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25-515: SEPR may refer to: Société d'Etudes pour la Propulsion par Réaction , French rocket-engine manufacturer Sepracor Sepracor, Inc. ( former NASDAQ: SEPR ), pharmaceutical company United Socialist Party of Russia , Russian political party (abbreviation of Russian name) Evangelical Seminary of Puerto Rico , Protestant seminary in Puerto Rico (abbreviation of Spanish name) Topics referred to by

50-505: A Gloster Meteor F.4 (RA491). The ATAR 101 was steadily developed with improvements to materials, aerodynamic design, compressors, combustion chambers and turbines resulting in the first commercially viable engine, the ATAR 101B, which, along with later marques, powered the SNCASO S.O.4050 Vautour interceptor/bomber/reconnaissance aircraft. Improved models continued to be developed throughout

75-502: A combination of jet and rocket power. The rocket would be used for performance at high altitude, increasing either speed or ceiling. French studies for mixed-power interceptors began in 1948. By 1953 the SNCASO Trident aircraft was flying. This was an unusual design, with a single three-chambered SEPR rocket engine as the main engine, assisted for take-off and low altitude flight by two Turbomeca Marboré turbojets. The Trident

100-399: A fuel, in the ratio of 2.4:1. Later fuels were a mixture of 41% furfuryl alcohol, 41% xylidine and 18% methyl alcohol , called furaline. Unusually, the turbopumps for some of SEPR's engine were mechanically driven from outside. A mechanical drive shaft from the accessory drive of the main turbojet provided the 93 brake horsepower (69 kW) needed at 5,070 rpm, provided that

125-608: A half-thrust setting. The Mirage and its distinctive delta wing planform began with the prototype MD.550 Mystère-Delta . This bore little relation, other than its name, to the Dassault Mystère ; France's swept-wing fighter of the period. The delta aircraft was smaller, around two thirds of the Mystère's weight and was powered by two small Viper turbojets and the SEPR 66 rocket. All three of these engines barely exceeded

150-482: Is different from Wikidata All article disambiguation pages All disambiguation pages Soci%C3%A9t%C3%A9 d%27Etudes pour la Propulsion par R%C3%A9action The SEPR 841 is a liquid-fuelled rocket engine used as an auxiliary power unit for the Dassault Mirage III mixed-power high-altitude interceptor aircraft of the 1960s. The engine was one of several similar developed by SEPR. In

175-631: The 1950s, there was much concern in Western Europe about attacks by fleets of high-flying bombers, such as the Tu-95 Bear . These pre-dated the development of either practical afterburners or surface-to-air missiles and so means to improve the performance of conventional aircraft were sought. Particularly in France, and to some extent in the UK, mixed-power interceptor aircraft were studied, with

200-466: The ATAR 101 by October 1945. A contract for development of the engine was awarded in December 1945, a stipulation being that all manufacturing was to be carried out in France. Communications between the ATAR group and SNECMA, the newly formed nationalised engine manufacturer, proved to be difficult and the design team soon moved to Decize on the river Loire , to improve communications with SNECMA and

225-604: The French government acquired the services of a large contingent of German design engineers and technicians. Some of these engineers formed the Atelier Technique Aéronautique de Rickenbach, led by Dr. Hermann Östrich who had been developing gas turbine engines at BMW. By September the team was housed at the Dornier factory at Rickenbach near Lindau on Lake Constance and had largely completed design of

250-426: The engine was running at full speed. As the propellants are hypergolic, the engine can be ignited repeatedly simply by engaging the clutch drive to the pump. The engine's single combustion chamber was regeneratively cooled by the acid oxidiser. The 841 used TX2 ( triethylamine xylidine ) as a fuel. The engine was designed for simplicity and reliability, rather than sophisticated control. The pilot's only control

275-442: The engine. For reliable hypergolic ignition, a small TX tank was retained to supply the engine's pilot ignition valve. This fuel supply was controlled very simply, by displacement under fuel pressure acting on a piston in the tank. TX capacity limited the engine to just two or three starts per flight. The forward bay tank could also be used as an additional fuel tank for the main jet engine. The main tankage could not though supply

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300-528: The first flight-ready ATAR 101A flew in the fuselage of a Martin B-26G Marauder (F-WBXM). Steady progress was made by Groupe O, but they were soon absorbed into SNECMA during a massive re-organisation of the nationalised company in June 1950. Other aircraft joined the flight test program, including two SNCASE S.E.161 Languedoc airliners, a SNCASO S.O.30P Bretagne (F-WAYD), SNCASE S.E.2060 Armagnac and

325-405: The rocket and 1.8 with. Altitudes of 65,000 feet (20,000 m) could be reached in a zoom climb, or 75,000 feet (23,000 m) on rocket thrust. A typical training sortie duration of 45 minutes would be reduced to under 30, with high Mach and rocket use. SEPR's auxiliary rocket engines were based on hypergolic fuel chemistry of 98.5% nitric acid (HNO 3 ) oxidiser with furfuryl alcohol as

