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82-516: The Bell XP-83 (later redesignated XF-83 ) was a United States prototype jet escort fighter designed by Bell Aircraft during World War II . It first flew in 1945. As with most early first generation jet fighters , the design was hampered by a relative lack of power. With the rapid advancements in jet technology post-WWII, the XP-83 was soon eclipsed by more advanced designs and it never entered production. The early jet fighters consumed fuel at

164-477: A centrifugal compressor with a radial inflow turbine, a design that proved to be impractical and as a result, despite much effort, was never put into production. By comparison, Whittle's centrifugal flow engines, in both straight-through and reverse flow configuration (developed further by Rolls Royce), powered all Allied World War II jets and the majority of immediate post-war fighters. They were built under licence in numerous countries including Australia, France and

246-455: A combustion chamber of unknown endurance to flight readiness, I came upon the idea of separating the turbine problem from the combustion chamber problem by using hydrogen fuel. As a physicist, I knew of course that the diffusion and combustion speed of gaseous hydrogen was substantially greater than that of petrol." A study of the model's airflow resulted in several improvements over a two-month period. Encouraged by these findings, Ohain produced

328-639: A fuel system to enable it to run self-contained on liquid fuel, which was achieved in September 1937. With the heavy backing of Heinkel, Ohain's jet engine was the first to power an aircraft, the Heinkel He 178 aircraft in 1939, which was followed by Whittle's engine within the Gloster E.28/39 in 1941. Turbojet powered fighter aircraft from both Germany and Britain entered operational use virtually simultaneously in July 1944:

410-510: A highly flammable fabric surface. During the 1920s and 1930s a number of approaches were tried. A variety of motorjet , turboprop , pulsejet and rocket powered aircraft were designed. Rocket-engine research was being carried out in Germany and the first aircraft to fly under rocket power was the Lippisch Ente , in 1928. The Ente had previously been flown as a glider. The next year, in 1929,

492-553: A jet fighter on 26 July 1944, the day before the British Gloster Meteor entered operational service. The Me 262 had first flown on April 18, 1941, but mass production did not start until early 1944, with the first squadrons operational that year, too late for any effect on the outcome of the World War II . While only around 15 Meteors were operational during WW2, up to 1,400 Me 262 were produced, with 300 entering combat. Only

574-516: A jet-powered aircraft in 1910, the Coandă-1910 . However, to support this claim, he had to make substantial alterations to the drawings which he used to support his subsequently debunked claims. In fact the ducted-fan engine backfired, setting the aircraft on fire before any flights were ever made, and it lacked nearly all of the features necessary for a jet engine - including a lack of fuel injection, and any concern about hot jet efflux being directed at

656-444: A local garage, Bartles and Becker. There he met an automotive mechanic, Max Hahn, and eventually arranged for him to build a demonstration model of his engine for 500  ℛ︁ℳ︁ . The completed model was larger in diameter than Whittle's fully working engine of 1937, although much shorter. Ohain took the model to the university for testing but ran into problems with combustion of the petrol fuel, which took place mostly after

738-509: A lower exhaust speed than turbojets, and are mostly used for high sonic, transonic, and low supersonic speeds. High bypass turbofans are relatively efficient, and are used by subsonic aircraft such as airliners. Jet aircraft fly considerably differently than propeller aircraft . One difference is that jet engines respond relatively slowly. This complicates takeoff and landing maneuvers. In particular, during takeoff, propeller aircraft engines blow air over their wings and that gives more lift and

820-662: A meeting between his engineers and Ohain, during which he argued that the current "garage engine" would never work, but that the concept upon which it was based was sound. The engineers were convinced, and in April Ohain and Hahn began working for Heinkel at the Marienehe airfield outside Rostock , in Warnemuende. Working with Engineer Gundermann and Hahn in Special Development, von Ohain states: "Under pressure of aiming to bring

902-549: A new "pet project" of his own, eventually becoming the Heinkel HeS 011 . Although this was the first of Schelp's "Class II" engines to start working well, production had still not started when the war ended. Work continued on the HeS 8 for some time, but it was eventually abandoned in the spring of 1943. Part of the challenge for von Ohain was his approach to designing a practical turbojet that could be developed. His primary design comprised

