Vulcain (rocket engine)
Vulcain [ vyl.kɛ ] is a rocket engine of the ESA , which in the first stage of Ariane 5 is used. There are two main versions of this engine, Vulcain 1 and Vulcain 2 , as well as a variant of the Vulcain 1, the Vulcain 1B . The name of the engine corresponds to the French name for the Roman god Vulcanus .
development
As early as 1957, the French Ministry of Defense decided to develop a cold-temperature engine for rockets. The first prototype was put into operation in 1964. Several generations of the engine have been developed since then. At the ESA Ministerial Conference in The Hague in 1987, it was decided to develop a more powerful launcher , the Ariane 5. For this, a new engine, the Vulcain engine (formerly HM-60), had to be built. After a relatively short development period by Snecma and EADS Astrium (formerly MBB ), the first Vulcain engine was ignited in April 1990, which was used for the first time in a launch vehicle on June 4, 1996. A slightly modified version of the engine called Vulcain 1B was used for the Ariane 5 GS. An increase in the combustion chamber pressure by 10 bar provided 20 kN more thrust.
A more powerful engine was desired for the larger Ariane 5 ECA due to the increased weight of the upper stage, and so the successor, the Vulcain 2, was developed as early as the late 1990s. During the first flight on December 11, 2002, the nozzle failed structurally as a result of excessive thermal stress on the tube structure with which the nozzle is cooled, resulting in cracks in the thrust nozzle, loss of coolant and burning through of the tube structure. In addition, axial buckling under vacuum conditions damaged the nozzle. Then the engine had to be improved. Vulcain 2 was not successful until its second use on February 12, 2005.
Technical specifications
The further development of the Vulcain 2 has increased the performance data in almost all areas. The aim was to be able to carry more fuel with the Ariane 5 with the same total tank volume . Due to the large difference in density between liquid oxygen and liquid hydrogen, the intermediate floor that separates the two fuels has been shifted in favor of the oxygen volume. This makes it possible to carry 16 t of additional oxygen with you if 1 t of hydrogen is lost. In order to be able to deliver this additional amount of fuel, the performance of the oxygen turbo pump has been increased and the number of injection nozzles increased. This measure would reduce the specific impulse slightly. This was compensated for by increasing the combustion chamber pressure and lengthening the exhaust nozzle. As a further performance-enhancing measure, the exhaust gases from the gas generator are blown into the lower part of the nozzle after flowing through the turbines, which slightly increases the thrust and specific impulse and also cools the nozzle. As a result, Vulcain 2 no longer works according to the classic bypass flow method, but rather according to the bypass flow method with exhaust gas re-injection.
| version | Vulcain 1 (Vulcain 1B) | Vulcain 2 |
|---|---|---|
| height | 3 m | 3.45 m |
| diameter | 1.76 m | 2.10 m |
| Dimensions | 1686 kg | 2100 kg |
| Fuels | Liquid oxygen ( LOX ) and hydrogen ( LH2 ) in a ratio of 5.9: 1 | Liquid oxygen (LOX) and hydrogen (LH2) in a ratio of 6.1: 1 |
| Speed of the turbo pumps | 11000-14800 min -1 (LOX) or 28,500 to 36,000 min -1 (LH2) |
11300-13700 min -1 (LOX) or 31,800 to 39,800 min -1 (LH2) |
| Turbo pump power | 2.0 - 4.8 MW (LOX) or 7.4 - 15.5 MW (LH2) | 3.7 - 6.6 MW (LOX) or 9.9 - 20.4 MW (LH2) |
| Combustion chamber pressure | 100 bar (110 bar) | 117.3 bar |
| Vacuum thrust | 1120 kN (1140 kN) | 1359 kN |
| Ground thrust | 815 kN | 960 kN |
| Specific impulse in vacuum ( SI ) | 4228 m / s | 4207 m / s |
Planned further development
Due to the assumed increase in payload masses, the performance of the Vulcain engine is to be increased as part of the further development of Ariane 5. In addition, the production costs of the engine are to be reduced in order to remain competitive on the international market. In order to achieve these goals, various studies have been carried out by the manufacturers SNECMA and CNES . The specific impulse is increased by up to 3.7% depending on the variant. Using such an engine on an Ariane 5 would increase the payload in a low orbit ( LEO ) by up to 3.4 t.
For the Ariane 6 , a further development called "Vulcain 2.1" is planned as the main stage.
Web links
- Official ESA page about the engine
- EADS Astrium: Vulcain Rocket Engine - Thrust Chamber (English)
- EADS Astrium: Vulcain 2 Rocket Engine - Thrust Chamber (English)
- CAPCOM ESPACE: Le Moteur Vulcain (French)
- Capcom Espace: Le Moteur Vulcain 2 (French)
References
- ↑ Supplier for ArianeGroup. (PDF; 5.1 MB) In: inForm, edition 2017. Otto Fuchs KG , p. 18 , accessed on January 12, 2020 .
- ^ Zach Rosenberg: What's in a Name? In: Air & Space / Smithsonian . April 14, 2015, accessed January 12, 2020 .
- ↑ Vulcain engine article on esa.int of November 29, 2005.
- ↑ Prof. Wolfgang Koschel in the magazine of the Aerospace Center, July 2005, page 19 (PDF; 9.7 MB)
- ↑ Expansion of the Ariane 5 article from bernd-leitenberger.de
- ↑ The Ariane 5 article from bernd-leitenberger.de
- ^ First ignition for Europe's most powerful rocket engine, Vulcain 2.1. In: News. DLR , January 23, 2018, accessed on January 12, 2020 .