350-435: The rocket and could not afford its fuel consumption. The original goal of intercepting high-flying bombers also seemed to be receding in favour of missiles, for both offence and defence. The Mirage's rocket was thus mounted as a removable pod which could be replaced with a 90 imperial gallons (410 L) jet fuel tank for additional range. Only the high altitude interception would still use it. To retain balance as rocket fuel

375-436: The rocket oxidiser was potentially somewhat hazardous and so it was carried out away from other aircraft, by groundcrew in protective clothing and with a fire crew standing by in order to flush away any spillage. Acid refuelling was carried out above a steel drip tray, with the acid flow and tank vent return through closed pipework with a sightglass to observe full tanks. Performance in training sorties achieved Mach 1.4 without

400-576: The rocket. Replacing both rocket and cannon with the fuel tanks gave additional ferry range. SNECMA Atar 101 The SNECMA ATAR 101 is a French axial-flow turbojet engine built by SNECMA . It was derived from engines and design work carried out at BMW in Germany during World War II , and extensively developed though a progression of more powerful models. The name is derived from its original design group, Atelier Technique Aéronautique de Rickenbach employing Hermann Östrich and many of

425-404: The same term [REDACTED] This disambiguation page lists articles associated with the title SEPR . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=SEPR&oldid=470812773 " Category : Disambiguation pages Hidden categories: Short description

450-402: The stored air supply which then opened the pneumatic LP cocks. A second valve, after a delay, engaged the turbopump clutch. HP cocks were opened by a single hydraulic piston, driven by fuel pressure controlled through a third timed valve. Both fuel and oxidiser first flowed through a small pilot valve for ignition, before their main valves opened. Correct opening of all four valves was monitored by

475-412: The thrust of the Mystère's ATAR 101D , although they also only weighed about half of the ATAR. The Mirage III adopted the more developed and afterburning ATAR 9 . As the delta wing considerably increased the supersonic capacity of the aircraft, rocket power was retained. This was the first European aircraft to exceed Mach 2 in level flight. It was recognised that most mission profiles did not require

500-449: The timer control, to ensure a safe mixture. A dump valve system was provided for any residual acid. Oxidiser loaded was burned in flight before landing, or dumped. Bulk production of the engines was carried out by Hispano-Suiza . For simplicity of fuel supply, the TX2 fuel of the SEPR 84-1 was replaced with standard jet TR-0 kerosene as the SEPR 84–4. This required a few changes to

525-743: The wartime BMW gas turbine design group as well as other German engine design teams. The ATAR 101 powered many of the French post-war jet aircraft, including the Vautour II , Étendard IV , Super Mystère B2 , and the Mirage III-001 , prototype of the Mirage III series. At the end of World War II the French aircraft industry was in disarray, having been commandeered by the German government to produce mostly German designed aircraft and aero-engines. To develop an indigenous gas turbine aero-engine

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550-464: Was a simple on/off switch, with the valves and pump then controlled by an electromechanical timer. Power for actuating the main valves was then obtained by a compressed air bottle or fuel pressure. The tanks were air pressurised, the fuel tank by engine compressor bleed air and the oxidiser tank by ram air and additionally by the stored air bottle. Ram air was taken from the supersonic inlet boundary layer bleeds. A single timer-controlled valve opened

575-496: Was consumed, the rocket pack was in two parts. The 310 litres (69 imp gal) nitric acid oxidiser tank was mounted directly ahead of the rocket engine. A smaller 150 litres (32 imp gal) TX2 Furaline fuel tank was mounted in the front bay just behind the cockpit, replacing the cannon pack. When in the rocket-powered interceptor role, the aircraft would only be armed with missiles. The rocket pack could be swapped in around 20 minutes by removing six bolts. Fuelling

600-613: Was difficult to handle on the low-powered turbojets alone and was thirsty for fuel on rocket power. This primary use of the rocket was not repeated in the future: later aircraft would be jet-powered, with the rocket reserved for high-speed dashes. Later rockets would also be considerably less powerful than the Trident's SEPR 48–1. A development for the Trident II aircraft was the two chamber SEPR 631 engine. The two chambers could be fired separately. Although not throttleable, this did give

625-532: Was renamed Aeroplanes G.Voisin, Groupe 'O' . Manufacture of components for the ATAR 101 V1 commenced at SNECMA plants in May 1946 and the first run was carried out on 26 March 1948. The early engines were constructed from ordinary commercial steels and suffered from very short running lives, not achieving a 150-hour endurance test until 1951. As more exotic materials were introduced the durability and reliability of test engines improved dramatically and on 10 November 1950

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