Chinese Engine Development
- Thread starter jackbh
- Start date
This picture might be showing the unknown engine that has been fit on the J-20 Prototype, if you look a the color of the nozzle, maybe they are going to fit another engine than standard WS-10 for J-11 and J-10 ? Opinions ?
Quickie
Colonel
Probably because of distortion effect of camera lens. They look quite the same if you concentrate on the different shade of bands, its width, around the nozzles.
We seem to be getting more and more pictures of a flying WS-10 engine.
maozedong
Banned Idiot
they are the same engines, just different angle of vision, clearly they are Ws-10.
see post#1134 in this page, J-11BS photos, the engines looks like different but actually they are the same.
http://www.sinodefenceforum.com/air-force/china-flanker-thread-ii-76-3720.html
pugachev_diver
Banned Idiot
The UNKNOWN History of Chinese Jet Engines
Here is the original text I have read on an oversea Chinese website. I know it's long and contain a lot of information, so I'll try my best to translate this as detailed as my time allow me.
Note that there are a lot of languages used in this post are slangs and idioms unique to Chinese culture and language, so I will change it a bit so that everyone here can understand it. Also note that I have left China since I was 10 years old, so if any other Chinese friends see me making stupid mistakes, please just forgive me and let me know that I have done something wrong.
关于中国航空发动机领域一些鲜为人知的事情
高科技，尖端科技多了，为什么航空发动机是工业之花？空间技术，火箭技术，核电技术，微电子技术，都有各自的特点和难点，为什么他们不是工业之花？
我们来做个比喻，整个国家的第二产业（从冶金到制造到加工，设计）是一个金字塔，航发就是这个金字塔的塔尖，它涉及到了基本上所有的工业和技术项目，并且要用到这些领域的最高技术成就。其实，使航发技术的发展，在带动着整个工业的进步。
说到这里，想象一下，如果我们的航空发动机技术有一天独步全球，那我们就TMD是不折不扣的超级大国，想不承认都不行。甚至都不必象美国人一样领先，只要我们在技术上和他们平起平坐，中华民族的复兴之梦就算是跑不了了。
航发技术从大面上说，涉及到：冶金，材料，机械加工，机械制造，热力学，空气动力学，流体力学，控制学，等等等等吧，基本上吧，你把工科的学科统统算上，75％以上都要把自己的最高成就献给航发。
话说九十年代中国引进Su27生产线后，自己的J-11开始批量生产。三哥眼红了，也想要一条生产线。毛子心说，卖给谁不是卖，给钱就行，于是派专家组考察三哥的工业设施，考虑在那儿设接收点。折腾了半年，专家组的意见是，三哥现有的工业得从冶金开始，重新来过，二十年之内，不可能自己生产。（由此可见，五十年代老大哥对我们的援助是多么的重要，基础，基础啊）
八十年代，小巴装备了F-16，我们也搞过来了一架，看看还是有点帮助吧，也就仅限于此了。我们当年的工业基础，就是有全套的技术资料，也造不出来呀。除非象和老美当年蜜月期的计划一样，由美国整体援建配套工厂。当年，F-16上，怕是有一半以上的零件，我们连材料都没有，更别提加工工艺了。即便是今天，我们可能也还是有些材料和工艺上的差距。没办法呀，底子薄啊。班上学习好的，还就是几个老牌资本主义强国，工业上的差距，真的得多年的修行才可以有正果的。
说到这里，讲个小故事，当年863计划，航空部材料所有一项，粉末冶金涡轮盘。就是把金属粉末，按比例（呵呵，这个比例可是国之机密）放在容器里，高温高压下，变成合金。具有很好的结晶顺序，可以耐高温，强度也好。F404上的高压涡轮盘就是这样的，咱们就照着葫芦画瓢吧。整个项目3.5亿RMB，还不错，搞定了，大大小小的庆功会也开了不少。新材料有了，咱们也来一盘？上车床，从盘心到盘边，F404是一刀走到底，这样保证没有因为换刀时产生的痕迹，（将来就是裂纹的萌芽），可是问题是，我们的车刀的材料不行，一刀走不完，就磨没了，得换刀。这下才发现，我们还得要另一个攻关项目。