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984-466: A new prototype that would run on hydrogen gas supplied by an external pressurised source. The resulting Heinkel-Strahltriebwerk 1 (HeS 1), German for Heinkel Jet Engine 1, was built by hand-picking some of the best machinists in the company, much to the chagrin of the shop-floor supervisors. Hahn, meanwhile, worked on the combustion problem, an area in which he had some experience. The engine was extremely simple, made largely of sheet metal. Construction, by

1066-492: A patent of an idea ... We thought that it was not seriously being worked on." In February 1937, the turbine section was running on a test stand. According to von Ohain, "We were now working on a machine capable of powering an aircraft, the forerunner of the He-S3B. I had intended to put the combustion chamber between the compressor and the turbine, as we had done with the hydrogen unit, but Hahn suggested putting it ahead of them, which

1148-440: A patent on his version of a jet engine, Process and Apparatus for Producing Airstreams for Propelling Airplanes . Unlike Frank Whittle 's Power Jets WU design with its axial flow turbine, Ohain used a radial in-flow turbine to go with a centrifugal compressor , placing them back-to-back with an annular combustion space wrapped around the rotor. While working at the university, Ohain used to take his sports car to be serviced at

1230-481: A prodigious rate which severely limited their range and endurance . In March 1944, the United States Army Air Forces requested Bell to design a fighter with increased endurance and formally awarded a contract for two prototypes on 31 July 1944. Bell had been working on its "Model 40" interceptor design since 1943. It was redesigned as a long-range escort fighter while retaining the general layout of

1312-583: A radial inflow turbine. Ultimately, this configuration had too many shortcomings to be put into production; however, aided by the enormous resources of the Heinkel Aircraft Company, a developed version was sufficient to power the He-178, and on 27 August 1939 von Ohain entered history as the designer of the world's first gas turbine to power an aircraft. Von Ohain stayed with centrifugal designs, contributing his research to Heinkel's other projects such as

1394-462: A second one was nearing completion at about the same time as a new test airframe, the Heinkel He 178 , which first flew on 27 August 1939, the first jet-powered aircraft to fly by test pilot Erich Warsitz . Heinkel had applied, May 31, 1939, for a patent: US2256198 Espacenet - Original document , an 'Aircraft power plant', inventor Max Hahn. First application for this patent in Germany was May, 1938. Work started immediately on larger versions, first

1476-413: A shorter takeoff. These differences caught out some early BOAC Comet pilots. In aircraft overall propulsive efficiency η {\displaystyle \eta } is the efficiency, in percent, with which the energy contained in a vehicle's propellant is converted into useful energy, to replace losses due to air drag , gravity, and acceleration. It can also be stated as the proportion of

1558-434: A small and low bubble style canopy. The armament was to be six 0.5 in (12.7 mm) machine guns in the nose. Early wind tunnel reports had pinpointed directional instability but the "fix" of a larger tail would not be ready in time for flight testing. The first prototype was flown on 25 February 1945, by Bell's chief test pilot, Jack Woolams . He found it to have satisfactory flight characteristics, although it

1640-422: A speed that is the same as, or nearly the same as, the vehicle velocity. The exact formula for air-breathing engines as given in the literature, is where c is the exhaust speed, and v is the speed of the aircraft. For a long range jet operating in the stratosphere , the speed of sound is constant, hence flying at fixed angle of attack and constant Mach number causes the aircraft to climb, without changing

1722-483: A two-flow, dual entrance flow radial flow compressor that looked monstrous from an engine point of view. Its flow reversal looked to us to be an undesirable thing, but it turned out that it wasn't so bad after although it gave some minor instability problems ... Our patent claims had to be narrowed in comparison to Whittle's because Whittle showed certain things." He then somewhat understandably justified their knowledge of Whittle's work by saying: "We felt that it looked like

