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40-502: Hermann Oestrich 's team in charge of the development of the BMW 003 engine had moved to the town of Stassfurt , near Magdeburg , in February 1945. An underground production factory was being set up in a salt mine outside town by C.G. Rheinhardt in a desperate attempt to continue engine production in face of the now overwhelming Allied air campaign. This mine is well known historically as it

80-433: A "canular" layout, exiting into the single-stage turbine. Early models were 2.85 m long, 0.9 m in diameter, and weighed 850 kg, while The C models and on were 3.68 m long including the long extension, 0.89 m in diameter, and weighed 940 kg. Later versions were generally similar to the C model, although the inclusion of the afterburner increased length to 5.23 m, and weights varied from 925 to 1,240 kg depending on

120-483: A center-body/bullet/cone to give the nozzle exit area required to set an axial compressor running-line correctly on its map. The first operational German turbojet engines with axial compressors, the Jumo 004 and BMW 003 , needed a different exhaust nozzle areas for running properly at each of the operating regimes: start/idle, climb, high speed, high altitude. A nozzle with a fore/aft-translating "bullet" restrictive body in

160-786: A doctorate at the TH Berlin-Charlottenburg in Berlin in 1937. As part of the new development of jet engines, Oestrich began research in this field. In 1939 he was appointed head of the development of jet engines in the BMW plant in Berlin- Spandau . His developments eventually led to the BMW 003 engine, which was bought in 1946 by the French Air Ministry. In 1943, Oestrich was appointed department director and took over managing gas turbine development. After

200-409: A ring-shaped pattern, which causes less water to strike any one location, and thereby reduces erosion while also making it easier to water larger areas. The shaping of the plug and the nozzle opening allows the angle of the ring to be adjusted. Normally this is shaped so that when the plug is pulled back toward the opening it both partially cuts off the water flow, as well as causing it to spread out to

240-503: A seven-stage axial compressor using aluminum alloy blades attached to an aluminum rotor. The front bearing was held in place by four vanes, with the "left" one as seen from the front containing a power takeoff shaft. One unique feature of the Atar designs was the separate Atar 5000 accessories section, which could be mounted in front of the engine, driven by an extension shaft. The combustion area consisted of twenty steel flame cans arranged in

280-521: A variety of aircraft, including the Étendard and Super Étendard strike aircraft, Mirage III, Mirage 5 and Mirage F1 fighters, the Mirage IV bomber, and a variety of test aircraft. In 1955 the French government started a project to explore flight speeds up to Mach 3.0. SNECMA began studies on an engine to power it, initially consisting of the compressor design of the existing Atar 101, but replacing all of

320-446: A wide base and long tapering forebody. However, the "spike" portion can be cut off with only minor effects on performance, leaving just the base section. This looks very similar to a common drain plug or bung , and leads to widespread use of the term "plug nozzle" for this design as well. The jet-engine plug nozzle has its origins in rocketry but has also been studied over the years, but not used, for supersonic cruise aircraft such as

360-436: A wide range of altitudes. Similar to the garden hose example, plug nozzles use a shaped rocket nozzle with a poppet-shaped plug to allow the pattern of the rocket exhaust to be changed. This is used to adjust for changes in altitude; at lower altitudes the plug is pulled back to cause the exhaust to spread out, while at higher altitudes the lower air pressure will cause this to happen naturally. An alternative construction for

400-750: A wide variety of aircraft. An afterburner was incorporated into the D model to produce the Atar 101F of 37,300 N (8,400 lb f ), while the same addition to the E model produced the 46,110 N (10,370 lb f ) ATAR 101G . These were flight tested on the Dassault Mystère II in August 1954, but they did not see production on this aircraft. Their first success was on the Dassault Super Mystère which first flew under Rolls-Royce Avon power on 2 March 1955, and followed by

440-420: Is a type of nozzle which includes a centerbody or plug around which the working fluid flows. Plug nozzles have applications in aircraft, rockets, and numerous other fluid flow devices. Common garden hose trigger nozzles are a simple example of the plug nozzle and its method of operation. In this example the nozzle consists of a conical or bell shaped opening with a plug on a movable rod positioned in front of

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480-610: The Super Atar design of 85 kN with afterburning. This version also included variable stators , which were in the process of being widely introduced in the industry. However, the project to build the test aircraft, the Griffon III , never went ahead and SNECMA ended development of the Super Atar in 1960. The Atar design was also used for a variety of larger, smaller, and experimental developments. Of particular note are

520-455: The 101, but the new engine included a nine-stage compressor in place of the earlier seven-stage one, and a smaller two-stage turbine to power it. There were many detail improvements as well, including the replacement of the original compressor rotor with a new one made of magnesium alloy. The first Atar 08 B-3 produced 42,000 N (9,400 lb f ) and had a slightly improved overall pressure ratio of 5.5:1. A new and much improved afterburner