所以，我们的水桶，每一块板都不够长，这个水桶就是我们的工业能力，我们正在集中力量，加高每一块板，尤其是那些相对更短的板。两弹一星只是一个相对独立的项目，可以集中力量办大事，（即便是这样，也有很多土法上马的例子）。而整个工业能力的提升，又怎样集中力量办大事哪？
（二）尴尬时期
我们的航空发动机，建国前，是空白，比白纸还白，一穷二白。五十年代从朝鲜战争起，开始修发动机，战后，由于我们志愿军将士的英勇牺牲，我们在老大哥那里，基本上属于有栽培潜力的了。
随后的156个项目，是人类历史上最激烈，最彻底的工业化。沈阳的黎明厂(有幸在那实习了一个夏天，沈阳的狗肉和试车的轰鸣，一起记录在我们青春的回忆中) 就是156之一。
不到十年，我们就在表面上（注意，是表面上）赶上了世界先进水平。60年代初的Mig21仿制成功，我们在涡喷发动机上也拥有了双转子轴流式涡喷的先进水平。
可是，知其然不知其所以然。老大哥一撒手，我们就抓了瞎。对于原设计的任何改动，都会引发多米诺骨牌式的连锁反应。加上文革的折腾，我们用了20年，才在 80年代初，成功地吃透了MIG21和涡喷7的技术，并推出了成功的改进型号。歼7G被誉为世界上改的最好的MIG21。可惜晚了二十年。
即便是在被封锁的最严的60，70 年代，TG从来没有放弃引进技术。两个中队的歼6从埃及换来了MIG23，从MIG23上仿制的WP15至今是TG最大推力的涡喷，只是一直没有合适的机型。花巨额外汇（当年）引进的斯贝生产线，使得西安的430一直是三机部加工工艺最好的工厂。（老大哥当年的工艺就不如约翰牛）Spey也是没有装机。但是，WP15和Spey都给了我们很多启发和具体技术，工艺上的提升。
隔壁小胖的作业早就抄不上了，我们在70年代末和班上最优秀的同学结成了一对一，一对红，美利坚同学的作业让人眼花缭乱，每道题又要花大价钱才给抄，一时半会不知道先抄那道题好。（NND，咱穷啊）
到了风波的春夏之交，我们一道和平典范的题才抄了半，老美翻脸了，把我们的作业本都扣了。但我们好歹还是瞄了两眼，大体知道了他的解题思路（美军标，设计规范，航空部后来颁发的设计标准，简直就是美军标的翻译版。）
TG野路子走惯了，从来不按牌理出牌。在蜜月期，也没有闲着搞小动作。民航买了一批737，装CFM56，其核心机就是GE的F100（两台装F-15）的核心机。核心机就是高压压气机，燃烧室，高压涡轮组成的，又叫燃气发生器。都模块化后，可以和外围的风扇，低压压气机组成一个系列的型号。这个 CFM56买的，也是我们摆事实，讲道理，美国国会和巴统特批的。批之前，就有人说，TG要是偷我们的技术怎么办，blah, blah. 可是哪有卖飞机不给卖备用发动机的？波音的游说集团，我们朋友大大的。
这批发动机，封在箱子里，美方每半年来查一次。（NND，记得休斯公司的卫星吗，3个CIA24小时日夜监守，最终也没能下的去手），这，能难得住我们英雄的中国人民吗？
拆箱，编号，直运沈阳，测绘，建模，组装，运回北京，上封条， 不到五个月，搞定。
（二）之外篇·发动机书场·美帝兴师问罪
这么大的项目，不知道才怪了，人家的情报部门也不是吃干饭的。但是，他没有证据，没有，没有，就是没有，你看见了？国家间，往往也就是幼儿园的交际水平。
知道有一天，美帝拿着咱航空部的红头文件来兴师问罪了，文件的标题是“关于做好CFM56核心机测绘工作的指示”，我，我倒！这是谁干的！
我当是谣言听来的，您也就当时说书的听吧。沈阳606所的一个处长的儿子，不长进，但还有点想
法，不甘于过一般小混混的生活。他知道我们当时有重点型号，和美帝有关，就留了心眼儿，有一天，偷了他爹的钥匙，找了这份文件，直接就上了领事馆，要求避难。
可以想象，TG当时还是很被动的，尤其是90年代，还处在想和人修复关系的阶段，记得朱总的消气之旅吗？要搁现在，老子就是做了，你怎么着吧？具体怎么把这事私了了，就不是我所能知道的了。总之，惊动了江总，江总很生气，后果很严重。总书记亲笔批示，“要让叛国者心惊胆颤”，三个月后，美国中部小城市，车祸，一中年男子当场死亡。
（三）太行，修成正果
那位说了，切，抄个作业还这样费劲。这您就是外行了，要抄到知其然，还知其所以然，要抄到下一道题，老子我自己会做了，就不光是抄答案了，得一边抄，一边琢磨人家的解题思路，更得补以前没学过的知识。TG就象一个天赋不错的工农兵大学生，高数课上听不懂，抄作业过关，可回家就把初中，高中的课本全翻出来，恶补啊。
为什么美苏都不设防三哥？就他那点基础，还不用功，给他抄，给他把家教请来都不灵。歼6到强5，MIG21 到歼7G，歼8，Su27到歼11，TG从来就不是甘心居人篱下的主。借用虎哥一句话，只要我们自己不崩溃，成圣是早晚的事。我们要考虑的是，成圣之后，如何防止历史的循环，坠入英帝，美帝的宿命。太祖在西柏坡是怎么说的？
扯远了。
所以，CFM56 也只是给了TG一个大致的方向。整个核心机的尺寸，一模一样。小子不才，本科毕设的题目就是10A的所有叶片的动力相应分析。所有分析，计算，试验，材料，工艺的攻关，90年代全面展开。我的两位在沈阳的师兄个自有重任在肩。
风扇和匹配的低压涡轮得从新设计，新材料（粉末冶金，单晶叶片）新的合金，新的加工工艺（摩擦焊，电子束焊），新的计算方法，新的试验方法，新的试验台，中国的航空动力人，忙乎了将近二十年，把我们离世界先进水平的差距从35年缩短到20年。定型的太行基本达到了推比8的性能。
这期间，航发的全权数字控制系统（FADEC），先进的计算流体实验室（我的上铺兄弟是学术带头人），完备的试验体系，都是头一次建成。以后的发展就是加速度了。