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1804-495: A version of the Whittle engine built by General Electric . The Meteor was the first production jet, with the first orders for production examples being made on 8 August 1941, the prototype first flying on 5 March 1943 and the first production aircraft flying on 12 January 1944, while the first orders for production Me 262 aircraft were not issued until 25 May 1943, and the first production Me 262 did not fly until 28 March 1944 despite

1886-559: Is known as the Breguet range equation after the French aviation pioneer Louis Charles Breguet . Hans von Ohain Hans Joachim Pabst von Ohain (14 December 1911 – 13 March 1998) was a German physicist, engineer, and the designer of the first aircraft to use a turbojet engine. Together with Frank Whittle and Anselm Franz , he has been described as the co-inventor of

1968-650: Is the X-15 at Mach 6.85. The Space Shuttle , while far faster than the X-43 or X-15, was not regarded as an aircraft during ascent as it was carried ballistically by rocket thrust, rather than the air. During re-entry it was classed (like a glider) as an unpowered aircraft. The first flight was in 1981. The Bell 533 (1964), Lockheed XH-51 (1965), and Sikorsky S-69 (1977-1981) are examples of compound helicopter designs where jet exhaust added to forward thrust. The Hiller YH-32 Hornet and Fairey Ultra-light Helicopter were among

2050-427: Is the cycle efficiency and η p {\displaystyle \eta _{p}} is the propulsive efficiency. The cycle efficiency, in percent, is the proportion of energy that can be derived from the energy source that is converted to mechanical energy by the engine . For jet aircraft the propulsive efficiency (essentially energy efficiency ) is highest when the engine emits an exhaust jet at

2132-565: Is therefore an important consideration. Jet aircraft are usually designed using the Whitcomb area rule , which says that the total area of cross-section of the aircraft at any point along the aircraft from the nose must be approximately the same as that of a Sears-Haack body . A shape with that property minimises the production of shockwaves which would waste energy. There are several types of engine which operate by expelling hot gas: The different types are used for different purposes. Rockets are

2214-568: The BMW 003 . By early 1942 the HeS 8, officially the 109-001 (HeS 001), was still not progressing well. Meanwhile, Müller's HeS 30, officially the 109-006 (HeS 006), was developing much more quickly. Both engines were still some time from being ready for production, however, while the 003 and 004 appeared to be ready to go. In early 1942 the director of jet development at the RLM, Helmut Schelp , refused further funding for both designs, and ordered Heinkel to work on

2296-647: The Boeing 707 to enter service in 1958 and thus to dominate the market for civilian airliners. The underslung engines were found to be advantageous in the event of a propellant leak, and so the 707 looked rather different from the Comet: the 707 has a shape that is effectively the same as that of contemporary aircraft, with marked commonality still evident today for example with the 737 (fuselage) and A340 (single deck, swept wing, four below-wing engines). Turbofan aircraft with far greater fuel efficiency began entering service in

2378-606: The Charles Stark Draper Prize for their work on turbojet engines. Ohain was elected a member of the U.S. National Academy of Engineering (NAE). Ohain was awarded the Ludwig-Prandtl-Ring from the Deutsche Gesellschaft für Luft- und Raumfahrt (German Society for Aeronautics and Astronautics) for "outstanding contribution in the field of aerospace engineering" in 1992. In 1982, Ohain was inducted into

2460-714: The International Air & Space Hall of Fame at the San Diego Air & Space Museum . In 1990, Ohain was inducted into the National Aviation Hall of Fame . Ohain died in Melbourne, Florida, in 1998, aged 86. He was survived by his wife and four children. One of his sons, Christopher von Ohain, joined the United States Marine Corps (USMC). Christopher’s son, Hans Christopher von Ohain, also joined

2542-557: The Me 262 on July 26 and the Gloster Meteor on July 27 of 1944. The Me 262 was the first operational fighter jet and saw flight combat with hundreds of machines, while the few dozen Meteors saw limited action. Although Von Ohain and Whittle both knew about axial flow compressors, they remained dedicated to improving centrifugal compressor engines to power respectively the Heinkel He 178 and

