المعرفة

مرلن (طراز محركات صواريخ)

(تم التحويل من Merlin (rocket engine))

Merlin is a family of rocket engines developed by SpaceX for use on its Falcon 1 and Falcon 9 launch vehicles. SpaceX also plans to use Merlin engines on its Falcon Heavy. Merlin engines use RP-1 and liquid oxygen as rocket propellants in a gas-generator power cycle. The Merlin engine was originally designed for sea recovery and reuse.

Merlin 1D
Test firing at SpaceX McGregor's test stand of the Merlin 1D
بلد الأصلالولايات المتحدة
الصانعSpaceX
الاستخدامMain stage engine, Upper stage engine
مركبة الإطلاق المقترنةFalcon 9, Falcon Heavy
محرك وقود سائل
الدافعLOX / RP-1 (rocket grade kerosene)
الدورةgas-generator
الأداء
الدفع (فراغ)914 kN (205,000 lbf)[1]
الدفع (SL)845 kN (190,000 lbf)[1]
نسبة الدفع إلى الوزن180.1[2]
ضغط التجويف9.7 MPa (1,410 psi)[3]
دنو (فراغ)311 seconds
دنو (SL)282 s (2.73 km/s)
الأبعاد
الوزن الجاف1,030 pounds (470 kg)[2]
المراجع
المراجع[4]

The injector at the heart of Merlin is of the pintle type that was first used in the Apollo program for the lunar module landing engine (LMDE).

Propellants are fed via a single shaft, dual impeller turbopump. The turbo-pump also provides high pressure fluid for the hydraulic actuators, which then recycles into the low pressure inlet. This eliminates the need for a separate hydraulic drive system and means that thrust vectoring control failure by running out of hydraulic fluid is not possible.

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Variants

Three versions of the Merlin 1C engine have been produced. The Merlin engine for Falcon 1 had a movable turbo-pump exhaust assembly which was used to provide roll control by vectoring the exhaust. The Merlin 1C engine for the Falcon 9 first stage is nearly identical to the variant used for the Falcon 1 except that the turbo-pump exhaust assembly is not movable. Finally, a Merlin 1C vacuum variant is used on the Falcon 9 second stage. This engine differs from the Falcon 9 first stage variant in that it uses a larger exhaust nozzle optimized for vacuum operation and can be throttled between 60 and 100 percent.[5]


Revisions

Merlin 1A

 
SpaceX Merlin 1A

The initial version, the Merlin 1A, used an inexpensive, expendable, ablatively cooled carbon-fiber-reinforced polymer composite nozzle, and produced 340 kN (77,000 lbf) of thrust. The Merlin 1A flew only twice: First on March 24, 2006, when it caught fire and failed due to a fuel leak shortly after launch,[6][7] and the second time on March 21, 2007, when it performed successfully.[8] Both times the Merlin 1A was mounted on a Falcon 1 first stage.[9][10]

مرلن 1C

Merlin 1C
 
Merlin 1C under construction at SpaceX factory
بلد الأصلالولايات المتحدة
الصانعSpaceX
الاستخدامMain stage engine, Upper stage engine
مركبة الإطلاق المقترنةFalcon 9
محرك وقود سائل
الدافعLOX / RP-1 (rocket grade kerosene)
الدورةGas-generator
الأداء
الدفع (فراغ)480 kN (110,000 lbf)[11]
الدفع (SL)420 kN (94,000 lbf)[11]
نسبة الدفع إلى الوزن96
ضغط التجويف6.77 MPa (982 psi)[5]
دنو (فراغ)304.8 s (3.0 km/s)[5]
دنو (SL)275 s (2.6 km/s)
الأبعاد
الطول2,920 mm (115 in)[12]
الوزن الجاف1,380 pounds (630 kg)

The Merlin 1C uses a regeneratively cooled nozzle and combustion chamber. The turbopump used is a Merlin 1B model with only slight alterations. It was fired with a full mission duty firing of 170 seconds in November 2007,[11] first flew on a mission in August 2008,[13] powered the "first [[private spaceflight|privately- [ك‍]developed]] liquid-fueled rocket to successfully reach orbit", Falcon 1 Flight 4, in September 2008,[13] and powered the Falcon 9 on its maiden flight in June 2010.[14]