有人说，美帝10年就可以开发出一个新型号，为什么我们要二十年？不要忘了，美帝代表的是人类目前为止技术的最高水平，他的齐备的工业体系，他在基本上所有子项目上独步全球的技术，使得他可以把他已有的技术整合一下，就可以拼出最好的产品。而我们，得攻关，在攻关，每一个子项目的攻关的失利，都会直接延迟整个项目的发展。
这就好比盖房子，人家是所有的PowerTool一应俱全，还主持制定了现有的建筑标准，也拥有所有房子里面子系统的最高技术（空调，材料，隔音等等），还领导着建筑界的新潮流。我们呢，才刚开始盖房子，木头也不好，工具也不行，建筑工人也是才是从农民转来的，更要命的是，我们得自己找到什么地方用什么料，用多少，都得从头摸索。怎么一个难字了得。
还记得小时候学习吗？是个加速度的过程，高中生一天学的内容，小学生一个月都学不完。
就是在这样的条件下，我们一步一步地赶上来了。我们离法国，俄国都没有质的差别了，赶上他们只是时间问题。我们离美国再也不是望着他们绝尘而去了，而是步步紧跟，总有追上的那一天。到底，领跑的也有他的难处，技术的发展也不是那么快的。
（三）之外篇：技术发展的关键是什么？
人才当然是技术发展中的一个重要因素，但只是必要条件之一吧。对于工业技术来说，一个强大的，持续的投入，就比人才更重要。甚至可以说是一个充分条件。说白了，就是要持续的往里砸钱。只要大方向正确，再有持续的投入，和型号上切合实际的要求，技术和人才都是可以培养出来的。
看看前苏联，大规模，持续的投入，就培养了队伍，人才，技术。解体后，没了投入，人才流失，技术停滞，队伍也就散了。我们80年代也散了一些队伍。
再看看中国航天，大方向正确，投钱，人才，技术，型号，10年工夫，都有了。
所以说，歼十和太行的意义远大于一个型号，通过它，储备了技术，培养了人才，行成了队伍。技术发展的延续性非常重要，东一榔头，西一棒子上发展不出好的技术的，就得靠多年持续的积累，厚积薄发啊。之所以叫太行，就是取在抗战中，TG在太行山区艰苦卓绝的斗争来纪念其研发过程之艰难。
前一阵，有人在感叹，说吴仲华先生如果文革每有被迫害，中国的发动机技术会如何如何，是混淆了工业技术发展和理论体系的发展。吴先生如果一直有好的条件，可能会对我们在流体力学的发展上做出更大的贡献，但是中国的工业基础，就是把他老人家累死，也不会有任何质的变化。
NASA每年巨额的经费，除去浪费的不说，带给美帝的是在航空航天领域独步全球的领先技术。
TG从来就没间断过从国外引进人次的努力，近年来，越来越多高层海龟的回流，也是一个因素。不过，在这些敏感领域，作基础研究的海外人才会的多些。真正做型号的，怕是本来就没有几个。局外人往往低估了美帝对我们的防范，美帝的保密制度，不亚于TG。设计具体的型号，那是要top level national security clearance的，要查祖宗三代，直系，旁系亲属，所有社会关系的。不是本土出生的，基本上很难进入这个圈子。李文和对于美帝，就是非我族类，其心必异的典型。我当年在 Georgia Tech Aerospace program, 系里组织参观Lockheed 在Marietta 生产F22 的工厂，所有学生，除了中国和俄罗斯的，都可以去。我的同学在NASA Lanley中心做研究员，也只能接触非常非常基础的研究，不可能涉及到型号，当然，NASA也没有型号任务，就是和型号相关的预研，也有不同等级的保密条例。
最终，还是得立足于国内，得靠自己。好在我们现在不太缺钱了，只要方向正确，技术突破就只是时间问题。
（四）昆仑，太行，秦岭的地位
用两弹一星的精神和投入来发展航空业，河里不是第一次提出来的。当年满腔热血的要为祖国的航空事业献身的我们，我们也知道我们的航空落后于世界，因为文革嘛，哪有不落后的呀。但当被告知我们的航空发动机技术落后美帝35年左右时，那份打击，那份透心凉，那份郁闷，至今栩栩如生。35年？我们90年才有美帝 55年的技术？我，我倒！
当时的国家主席，杨尚昆，白纸黑字的批示，“要象搞两弹一星一样的把我们的航空发动机搞上去”，想象一下，多让人激动。又有几个行业能得到国家主席如此的重视呢？后来系里的老教授在聊天时对此颇不以为然，我们当时还颇不理解，觉得这老先生有点不识抬举。后来果然，慢慢的就不提了。我们的航空，当然也是尽可能快地发展，但是不再是战略高度了。就是因为，两弹一星的方法不可复制在航发这样需要整体工业水平的提升的行业上的。
八十年代，我们的航发家底是：歼7用一台WP7，歼8用两台WP13，歼6和强5用两台WP6，轰6用两台WP8。
WP7我们算是基本吃透了，到底是50年代末的技术，我们多少也接触了一些新技术，觉得还有些可以改进的余地。提高推力和发动机热效率的一个办法，就是提高涡轮前温度，可是涡轮叶片要承受极大的应力和热载荷，有效地冷却技术和新材料是两个突破点。我们在叶片中心钻了9个小孔，从压气机引气冷却叶片。后来发现叶片根部有热应力集中的问题，会发展成裂纹。又改成3个不规则的大孔，直接用无余量的精密铸造成型。就这几句话，就是当年无数的攻关，计算，试验，花钱无穷，育人无数（我们实验室就有两个博士，5个硕士和这个有关）。
昆仑就是WP14，从立项到定型，也有15年时间。从性能上看，进步不大，为什么这么久呢？是因为我们从老大哥体系转到美帝体系的第一个型号，所有的设计标准，手册，试验台，试验方法和手段，都要而今迈步从头越。所以，外人看不到这些成果，可是这时实实在在的基础，对将来的研发是不可或缺的。
另外，WP14在寿命，可靠性，喘振裕度方面，都有质的提高。八爷在用两台WP14后，性能还是有长足的提升，和10，11可以形成有效搭配。