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2624-766: The Nakajima J9Y Kikka , a modified, and slightly smaller version of the Me 262 that had folding wings. By the end of 1945, the US had introduced their first jet fighter, the Lockheed P-80 Shooting Star into service and the UK its second fighter design, the de Havilland Vampire . The US introduced the North American B-45 Tornado , their first jet bomber, into service in 1948. It was capable of carrying nuclear weapons, but

2706-502: The Opel RAK.1 became the first purpose-built rocket aircraft to fly. The turbojet was invented in the 1930s, independently by Frank Whittle and later Hans von Ohain . The first turbojet aircraft to fly was the Heinkel He 178 , on August 27, 1939 in Rostock (Germany), powered by von Ohain's design. This was largely a proof of concept, as the problem of " creep " (metal fatigue caused by

2788-455: The P-59 Airacomet . The two General Electric J33 -GE-5 turbojet engines were located in each wing root which left the large and bulky fuselage free for fuel tanks and armament. The fuselage was an all-metal semimonocoque capable of carrying 1,150 gal (4,350 L) of fuel. In addition, two 250 gal (950 L) drop tanks could be carried. The cabin was pressurized and used

2870-897: The United States Air Force Exceptional Civilian Service Award, Systems Command Award for Exceptional Civilian Service, the Eugene M. Zuckert Management Award, the Air Force Special Achievement Award, and just before he retired, the Citation of Honor. In 1984–85, Ohain served as the Charles A. Lindbergh Chair in Aerospace History , a competitive senior fellowship at the National Air and Space Museum . In 1991 Ohain and Whittle were jointly awarded

2952-488: The speed of sound . Jet aircraft generally cruise most efficiently at about Mach 0.8 (981 km/h (610 mph)) and at altitudes around 10,000–15,000 m (33,000–49,000 ft) or more. The idea of the jet engine was not new, but the technical problems involved did not begin to be solved until the 1930s. Frank Whittle , an English inventor and RAF officer, began development of a viable jet engine in 1928, and Hans von Ohain in Germany began work independently in

3034-541: The 1950s and 1960s, and became the most commonly used type of jet. The Tu-144 supersonic transport was the fastest commercial jet aircraft at Mach 2.35 (2,503 km/h (1,555 mph)). It went into service in 1975, but was withdrawn from commercial service shortly afterwards. The Mach 2 Concorde entered service in 1976 and flew for 27 years. The fastest military jet aircraft was the SR-71 Blackbird at Mach 3.35 (3,661 km/h (2,275 mph)). Most people use

3116-574: The Gloster E.28/39 until the end of the Second World War. Axial flow compressor jet engines were instead developed in parallel by Anselm Franz (Junkers) and Hermann Oestrich (BMW) to design the similar Jumo 004 and BMW 003 engines, designs that were eventually adopted by most manufacturers by the 1950s. After the war the two men met, became friends and received the Charles Stark Draper Prize for Engineering "for their independent development of

3198-452: The HeS 6 which was simply a larger HeS 3b, and then on a new design known as the HeS 8 which once again re-arranged the overall layout. The compressor and turbine were connected with a large-diameter drum long-enough to fit an annular combustion chamber between them. It was intended to install the engine on the Heinkel He 280 fighter , but the airframe development progressed much more smoothly than

3280-520: The Me 262 program having started earlier than that of the Meteor, as Projekt 1065, with initial plans drawn up by Waldemar Voigt's design team in April 1939. The Messerschmitt Me 262 was the first operational jet fighter , manufactured by Germany during World War II and entering service on 19 April 1944 with Erprobungskommando 262 at Lechfeld just south of Augsburg. An Me 262 scored the first combat victory for

3362-493: The RAF engineer ran the world's first jet engine on the 12th of April 1937), nevertheless Ohain had been given a copy of Whittle's patents by his lawyer, while his own patent application being prepared and before he had begun construction of an engine. In his biography, Ohain frankly critiqued Whittle's design: "When I saw Whittle's patent I was almost convinced that it had something to do with boundary layer suction combinations. It had