Merlin Vacuum (1C)

 
Merlin 1C Vacuum engine at Hawthorne factory in 2008

On March 10, 2009 a SpaceX press release announced successful testing of the Merlin Vacuum engine. A variant of the 1C engine, Merlin Vacuum features a larger exhaust section and a significantly larger expansion nozzle to maximize the engine's efficiency in the vacuum of space. Its combustion chamber is regeneratively cooled, while the 2.7 metres (9 ft)-long[15] niobium alloy[5] expansion nozzle is radiatively cooled. The engine delivers a vacuum thrust of 411 kN (92,500 lbf) and a vacuum specific impulse of 342 seconds.[16] The first production Merlin Vacuum engine underwent a full duration orbital insertion firing (329 seconds) of the integrated Falcon 9 second stage on January 2, 2010.[17] It was flown on the second stage for the inaugural Falcon 9 flight on June 4, 2010. At full power the Merlin Vacuum engine operates with the greatest efficiency ever for an American-made hydrocarbon rocket engine.[18]

Merlin 1D

The Merlin 1D engine was developed by SpaceX in 2011–2012, with first flight in 2013. The Merlin 1D was originally (April 2011) designed for a sea level thrust of 620 kN (140,000 lbf).[19] In 2011, it was revealed[20] that the engine would have a vacuum thrust of 690 kN (155,000 lbf), a vacuum specific impulse (Isp) of 310 s, an increased expansion ratio of 16 (as opposed to the previous 14.5 of the Merlin 1C) and chamber pressure in the "sweet spot" of 9.7 MPa (1,410 psi). A new feature for the engine is the ability to throttle from 100% to 70%.[3] Later refinements of the Merlin 1D have been operated down to 40% of full thrust.[21]

Merlin 1D Vacuum

A vacuum version of the Merlin 1D engine was developed for the Falcon 9 v1.1 and the Falcon Heavy second stage.[22][3]

Design

Engine control

SpaceX uses a dual-redundant design in the Merlin flight computers. The system uses three computers in each processing unit, each constantly checking on the others, to instantiate a fault-tolerant design. One processing unit is part of each of the ten Merlin engines (nine on first stage, one on second stage) used on a Falcon 9 launch.[23]

Turbopump

The Merlin LOX/RP-1 turbopump used on Merlin engines 1A–1C was designed and developed by Barber-Nichols.[24]

Production

اعتبارا من أغسطس 2011, SpaceX was producing Merlin engines at the rate of eight per month, planning eventually to raise production to about 33 engines per month (or 400 per year).[3] By September 2013, SpaceX total manufacturing space had increased to nearly 93,000 square meters (1,000,000 sq ft) and the factory had been configured to achieve a maximum production rate of up to 40 rocket cores per year, enough to use the 400 annual engines envisioned by the earlier engine plan.[25] By October 2014, SpaceX announced it had manufactured the 100th Merlin 1D engine and that engines were now being produced at a rate of 4 per week, soon to be increased to 5.[26]