560-487: The 101G powered version on 15 May 1956. Production started in 1957 with a contract for 370 aircraft, but this was later cut back to 180 in light of the performance of the Dassault Mirage III which was then undergoing testing. With the Atar 101 now sitting at the low end of the power scale, in 1954 SNECMA started the design of a more radical upgrade, the Atar 08 . Overall design and dimensions were similar to

600-669: The Boeing SST, the proposed General Electric Variable Cycle Engine, with its acoustic plug nozzle, and Concorde. However, it was used for the AGM-28 Hound Dog missile and the Tu-144 airliner. The plug / "external-expanding" nozzle has a central plug and a freely-expanding supersonic jet rather than a diverging cone surface to contain the internal supersonic expansion as in a delaval convergent-divergent nozzle (con-di) nozzle. The Pratt & Whitney J52 aircraft engine used in

640-679: The R.104 Vulcain, a scaled-up Atar, and the much smaller R.105 Vesta. Both engines were developed in parallel to the Atar in the early 1950s in order to fill particular performance niches, the Vulcain for the Mystère IV D, and the Vesta for a variety of designs. None of these entered production, however; the Mystère IV D was cancelled, and the Vesta lost out to the Turboméca Gabizo , which was also abandoned. The original Atar 101 featured

680-765: The Second World War, Oestrich was captured and interrogated for a long time on technical issues. Finally, he was offered a job in the US, which he declined. Together with other former BMW employees, such as Hans-Georg Münzberg , August Wilhelm Quick and Otto David, he accepted a five-year contract with the French Ministry of Aviation. He founded Atar (Atelier technique aéronautique de Rickenbach) in 1946 and headed this development group of 120 employees. He went to Decize in 1946, where he worked for Snecma subsidiary Aeroplanes Voisin. Oestrich and his team worked on

720-527: The US offered him and a hand-selected team jobs in the US, but without their families. Oestrich instead accepted the French invitation, and by September had been set up at the former Dornier factories in Rickenbach in the French Zone, close to the northern border of Switzerland . Here they were soon joined by other former BMW engineers, as well as those from a number of other German firms, bringing

760-481: The earlier experimental models. The first B model passed a 150-hour endurance test in February 1951 at 23,500 N (5,300 lb f ). A flight test followed on 5 December 1951 in the Dassault Ouragan , and starting on 27 March 1952, under the wings of a Gloster Meteor F.4 . After delivering the initial production run of B models, the Atar 101C used an improved compressor and combustion chamber, raising

800-462: The entire team, including protected wages, provisions for their families, few travel restrictions, and the possibility of French citizenship. The contract was signed on 25 April 1946, and the drawings for the ATAR 101 were sent to SNECMA for production. The first engine took some time to assemble. The first parts were available as early as May 1946, but a complete compressor or turbine was not ready until

840-399: The exhaust and afterburner area with one made of titanium that allowed continual operation at Mach 2, up from the C's 1.4. Air cooling was re-introduced for the Atar 9K models, further improving overall performance, and especially fuel economy. With the Atar 8 and 9 series, the long ten years of development had finally resulted in a successful commercial design. Thousands were produced for

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880-576: The further development of the Atar 101 . In 1948 he acquired French citizenship and in 1950 he rose to technical director of Snecma in Villaroche , where the developments of the BMW 003 engine were being monitored. He retired from Snecma in 1960. For his services at Snecma overseeing the development of Snecma Atar turbojet engines, he was awarded Knight of the Legion of Honor in 1962. Plug nozzle#In aircraft and missiles The plug nozzle

920-403: The hose, it flows through the nozzle body to the opening, where it would normally flow straight forward in a stream. Just after leaving the opening it encounters the plug, which deflects the water sideways through an angle. After travelling a short distance the water encounters the outside of the nozzle opening, which deflects it forward again. This two-step process causes the water to be ejected in

960-632: The inside, a feature of the WW II Junkers Jumo 004 axial-flow turbojet, which was known as the Zwiebel (onion) from its shape. The Atar 101E added a "zeroth" compressor stage, raising the overall pressure ratio to 4.8:1 and the thrust to 36,300 N (8,200 lb f ), surpassing the projected thrust of 34.3 kN (7,700 lbf)of the German BMW 018 turbojet still being developed in 1945. Various Atar 101 models were tested on

1000-521: The light alloys with steels in order to handle the increased operating temperatures . This also demanded the use of an air-cooled turbine, similar to the ones from the earliest prototypes. Such an engine, the M.26 , ran in May 1957, giving 47 kN (10,364 lbf) without an afterburner. Further improvements led to the M.28 , which ran in September 1958 at 52 kN (11,466 lbf). This work led to

1040-494: The middle of the next year. The first complete engine finally ran on 26 March 1948. By April 5 it had been brought up to 16,000 N (3,600 lb f ) thrust and was continually improved until it reached 21,600 N (4,900 lb f ) by October. During this time a new turbine made of solid high-temperature steels replaced the earlier air-cooled models, allowing for better aerodynamic shaping and an improved compression ratio. By January 1950 several additional engines had joined