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3444-662: The US and were copied by the Russians and Chinese to power the MiG-15 and MiG-17. Whittle's basic reverse flow design remains the most common gas turbine configuration in production today with over 80,000 built in the form of the Allison (RR) 250/300 and Pratt & Whitney PT6 series of engines. However, in his invention of HE S011 , von Ohain introduced a standard concept which combined axial and radial designs for most business jets today, along with turboprops and helicopters. In 1947, Ohain

3526-456: The airflow through the engine created a stable vortex that acted as the compressor and turbine. This interest in mass-flow led Ohain to research magnetohydrodynamics (MHD) for power generation, noting that the hot gases from a coal-fired plant could be used to extract power from their speed when exiting the combustion chamber, remaining hot enough to then power a conventional steam turbine. Thus an MHD generator could extract further power from

3608-500: The bent and folded sheet metal, and a re-arrangement of the layout to reduce the cross-sectional area of the engine by placing the annular combustor in an extended gap between the compressor and turbine. The original turbine was too small to work efficiently. In the beginning of 1939, the He-S3A was fitted into the He 178 airframe for a standing display at Roggentin on 3 July 1939. Yet this turbine

3690-473: The blacksmith in his village, started late in the summer of 1936 and was completed in March 1937. Two weeks later the engine was running on hydrogen, but the high temperature exhaust led to considerable "burning" of the metal. The tests were otherwise successful, and in September the combustor was replaced and the engine was run on gasoline for the first time. Running on gasoline caused the combustor to clog up. Although

3772-507: The cancellation of the XP-83 project in 1947. Data from War Planes of the Second World War General characteristics Performance Armament Related development Related lists Jet aircraft Whereas the engines in propeller-powered aircraft generally achieve their maximum efficiency at much lower speeds and altitudes, jet engines achieve maximum efficiency at speeds close to or even well above

3854-438: The coal, and lead to greater efficiencies. Unfortunately this design has proven difficult to build due to a lack of proper materials, namely high-temperature non-magnetic materials that are also able to withstand the chemically active exhaust. Ohain also investigated other power related concepts. He also invented the idea of the "jet wing", in which air from the compressor of a jet engine is bled off to large "augmented" vents in

3936-607: The combined centrifugal/axial HeS8 and 011, but ultimately none of his designs was put into production. Other competing German designers at Junkers and BMW, following the axial design layout, saw their engines brought into production, although they never solved some of the basic power and durability problems. Von Ohain nevertheless started the world's first jet engine industry in his homeland of Germany, with many prototypes and series productions built until 1945 . Von Ohain, having entered turbojet design some time later than Whittle, began working on his first turbojet engine designs during

4018-643: The conclusion that a constant work process, i.e. constant compression, combustion, expansion, would have great advantages. Thus I chose a quite simple engine, a radial compressor with a radial turbine." However, the model he and Max Hahn built and tested in the courtyard of the Institute showed the combustion chamber needed further development. As a consequence, Pohl and von Ohain decided to approach Heinkel as someone who "doesn't back away from new ideas". In February 1936, Pohl wrote to Ernst Heinkel , telling him about Ohain's design and its possibilities. Heinkel arranged

4100-492: The early 1930s. In August 1939 the turbojet powered Heinkel He 178 , the world's first jet aircraft, made its first flight. A wide range of different types of jet aircraft exist, both for civilian and military purposes. After the first instance of powered flight, a large number of jet engine designs were suggested. René Lorin , Morize, Harris proposed systems for creating a jet efflux. After other jet engines had been run, Romanian inventor Henri Coandă claimed to have built

4182-451: The early 1960s he did a fair amount of work on the design of gas core reactor rockets which would retain the nuclear fuel while allowing the working mass to be used as exhaust. The engineering needed for this role was also used for a variety of other "down to earth" purposes, including centrifuges and pumps. Ohain would later use the basic mass-flow techniques of these designs to create a fascinating jet engine with no moving parts, in which

