Chinese SABRE technology

• Chinese SABRE technology by Mutley on 29 Nov, 2021 09:32
• https://twitter.com/LMRockets/status/1464207364953804800
  
  [Are the Chinese are actively copying the precooler technology?  Or is this an independent development?]
  
  [zubenelgenubi: Splinter thread split, post edited.]
  
  
• #1 by edzieba on 30 Nov, 2021 10:19
• Unless Reaction Engines have a Chinese factory producing their heat exchanger, this is not just an 'off brand' SABRE HEX.
  The idea of "have a heat exchanger to pre-chill inlet air" is neither new nor novel, nor is the use of tiny tubes to create your heat exchanger (e.g. RB545 back in the 80s). Putting the work in to design one that works is the hard part, and there is no reason China cannot have done so.
• #2 by zubenelgenubi on 01 Dec, 2021 19:01
• Moderator: Splinter thread created from the current SABRE discussion thread.
• #3 by Asteroza on 02 Dec, 2021 01:39
• Precooled engine work was on the big chinese national project list recently apparently so it's a real priority, and not just sabre rattling...
  
  
  EDIT
  
  oh god the dad joke...
  
  I'll be here all week, try the veal!
• #4 by luhai167 on 02 Dec, 2021 07:31
• This engine was already tested in April of this year, though the latest one is the first time it was tested in Mach 5.
  
  http://m.stdaily.com/index/kejixinwen/2021-04/16/content_1115807.shtml
• #5 by JCRM on 02 Dec, 2021 08:38
• Quote from: luhai167 on 02 Dec, 2021 07:31

  This engine was already tested in April of this year, though the latest one is the first time it was tested in Mach 5.
  
  http://m.stdaily.com/index/kejixinwen/2021-04/16/content_1115807.shtml
  

  
  Engine or precooler tested?
  
  tasted at Mach 5, or tested in post-intake conditions expected at Mach 5?
• #6 by luhai167 on 03 Dec, 2021 00:47
• Quote from: JCRM on 02 Dec, 2021 08:38

  Quote from: luhai167 on 02 Dec, 2021 07:31

  This engine was already tested in April of this year, though the latest one is the first time it was tested in Mach 5.
  
  http://m.stdaily.com/index/kejixinwen/2021-04/16/content_1115807.shtml
  

  
  Engine or precooler tested?
  
  tasted at Mach 5, or tested in post-intake conditions expected at Mach 5?
  

  
  in the april article, the title says engine tested, however, the article itself only talk about precooler.
  
  For the nov test, the description is ma=5 dynamic thermal test, so i believe it is post-intake conditions expected at Mach 5.
  
  Both article talk about cooling the it cooling 1000℃ in under 0.01 second, so i'm not 100% sure what's the exact difference between the two tests. The name of the engine is called yunlong, “云龙”发动机.
  
  this article has a time for the project, however I'm not sure how reliable the source is.
  
  https://news.mydrivers.com/1/798/798957.htm
  
  2021年4月，31所研制的组合动力发动机——“云龙”发动机的预冷装置已经完成了目前国内最大尺度、最大空气流量的温降试验，试验结果超出预期。
  
  2020年，31所完成了该型发动机原理样机的整机试制，并通过了第一阶段的系统级地面试验验证。该型发动机多项关键技术攻关获得突破。
  
  2018年，三院负责人曾对媒体公开表示，我国正在研制一种用于天地往返运输并可重复使用的“空天飞机”。按计划，“云龙”发动机将为空天往返飞行器提供动力。
  
  google translation
  
  In April 2021, the pre-cooling device of the "Yunlong" engine, a combined power engine developed by 31, has completed the temperature drop test with the largest scale and the largest air flow rate in China, and the test results exceeded expectations.
  
  In 2020, 31 Institute completed the trial production of the prototype of this type of engine, and passed the first phase of the system-level ground test verification. A number of key technological breakthroughs have been made for this type of engine.
  
  In 2018, the heads of the three institutes publicly stated to the media that my country is developing a reusable "air-to-sky plane" for transportation between the sky and the earth. According to the plan, the "Yunlong" engine will provide power for the aerospace shuttle.
• #7 by edzieba on 03 Dec, 2021 14:14
• From the sounds of it, the April test was of the precooler alone cooling Mach-5 inlet condition air down to operating temperatures. The recent test (assuming the image in the OP is of the test setup) adds a combustion chamber downstream of the precooler to ingest and combust with the inlet air. The April test would be the equivalent of Reaction Engine's HEX test in Colorado in Oct '19, and the latter closer to Demo-A.
• #8 by JCRM on 04 Dec, 2021 15:46
• Quote from: edzieba on 03 Dec, 2021 14:14

  The recent test (assuming the image in the OP is of the test setup) adds a combustion chamber downstream of the precooler to ingest and combust with the inlet air.
  

