's socialist future, asked that she "show them to Party leaders in the United States and Europe", for their better understanding of the Chinese Communist Revolution, but that it was not "necessary to take them to Moscow".
Mao trusted Strong because of her positive reportage about him, as a theoretician of Communism, in the article "The Thought of Mao Tse-Tung", about t
The Tumansky RD-9 was an early Soviet turbojet engine, not based on pre-existing German or British designs. The AM-5 was available in 1952 and completed testing in 1953. AM-5 engine is notable for making the first Soviet supersonic interceptor possible, the MiG-19 and the first all-weather area interceptor, the Yak-25; when Sergei Tumansky replaced Alexander Mikulin as the OKB-24's chief designer in 1956, the engine was renamed RD-9. The engine was built under license in China as the WP-6. RD-9A RD-9B Used in the East German civilian jetliner project Baade 152 in 1958 and 1959, replaced when Pirna 014 engines became available. RD-9AK Non-afterburning versions for the Yak-25 and Yak-26. RD-9AF-300 Afterburning version for the Yak-27 and Yak-28. RD-9AF2-300 Afterburning version for the Yak-27 and Yak-28. RD-9B Afterburning version for early MiG-19s. RD-9BK Version for Lavochkin La-17M. RD-9BF-811 Afterburning version for MiG-19s. RD-9V Afterburning version used in the Ilyushin Il-40P. WP-6 Chinese built version for the Shenyang J-6 and Nanchang Q-5.
NK-TJ North Korean version built for MiG-19 and Shenyang J-6 Data from Type: Afterburning turbojet Length: 5,560 mm Diameter: 670 mm Dry weight: 725 kg Compressor: Single-spool 9-stage Axial compressor Maximum thrust: 3,000 kgf military power, 3,750 kgf with afterburner Turbine inlet temperature: 860 ° C Specific fuel consumption: 104 kg/ military power, 169 kg/ with afterburner Thrust-to-weight ratio: 5.2:1 Related lists List of aircraft engines RD-9B page on LeteckeMotory.cz