秦岭就是国产化的SPEY，当初因为载机下马，SPEY国产化的事也就搁下了。70年代末，80年代，军工只保证最低需求，没谱的SPEY，更是后娘的孩子。知道海航坚持要歼轰7，库存的50台原装SPEY不够用，才又开始国产化。不好意思的是，也是磕磕绊绊过来的国产SPEY，在寿命和性能上，和60年代末的原装货，还有一些差距。这就是我们的工业底子，这就是我们在材料，工艺上的差距。老牌帝国主义还是有些老底子的。顺便提一句，SPEY的厂商，就是 Rolls-Royles，香港人叫劳斯莱斯的，比房子都贵的车，也是他的一个分部生产的。
太行，是现在代表TG最高水平的小涵道涡扇。和毛子的AF-31基本上在一个级别，（AF-31在泼辣性上好，太行在寿命和经济性上略好）。可装一台给老十，或两台给老十一。
在研的还有太行的衍生型号。晨大有文详述，我就不班门弄斧了。
美帝的F-120和F-119都到了推比10一级，绝对的第一梯队。TG和毛子有现役的推比8一级的，算第二梯队。法国的阵风好像推比不到8，懒得查了。英国现在无力自主研发战机，所以军用发动机也就放下了，RR用民机的发动机来维持技术。其他国家，都数不上。
GE和普惠的在研军机，都是在推比20一级的，因为美帝觉得，新的材料（陶瓷，复合材料，etc）的发展瓶颈就要被突破了，可以大幅度的提高涡轮前温度和减轻机体重量。我们还得一步不落的跟，要不一不留神，美利坚同学就可能绝尘而去。
题外话，窃以为，我们这次金融危机还是站对了队的。美帝咒是咒不死的，不但咒不死，还很强大，还有活力。我们还得先把老二的位置好好坐坐稳，练好内功。如太宗预计，到2050年，我们的国民都过上和发达国家差不多的日子，我们就是想不出头，怕是世界人民都不答应。
Here goes the translation;
I - Introduction
There are many cutting edge technologies out there, such as rocketry, space science, nuclear power, semi-conductors, and many others, but why are these not considered to be the "cream of the crop" technology for modern industrial science?
Let's consider an analogy, a nation's heavy industry is like a pyramid, jet engines would be at the tip of the pyramid, because it involves all the aspects of today's modern science and all the best technologies a country can offer. In reality, the development of today's jet engines push forward society's whole industrial development.
Having said that, consider this, if one day our jet engine technology leaped ahead of the whole world, then we will be an undoubtedly a fucking solid superpower, and this cannot be disputed. Even if we are not as advanced as the Americans, as long as we can come shoulder to shoulder with them, then China's reemergence as and superpower will not be far.
Jet engine technology in general consists of metallurgy, material science, machining (机械加工, it literally means using machine to physically process something), machine manufacturing, thermo dynamics, aerodynamics, hydromechanics, machine automation/digitizing, and etc. Pretty much you can add up all the fields of applied sciences and jet engines would be associated with at least 75% of those fields.
Speaking of China's adoption of Su-27's production in the 90's and later the production of indigenous J-11, it made the Indians jealous, and they also wanted a production line. So the Russians thought who gives a damn which person is buying, as long as they pay, so they sent specialists to India to analyze the possibility of building such production line in India and