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4264-453: The engine was never intended to be a flight-quality design, it proved beyond a doubt that the basic concept was workable, and Ohain had at last caught up with Whittle. With vastly more funding and industry support, Ohain would soon overtake Whittle and forge ahead. It has often been claimed that Ohain was unaware of Whittle's work. While in a very strict sense this may be true (in that he was unaware of Whittle's experiments at Lutterworth where

4346-431: The engine, and had to be used in gliding tests while work on the engine continued. A flight-quality HeS 8 was installed in late March 1941, followed by the first flight on 2 April. Three days later the aircraft was demonstrated for a party of Nazi and RLM officials, all of whom were impressed. Full development funds soon followed. By this point there were a number of turbojet developments taking place in Germany. Heinkel

4428-525: The entire tube. The final result of the changes was the He-S3B." A new design, the HeS 3b was proposed, which lengthened the combustor by placing the forward part of it in front of the compressor outer rim. While not as small as the original HeS 3 design, the 3b was nevertheless fairly compact. The 3b first ran in July 1939 (some references say in May), and was air-tested under the Heinkel He 118 dive bomber prototype. The original 3b engine soon burned out, but

4510-428: The fall of 1933 when I was in my seventh semester at Göttingen University. I didn't know that many people before me had the same thought." Unlike Whittle, von Ohain had the significant advantage of being supported by an aircraft manufacturer, Heinkel, who funded his work. When in 1935 von Ohain designed his overall engine layout, he based it for compactness on a centrifugal impeller (centrifugal or radial compressor) and

4592-458: The first commercial jet service, from London to Johannesburg , in 1952 with the de Havilland Comet jetliner . This highly innovative aircraft travelled far faster and higher than propeller aircraft, was much quieter, smoother, and had stylish blended wings containing hidden jet engines. However, due to a design defect, and use of aluminium alloys, the aircraft suffered catastrophic metal fatigue which led to several crashes, which gave time for

4674-485: The high temperatures within the engine) had not been solved, and the engine quickly burned out. Von Ohain's design, an axial-flow engine, as opposed to Whittle's centrifugal flow engine, was eventually adopted by most manufacturers by the 1950s. The first flight of a jet-propelled aircraft to come to public attention was the Italian Caproni Campini N.1 motorjet prototype which flew on August 27, 1940. It

4756-476: The major centers for aeronautical research, with Ohain having attended lectures by Ludwig Prandtl . In 1933, while still a student, he conceived what he called "an engine that did not require a propeller ". After receiving his PhD in 1935, Ohain became the junior assistant of Robert Wichard Pohl , then director of the Physical Institute of the university. In 1936, while working for Pohl, Ohain registered

4838-476: The many helicopters where the rotors were driven by tip jets . Jet-powered wingsuits exist – powered by model aircraft jet engines – but of short duration and needing to be launched at height. Because of the way they work, the typical exhaust speed of jet engines is transonic or faster, therefore most jet aircraft need to fly at high speeds, either supersonic or speeds just below the speed of sound (" transonic ") so as to achieve efficient flight. Aerodynamics

4920-576: The mechanical energy actually used to propel the aircraft. It is always less than 100% because of kinetic energy loss to the exhaust, and less-than-ideal efficiency of the propulsive mechanism, whether a propeller , a jet exhaust, or a fan. In addition, propulsive efficiency is greatly dependent on air density and airspeed. Mathematically, it is represented as η = η c η p {\displaystyle \eta =\eta _{c}\eta _{p}} where η c {\displaystyle \eta _{c}}

5002-594: The mind of Paul Bevilaqua , one of his students at WP-AFB , from math to engineering, which later enabled Bevilaqua to invent the Rolls-Royce LiftSystem for the JSF F35B STOVL : "in school I learned how to move the pieces, and Hans taught me how to play chess". Ohain also showed Bevilaqua "what those TS-diagrams actually mean". Ohain retired from Wright-Patterson in 1979 and took up an associate professor position teaching propulsion and thermodynamics at