  Unless that turbojet combustion chamber is *up*stream of the pre-cooler, in which case it is still the equivalent of the Colorado tests. With no date or reference in the tweet it might even be the April tests it is referring to.
• #9 by edzieba on 04 Dec, 2021 18:18
• Quote from: JCRM on 04 Dec, 2021 15:46

  Quote from: edzieba on 03 Dec, 2021 14:14

  The recent test (assuming the image in the OP is of the test setup) adds a combustion chamber downstream of the precooler to ingest and combust with the inlet air.
  

  Unless that turbojet combustion chamber is *up*stream of the pre-cooler, in which case it is still the equivalent of the Colorado tests. With no date or reference in the tweet it might even be the April tests it is referring to.
  

  For that, you'd need the entire turbojet (including the compressor) rather than just the combustion chamber. The J79 on the HEX test stand was a hot high velocity gas source, which a combustion chamber on its own would not produce.
• #10 by JCRM on 05 Dec, 2021 09:29
• Quote from: edzieba on 04 Dec, 2021 18:18

  Quote from: JCRM on 04 Dec, 2021 15:46

  
  Unless that turbojet combustion chamber is *up*stream of the pre-cooler, in which case it is still the equivalent of the Colorado tests. With no date or reference in the tweet it might even be the April tests it is referring to.
  

  For that, you'd need the entire turbojet (including the compressor) rather than just the combustion chamber. The J79 on the HEX test stand was a hot high velocity gas source, which a combustion chamber on its own would not produce.
  

  Given how badly the English speaking media has reported on Reaction Engine's development, I don't think it's too surprising that Chinese reporting passed through a machine translation service is unclear.
  
  The Colorado tests were a hot but subsonic air source.
  I don't know anything about 31 institute, or their facility, but a compressor would only be needed of there wasn't a sufficient compressed air source amongst all that industrial piping.
  
  If that was a SABRE style precooler, with inward radial flow, then the cone is the wrong way round for that to be a post cooler combustion chamber, and if it were a SABRE style engine, it would need a compressor after the precooler before the combustion chamber.
  
  However, here is a different source reporting the story, which seems much clearer that it is just the precooler they are testing:
  https://www-163-com.translate.goog/dy/article/GPRGMREI0552PMBQ.html?f=post2020_dy_recommends&_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=en-GB
  
  It suggests they will catch up to the west in two years, (because "we" only conducted out mach 5 test two years ago?) and that they are investing in the technology so they aren't militarily outmatched
  
  

  Quote from: Google Translate

  The success of the precooler indicates a breakthrough in the key equipment of the domestic "Yunlong" engine. This Yunlong engine is a future-oriented domestic reusable single-stage/two-stage on-orbit vehicle of AVIC 31, which is what we commonly call the sky and sky. The standard power unit of the aircraft. Of course, other aircraft that need to operate in the atmosphere and into orbit at the same time can also be used, such as orbital bombers. Once the West has mastered the technology, it can achieve global reach and its own aircraft can appear anywhere in the world at any time. This constitutes a great condition for the currently obscure orbital ownership. That is to say, this technology has the West. , We must also have, otherwise it is easy to be controlled by others.
• #11 by luhai167 on 05 Dec, 2021 18:39
• Quote from: JCRM on 05 Dec, 2021 09:29

  I don't know anything about 31 institute, or their facility, but a compressor would only be needed of there wasn't a sufficient compressed air source amongst all that industrial piping.
  

  
  It does have the JF-12 shock tunnel can produce air source up to 3000C, speed up to mach 9 for 100ms and cross section up to 3.5 meters. Here is an open source article for the tunnel on a shock cone test. That facility has been running since 2012, the institute is also bring online a more capable wind tunnel JF-22 that's due for certification sometime next year.
  
  
  
  The facility also has a huge number of hypersonic and high supersonic test facilities, but all those information have been taken down on their latest website. you can get a glimpse of it on their achieved 2016 website. I doubt air source would be a problem, as it it could be tested on any number of those.
  
  
  
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  never mind, found another article that indicate the test happen at 北京云岗某试验台 rather than at the CASIC centralized test facility i talked about above. So it is like an unknown test platform, since site normally do tests for rocket engines. Also a side find while searching is a weibo post from china aerospace news for successful test field for that exact team. The flag in the photo indicate they are air to space combine cycle test team...