where to place this facility. But after messing around for half a year, the experts advised India to start their industry all over again, from as basic as smelting, otherwise, there is no chance they will be able to do truly produce Su-27 other than just assembling imported Russian kits. (Therefore it is obvious to see the importance of Soviet aid to us in the 50's, it still all comes down to basics and a strong foundation is especially important (note, in the 50's Soviet Union sent tens of thousands of specialists and engineers into China to help with its industrial development)). In the 80's, Pakistan imported F-16's, so we took one over to study it. But due the limitations in our industrial capability, even if we had the whole set of blueprints; we would still not be able to fully produce this jet. Unless the Yankees did the same thing to us as the Soviets did in the 50's. Back in the 80's, we don't even have the materials to build at least half of the parts in the F-16, not mentioning the technology to manufacture it. Even today, we might still be inferior in terms of metallurgy (material science) and manufacturing skills. This is unfortunate, since it cannot be dealt with in short periods; it takes time to build up experience.
Speaking of this, reminds me of a story, back in the days during the project 863, the Department of Aeronautic Material Science had a crucial research project to tackle the techniques needed to manufacture turbine discs using metal powder. It is done by putting specially mixed (the ratio is top secret for all countries) metal powder into a mold and then treat it with high temperature and pressure, it turns into a turbine disc. This kind of turbine disc has a very good crystal arrangement (almost all stressed parts used in jet engines are some sort of crystallized metal) and it's able to stand high temperature and high pressure; in fact the disc in F404 is manufactured this way. So we attempted to do it like how the Americans did it. The whole project cost around 350mil, it wasn't bad and we were successful. There were lots of parties celebrating this achievement, but then another problem came, we didn't have the blades strong enough to cut it. The whole cutting process had to be done in one continuous motion, there cannot be stops to replace the blade, or else uneven cuts will cause the disc to crack during flight. So we had to tackle another problem with a new project.