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See also

References

  1. ^ أ ب "SpaceX Falcon 9 product page". Retrieved May 4, 2015.
  2. ^ أ ب خطأ استشهاد: وسم <ref> غير صحيح؛ لا نص تم توفيره للمراجع المسماة quora-M1Dquestion
  3. ^ أ ب ت ث "SpaceX Unveils Plans To Be World's Top Rocket Maker". AviationWeek. August 11, 2011. Retrieved June 28, 2014. {{cite news}}: Unknown parameter |deadurl= ignored (|url-status= suggested) (help)
  4. ^ خطأ استشهاد: وسم <ref> غير صحيح؛ لا نص تم توفيره للمراجع المسماة spacexfalcon9Merlinpage
  5. ^ أ ب ت ث (2008) "Low-cost Launch Opportunities Provided by the Falcon Family of Launch Vehicles" (PDF) in Fourth Asian Space Conference.. 
  6. ^ Berger, Brian (July 19, 2006). "Falcon 1 Failure Traced to a Busted Nut". Space.com.
  7. ^ "Findings of the Falcon return to flight board". SpaceX.com. July 25, 2006. Archived from the original on 2013-03-03. {{cite news}}: Unknown parameter |deadurl= ignored (|url-status= suggested) (help)
  8. ^ "Demo Flight 2 Flight Review Update" (PDF). SpaceX. June 15, 2007. Archived from the original (PDF) on 2012-03-06. {{cite web}}: Unknown parameter |deadurl= ignored (|url-status= suggested) (help)
  9. ^ Whitesides, Loretta Hidalgo (November 12, 2007). "SpaceX Completes Development of Rocket Engine for Falcon 1 and 9". Wired Science. Retrieved February 28, 2008.
  10. ^ Gaskill, Braddock (August 5, 2006). "SpaceX has magical goals for Falcon 9". Nasa Spaceflight. Retrieved February 28, 2008.
  11. ^ أ ب ت "SpaceX Completes Development of Merlin Regeneratively Cooled Rocket Engine". Business Wire. November 13, 2007.
  12. ^ "The SpaceX Falcon 1 Launch Vehicle Flight 3 Results, Future Developments, and Falcon 9 Evolution" (PDF). Retrieved December 29, 2012.
  13. ^ أ ب Clark, Stephen (September 28, 2008). "Sweet Success at Last for Falcon 1 Rocket". Spaceflight Now. Retrieved April 6, 2011. the first privately- [ك‍]developed liquid-fueled rocket to successfully reach orbit.
  14. ^ Boyle, Alan (June 4, 2010). "Shuttle successor succeeds in first test flight". MSNBC. Retrieved June 5, 2010.
  15. ^ خطأ استشهاد: وسم <ref> غير صحيح؛ لا نص تم توفيره للمراجع المسماة aw20101213
  16. ^ SpaceX (March 10, 2009). "SpaceX Falcon 9 upper stage engine successfully completes full mission duration firing.". Press release. Archived from the original. You must specify the date the archive was made using the |archivedate= parameter. http://www.spacex.com/press/2012/12/19/spacex-falcon-9-upper-stage-engine-successfully-completes-full-mission-duration. Retrieved on March 12, 2009. 
  17. ^ Full Duration Orbit Insertion Firing. SpaceX. January 2, 2010.
  18. ^ "SpaceX Falcon 9 Upper Stage Engine Successfully Completes Full Mission Duration Firing". SpaceX. March 10, 2009. Retrieved May 31, 2016.
  19. ^ Harwood, William (April 5, 2011). "World's biggest private space rocket planned". CBS. Retrieved April 5, 2011.
  20. ^ Lindsey, Clark S. (August 1, 2011). "SpaceX Merlin 1D". Archived from the original on October 11, 2012. Retrieved August 6, 2011. {{cite web}}: Unknown parameter |deadurl= ignored (|url-status= suggested) (help)
  21. ^ https://twitter.com/elonmusk/status/728753234811060224
  22. ^ "SpaceX Falcon 9 product page". Retrieved November 1, 2015.
  23. ^ Svitak, Amy (November 18, 2012). "Dragon's "Radiation-Tolerant" Design". Aviation Week. Archived from the original on 2013-12-03. Retrieved November 6, 2013. "We've got computers in the Falcon 9, we've got three computers in one unit on each engine in the Falcon 9, so that's 30 computers right there." {{cite news}}: Unknown parameter |deadurl= ignored (|url-status= suggested) (help)
  24. ^ "Merlin LOX/RP-1 Turbopump". website "Products" page: Rocket Engine Turbopumps. Barber-Nichols. Retrieved November 22, 2012.
  25. ^ "Production at SpaceX". SpaceX. September 24, 2013. Archived from the original on 2016-04-03. Retrieved September 30, 2013. {{cite web}}: Unknown parameter |deadurl= ignored (|url-status= suggested) (help)
  26. ^ "SpaceX Completes 100th Merlin 1D Engine". SpaceX. October 22, 2014. Archived from the original on 2016-04-04. Retrieved October 16, 2014. {{cite web}}: Unknown parameter |deadurl= ignored (|url-status= suggested) (help)
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