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5084-641: The nearby University of Dayton , spending winter sessions from 1981 to 1983 teaching the same subjects at the University of Florida . Ohain continued at the University of Dayton until 1992, when concerns about his health prompted a move with his wife, Hanny, to Melbourne, Florida . During his career, Ohain won many engineering and management awards, including (among others) the American Institute of Aeronautics and Astronautics (AIAA) Goddard Astronautics Award,

5166-399: The oldest type, and are mainly used when extremely high speeds are needed, or operation at extremely high altitudes where there is insufficient air to operate a jet engine. Due to the extreme, typically hypersonic , exhaust velocity and the necessity of oxidiser being carried on board, they consume propellant extremely quickly, making them impractical for routine transportation. Turbojets are

5248-549: The rocket-propelled Messerschmitt Me 163 Komet was a faster operational aircraft during the war. Around this time, mid 1944, the United Kingdom's Meteor was being used for defence of the UK against the V-1 flying bomb  – the V-1 itself a pulsejet -powered aircraft and direct ancestor of the cruise missile  – and then ground-attack operations over Europe in the last months of

5330-454: The same period that Whittle was building his WU engine in Britain. Their turbojet designs have been said by some to be an example of simultaneous invention. However, von Ohain explains in his biography that, in 1935, while his own patent was being prepared (and before he had begun construction of an engine), his lawyer gave him a copy of Whittle's patent, which he read and critiqued. As a result, he

5412-409: The second oldest type; they have a high, usually supersonic, exhaust speed and low frontal cross-section, and so are best suited to high-speed, usually supersonic, flight. Although once widely used, they are relatively inefficient compared to turboprop and turbofans for subsonic flight. The last major aircraft to use turbojets were Concorde and Tu-144 supersonic transports . Low bypass turbofans have

5494-484: The term 'jet aircraft' to denote gas turbine based airbreathing jet engines , but rockets and scramjets are both also propelled by jet propulsion. Cruise missiles are single-use unmanned jet aircraft, powered predominantly by ramjets or turbojets or sometimes turbofans, but they will often have a rocket propulsion system for initial propulsion. The fastest airbreathing jet aircraft is the unmanned X-43 scramjet at around Mach 9–10. The fastest manned (rocket) aircraft

5576-443: The turbine, sending flames shooting out from the exhaust duct. The lack of combustion before the turbine contributed to the engine being unable to run without the assistance of the electric motor which subsequently overheated. According to von Ohain, "My interest in jet engines began in about 1933. I found that the elegance of flying was spoiled by the enormous vibrations and noise from the piston engine/propeller combination. I came to

5658-536: The turbojet engine. However, the historical timelines show that von Ohain was still a university student when, in January 1930, Whittle filed his first patent for a turbojet engine and successfully tested his first engine in April 1937, some 6 months before von Ohain. Additionally, prior to designing his engine and filing his own patent in 1935, von Ohain had read and critiqued Whittle's patents. Von Ohain stated in his biography that "My interest in jet propulsion began in

5740-555: The turbojet engine." Born in Dessau , Germany, Ohain finished high school in 1930 at the Arndt-Gymnasium in Dahlem and earned a PhD in physics in 1935 at the University of Göttingen , with his thesis entitled An Interference Light Relay for White Light on an optical microphone to record sound directly to film, which led to his first patent. The University of Göttingen was then one of

5822-578: The value of the local speed of sound. In this case: V = a M {\displaystyle V=aM} where M {\displaystyle M} is the cruise Mach number and a {\displaystyle a} the local speed of sound. The range equation can be shown to be: R = a M c T C L C D l n W 1 W 2 {\displaystyle R={\frac {aM}{c_{T}}}{\frac {C_{L}}{C_{D}}}ln{\frac {W_{1}}{W_{2}}}} which

5904-481: The war. In 1944 Germany introduced the Arado Ar 234 jet reconnaissance and bomber aircraft into service, though chiefly used in the former role, with the Heinkel He 162 Spatz single-jet light fighter appearing at the end of 1944. USSR tested its own Bereznyak-Isayev BI-1 in 1942, but the project was scrapped by leader Joseph Stalin in 1945. The Imperial Japanese Navy also developed jet aircraft in 1945, including