So our expertise in jet engine technology is like an old beer barrel, every plank is faulty. (Chinese culture uses analogy of the beer barrel; similar to the saying “we are as strong as the weakest link”) We had to fix every faulty plank to make it work.
II – The Awkward Situation
Our knowledge of jet engine technology was like a blank paper prior to the founding of the republic. We initially learnt how to fix imported Soviet engines during the Korean War. Then later the “156 aid projects” to us from the Soviet became the most drastic and thorough industrialization in human history. The factory I spent the summer in during my co-op in Shenyang was part of the project 156.
At that time, in less than 10 years, on surface (note, on surface), we caught up to world leading powers in terms of jet engine technology. In the beginning of the 60’s, we successfully copied the Mig-21 and its turbojet engine, it made us first tier in jet engine field.
However, as soon as the Sino-Soviet split happened, we were lost. Any attempted changes to the original engine design sparked countless unknown domino effects, then the later cultural revolution, it took us 20 years to thoroughly grasp and understand Mig-21’s engine, and later successfully produced improved variants. J-7G is known as the best redesigned Mig-21 in the world, unfortunately, it took us whole 20 years to do it.
Even in the tightly locked 60’s and 70’s, Red China never stopped attempting to acquire edvanced technologies. Two squadrons of J-6 were shipped to Egypt to trade for a Mig23, then from Mig23’s engine, we designed the WP15, which is still the most powerful turbojet in China, but due to no suitable planes to fit this engine, it was dropped. Later China spent a lot of money to import the SPEY production line, this made Xi’an 430 bureau the most advanced factory under the 3rd Industry department (Soviet industrial craftsmanship were inferior to the British). The SPEY was also dropped, but the WP15 and SPEY taught us a lot new technologies and crafting techniques.
Then in the 70’s, due to the rapprochement, the Americans let us buy their technologies, all of these technologies looked fancy, and all cost a lot, we didn’t even know where to start, partially because we were too poor.
Later due to the Tian’an’men incident, half way through the Peace Pearl project (Northrop helped to upgrade J-8), the Americans flipped the card. The project was busted but we learned value lessons, such as American design standard, design styles, later the guidelines and manuals printed by the Aeronautic Department was literally the translated version of the American counterpart.
Apart from the military projects, we also had other attempts. During the honeymoon period, the civil aviation bought a batch of 737’s for its CFM56; its core is pretty much GE’s F100, the engine on the F15. The core in a jet engine is composed of high pressure compressor, burning chamber, high pressure fans (aka gas generator cycle). All these are modularly designed, and can be fitted with different outer blades and lower pressure compressor to create new variants. In the beginning, the American government the Pentagon was very against such deal, but Boeing had done a hell of a job lobbying and greasing all the parties. Their argument was that the idea of not selling spare engine with new aircraft is obscured. It was finally approved by the congress and signed by the president.
But there was a pre-condition, it was sealed in a box with special seals, and had to be examined by the American specialists every 6 months, to make sure the Chinese don’t get to look deep into the engine. (Remember the Hughes Satellite? It was guarded 24/7’s by 3 CIA agents prior to its launch.)
Unsurprisingly, it was unboxed, shipped to Shenyang, measured, surveyed, modeled, reassembled, and then shipped back to Beijing, and resealed, all done within 5 months period.
II – Extrinsic Chapter – Yankees pissed off
Again, it is obvious that such a large project this scale cannot be undetected for too long. But initially, it was funny that the Americans had no evidence and China just played dumb, just pretended nothing happened. But one day, American officials showed a duplicated copy of a highly classified Chinese government document titled, “policies on survey of CFM56 core”. I personally heard a rumor saying it was the Shenyang 606 bureau chief’s son, incompetent in life, but didn’t want to stay as no body. He heard about this project from his father, one day he stole the keys and got hold of the document, later turned it to the American embassy and wanted American citizenship in return. The news was heard by Jiang Zeming, and in anger, he ordered the young be killed. Three months later, a man died in car crash. Of course, this is all urban legend, especially in today’s day and age, where rumors even make to credible media, you can never believe it.