1080-480: The model. The Atar 8 and 9 used a 9-stage compressor similar to the 101, but including a steel first stage in order to improve resistance to foreign object damage . The turbine included two stages. Length and width remained the same as the 101 models, deliberately, but weights further increased up to 1,350 kg for the 9B. Related development Comparable engines Related lists Hermann Oestrich Hermann Oestrich (30 December 1903 – 2 April 1973)

1120-619: The noise. Weight and cooling are typical concerns with aircraft plug nozzles. A plug nozzle design evaluated at the National Gas Turbine Establishment was rejected for the Concorde engine due to the weight penalty from the required variable features and concerns about adequate plug cooling during reheat operation. Plug nozzle model tests have shown reduced noise levels compared to traditional con-di nozzles. Propelling nozzles for subsonic aircraft have used

1160-400: The nozzle. The plug looks similar to a poppet valve . The stem of the valve runs back through the body of the nozzle body to a "trigger", normally a long lever running down the back of the nozzle assembly. A spring keeps the valve pressed against the opening under normal use, thereby providing a failsafe cut-off that stops the flow of water when the nozzle is dropped. When water is supplied to

1200-428: The program, bringing the total running time to over 1,000 hours, and a thrust of 26,490 N (5,960 lb f ), making it among the most powerful engines of the era. The BMW 003 that it was developed from provided only 7,800 N (1,800 lb f ), less than a third of the Atar. The ATAR 101B introduced Nimonic turbine blades and more stator blades as well as a number of changes to fix minor problems seen in

1240-400: The same basic concept is to use two nozzles, one inside the other, and adjust the distance between them. This pattern has the advantage of better control over the exhaust and simpler cooling arrangements. Confusingly, the term "plug nozzle" may also be used to refer to an entirely different class of engine nozzles, the aerospikes. In theory the aerospike should look roughly like a lance , with

Snecma Atar - Misplaced Pages Continue

1280-481: The supersonic AGM-28 Hound Dog missile used a plug nozzle which performed better over the missile's flight envelope than either a convergent or a con-di nozzle. A translating center-body was used on the non-afterburning Kolesov RD-36-51 A engine used for the Tupolev Tu-144 D supersonic airliner. The center-body was perforated and compressed air forced into the exhaust jet through the perforations to attenuate

1320-664: The team to about 200 members. The group was named the Atelier Technique Aéronautique Rickenbach (Rickenbach Aeronautical Technical Workshop in English), or ATAR . They had re-engineered the 003 design as the ATAR 101 (model R.101) by October, and granted a production contract on the proviso that actual production would be carried out in France. In January a further five-year contract was offered to

1360-408: The thrust to 27,400 N (6,200 lb f ). The Atar 101D featured a slightly larger turbine with new high-temperature alloys that allowed the exit temperature to rise to 1,000 °C and the thrust to 29,420 N (6,610 lb f ). The D model also included a new exhaust consisting of a long pipe ending in a nozzle with two "eyelid" shutters in place of the earlier fore/aft moving cone on

1400-489: The war ground to a close, and the US forces cleared out the factory while they waited to turn the area over to the Soviets . Oestrich had by this time moved to Munich for further interrogation, and from there to England at the request of British engine designer Roy Fedden . He had them work on the design of a turboprop engine for a proposed C-54 Skymaster -class four-engine transport. While working on this design, Oestrich

1440-411: The widest possible angle. This can be used for "misting" plants. When the trigger is pushed down further, the plug moves away from the opening, causing less blockage and disruption of the flow, ultimately allowing the water to form back into a stream. Plug nozzles belong to a class of altitude compensating nozzles , much like the aerospike , which, unlike traditional designs, maintains its efficiency at

1480-678: Was a German-French engineer. He was involved in the development of jet engines as an employee of BMW and later of Snecma . Born in Duisburg - Beeckerwerth , Oestrich studied at the Technische Hochschule Hannover and in Berlin . After completing his studies, he first went to the Deutsche Versuchsanstalt für Luftfahrt in 1926, where he remained until he moved to Brandenburgische Motorenwerke in 1935. He became chief engineer of BMW after earning

1520-451: Was also being used for the storage of uranium compounds as part of the Nazi atomic bomb program . The town of Stassfurt surrendered to US forces on 12 April 1945, and Oestrich hid much of the technical data in a local cemetery. The next day a ten-man team made up primarily of engineers from Pratt & Whitney arrived, and he handed the data over to them. Production restarted for US use while

1560-549: Was designed for the engine, resulting in the Atar 09 . It was first tested in January 1957 at 54,900 N (12,300 lb f ), and was soon improved to 58,800 N (13,200 lb f ). A further improved afterburner with an eighteen-flap nozzle in place of the two eyelids of the earlier designs was introduced on the 09C model in December 1959. This version also featured a new starter from Microturbo . The Atar 9D replaced

1600-449: Was secretly approached by French DGER agents with an offer to take up further design of the 003 in France. The French forces had found a number of BMW 003 turbojet engines in their occupation zone after the war, and were interested in setting up a production line. These discussions had not progressed very far when Oestrich was allowed to return to Munich, only to be brought back to England in late August, then returned to Munich again where

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