5986-528: The wings to provide lift for VTOL aircraft. A small amount of high-pressure air is blown into a venturi , which in turn sucks a much larger volume of air along with it, thus leading to "thrust augmentation". The concept was used in the Rockwell XFV-12 experimental aircraft, although the market interest in VTOL aircraft was short-lived. He participated in several other patents. Ohain was the influence in shifting

6068-459: Was an excellent idea." The He-S3 turbine was test flown by Erich Warsitz and Walter Künzel in a Heinkel He 118 , providing additional throttled thrust to the conventional engine. While work on the HeS 1 continued, the Pohl-Ohain team had already moved on to the design of a flight-quality engine, the HeS 3 . The major differences were the use of machined compressor and turbine stages, replacing

6150-795: Was brought to the United States by Operation Paperclip and went to work for the United States Air Force at Wright-Patterson Air Force Base . In 1956 he was made the Director of the Air Force Aeronautical Research Laboratory and by 1975 he was the Chief Scientist of the Aero Propulsion Laboratory there. During his work at Wright-Patterson, Ohain continued his own personal work on various topics. In

6232-442: Was forced to modify his own application so as not to infringe on Whittle's design. The core of Ohain's first jet engine, the Heinkel HeS 1 , which he described as his "hydrogen test engine," was run "in March or early April" according to Ohain (although Ernst Heinkel's diaries record it as September 1937). Work on the hydrogen test engine continued, but the engine required modifications to fix overtemperature problems and to fit

6314-538: Was so impressed by the concept that he arranged the transfer to the project of Adolph Müller from Junkers , who was developing an axial compressor -powered design, renamed as the Heinkel HeS 30 . Müller left Junkers after they purchased the Junkers Motoren company, who had their own project under way, which by this time was known as the Junkers Jumo 004 . Meanwhile, BMW was making good progress with its own design,

6396-401: Was still not powerful enough for flight. According to von Ohain, "We experimented with various combinations to modify the compressor diffuser and turbine nozzle vanes to increase thrust sufficiently to qualify the aircraft for the first flight demonstration. We found that a small diffuser behind the engine with a collar and splitter to divert flows functioned better than a high speed flow through

6478-697: Was the first jet aircraft recognised by the Fédération Aéronautique Internationale (at the time the German He 178 program was still kept secret). Campini began development of the motorjet in 1932; it differed from a true turbojet in that the turbine was driven by a piston engine, rather than combustion of the turbine gases - which was a much more complex solution. The British experimental Gloster E.28/39 first flew on May 15, 1941, powered by Sir Frank Whittle 's turbojet. The United States Bell XP-59A flew on October 1, 1942, using two examples of

6560-623: Was under-powered. The expected instability was confirmed – spins were avoided (until a larger tail fin was installed). The second prototype did incorporate a modified tail and an aileron boost system. One unusual characteristic was extremely high landing speeds, due to factors including the XP-83's lack of drag brakes – in addition to the sleek aerodynamics and relatively high minimum thrust settings common to early jet aircraft, and necessary to prevent unintended flame-outs. This meant that test pilots were forced to fly "stabilized approaches" (i.e. very long and flat landing approaches). The first prototype

6642-622: Was used for reconnaissance over Korea. On November 8, 1950, during the Korean War , United States Air Force Lt. Russell J. Brown, flying in an F-80 , intercepted two North Korean MiG-15s near the Yalu River and shot them down in the first jet-to-jet dogfight in history. The UK put the English Electric Canberra into service in 1951 as a light bomber . It was designed to fly higher and faster than any interceptor . BOAC operated

6724-401: Was used in 1946 as a ramjet test-bed with an engineer's station located in the fuselage behind the pilot. On 14 September 1946, one of the ramjets caught fire forcing pilot, "Slick" Goodlin and engineer Charles Fay , to bail out. The second prototype flew on 19 October and was later scrapped in 1947. Apart from range, the XP-83 was inferior to the Lockheed P-80 Shooting Star and this led to

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