III – Taihang, Fruition
A lot people say, is it really that hard to copy someone else’s homework? It is, especially to fully understand it and then reapply the knowledge to another question. The Chinese aerospace industry is like a redneck take lecture at MIT, can’t understand a damn thing, he had to go home and dig out all the books as far back as middle school and restudy everything.
But then many people ask, why the Soviets/Russian and American don’t have a high guard for the Indians? That’s because he doesn’t have a good foundation and like to slack off, even if you give him the answers, and with help of tutors, he still won’t be able to copy. From J6 to Q5, Mig21 to J7, J8, J11, J10, China did all these on its own. Aerospace industry cannot simply be copied, it takes time and effort. You cannot simply take someone else’s work and instantly become a leading competitor.
Therefore, the core from CFM56 only acted as a rough guide, it had to be thoroughly studied. In fact, my undergrad thesis/project was on CFM56’s blade stress during flight (not sure if he’s BSing, an undergrad probably can’t work on something this high-level, he was probably an assistant to his professor, if he participated at all).
From blade to low pressure fans, to new materials, new alloys, new manufacturing techniques (fiction welding, plasma welding), new computational techniques, new experimenting techniques, new testing platforms, it took us nearly 20 years to shorten the gaps from 35 years to 20 years we have with the West. The finalized Taihang reached thrust to weight ratio of 8.
During this period, jet engine’s FADEC (fully automatic digital electronic control system), advanced fluid dynamic computation laboratory (my former dorm-mate was head of this laboratory) and other related subsystems and sub-projects were set up. Now a comprehensive research system set up for the very first time. The only thing to do after this is to accelerate the research.
Many ask why it only takes the American 10 years to do a new design, and us taking 20 years. Don’t forget, the Americans are at the pinnacle of technology, they have a very comprehensive supporting network and highly developed heavy industry. Most of their basic researches were done and subsystems matured even before a new weapon/vehicle is proposed. All they have to do is to integrate those technologies like Lego’s. But for us, we propose a new weapon first, then we find out where we lack in technologies, every problem had to be tackled individually; often the whole problem had to wait for a small bottleneck to move on. In another word, it is pretty much like building a house; the Americans already have all the tools ready and a readymade blueprint, also all the subsystems are pre-purchased, like toilets, fences, windows, and etc. But for us, we just started building house for the very first time, we have no blueprint and no good materials, everything had to be figured out as we move along.
Sorry, too tired and sleepy, ill finish the rest tomorrow.
Here is the original text I have read on an oversea Chinese website. I know it's long and contain a lot of information, so I'll try my best to translate this as detailed as my time allow me.
Note that there are a lot of languages used in this post are slangs and idioms unique to Chinese culture and language, so I will change it a bit so that everyone here can understand it. Also note that I have left China since I was 10 years old, so if any other Chinese friends see me making stupid mistakes, please just forgive me and let me know that I have done something wrong.
关于中国航空发动机领域一些鲜为人知的事情
高科技，尖端科技多了，为什么航空发动机是工业之花？空间技术，火箭技术，核电技术，微电子技术，都有各自的特点和难点，为什么他们不是工业之花？
我们来做个比喻，整个国家的第二产业（从冶金到制造到加工，设计）是一个金字塔，航发就是这个金字塔的塔尖，它涉及到了基本上所有的工业和技术项目，并且要用到这些领域的最高技术成就。其实，使航发技术的发展，在带动着整个工业的进步。
说到这里，想象一下，如果我们的航空发动机技术有一天独步全球，那我们就TMD是不折不扣的超级大国，想不承认都不行。甚至都不必象美国人一样领先，只要我们在技术上和他们平起平坐，中华民族的复兴之梦就算是跑不了了。
航发技术从大面上说，涉及到：冶金，材料，机械加工，机械制造，热力学，空气动力学，流体力学，控制学，等等等等吧，基本上吧，你把工科的学科统统算上，75％以上都要把自己的最高成就献给航发。
话说九十年代中国引进Su27生产线后，自己的J-11开始批量生产。三哥眼红了，也想要一条生产线。毛子心说，卖给谁不是卖，给钱就行，于是派专家组考察三哥的工业设施，考虑在那儿设接收点。折腾了半年，专家组的意见是，三哥现有的工业得从冶金开始，重新来过，二十年之内，不可能自己生产。（由此可见，五十年代老大哥对我们的援助是多么的重要，基础，基础啊）
八十年代，小巴装备了F-16，我们也搞过来了一架，看看还是有点帮助吧，也就仅限于此了。我们当年的工业基础，就是有全套的技术资料，也造不出来呀。除非象和老美当年蜜月期的计划一样，由美国整体援建配套工厂。当年，F-16上，怕是有一半以上的零件，我们连材料都没有，更别提加工工艺了。即便是今天，我们可能也还是有些材料和工艺上的差距。没办法呀，底子薄啊。班上学习好的，还就是几个老牌资本主义强国，工业上的差距，真的得多年的修行才可以有正果的。
说到这里，讲个小故事，当年863计划，航空部材料所有一项，粉末冶金涡轮盘。就是把金属粉末，按比例（呵呵，这个比例可是国之机密）放在容器里，高温高压下，变成合金。具有很好的结晶顺序，可以耐高温，强度也好。F404上的高压涡轮盘就是这样的，咱们就照着葫芦画瓢吧。整个项目3.5亿RMB，还不错，搞定了，大大小小的庆功会也开了不少。新材料有了，咱们也来一盘？上车床，从盘心到盘边，F404是一刀走到底，这样保证没有因为换刀时产生的痕迹，（将来就是裂纹的萌芽），可是问题是，我们的车刀的材料不行，一刀走不完，就磨没了，得换刀。这下才发现，我们还得要另一个攻关项目。
所以，我们的水桶，每一块板都不够长，这个水桶就是我们的工业能力，我们正在集中力量，加高每一块板，尤其是那些相对更短的板。两弹一星只是一个相对独立的项目，可以集中力量办大事，（即便是这样，也有很多土法上马的例子）。而整个工业能力的提升，又怎样集中力量办大事哪？
（二）尴尬时期
我们的航空发动机，建国前，是空白，比白纸还白，一穷二白。五十年代从朝鲜战争起，开始修发动机，战后，由于我们志愿军将士的英勇牺牲，我们在老大哥那里，基本上属于有栽培潜力的了。
随后的156个项目，是人类历史上最激烈，最彻底的工业化。沈阳的黎明厂(有幸在那实习了一个夏天，沈阳的狗肉和试车的轰鸣，一起记录在我们青春的回忆中) 就是156之一。
不到十年，我们就在表面上（注意，是表面上）赶上了世界先进水平。60年代初的Mig21仿制成功，我们在涡喷发动机上也拥有了双转子轴流式涡喷的先进水平。
可是，知其然不知其所以然。老大哥一撒手，我们就抓了瞎。对于原设计的任何改动，都会引发多米诺骨牌式的连锁反应。加上文革的折腾，我们用了20年，才在 80年代初，成功地吃透了MIG21和涡喷7的技术，并推出了成功的改进型号。歼7G被誉为世界上改的最好的MIG21。可惜晚了二十年。
即便是在被封锁的最严的60，70 年代，TG从来没有放弃引进技术。两个中队的歼6从埃及换来了MIG23，从MIG23上仿制的WP15至今是TG最大推力的涡喷，只是一直没有合适的机型。花巨额外汇（当年）引进的斯贝生产线，使得西安的430一直是三机部加工工艺最好的工厂。（老大哥当年的工艺就不如约翰牛）Spey也是没有装机。但是，WP15和Spey都给了我们很多启发和具体技术，工艺上的提升。
隔壁小胖的作业早就抄不上了，我们在70年代末和班上最优秀的同学结成了一对一，一对红，美利坚同学的作业让人眼花缭乱，每道题又要花大价钱才给抄，一时半会不知道先抄那道题好。（NND，咱穷啊）
到了风波的春夏之交，我们一道和平典范的题才抄了半，老美翻脸了，把我们的作业本都扣了。但我们好歹还是瞄了两眼，大体知道了他的解题思路（美军标，设计规范，航空部后来颁发的设计标准，简直就是美军标的翻译版。）
TG野路子走惯了，从来不按牌理出牌。在蜜月期，也没有闲着搞小动作。民航买了一批737，装CFM56，其核心机就是GE的F100（两台装F-15）的核心机。核心机就是高压压气机，燃烧室，高压涡轮组成的，又叫燃气发生器。都模块化后，可以和外围的风扇，低压压气机组成一个系列的型号。这个 CFM56买的，也是我们摆事实，讲道理，美国国会和巴统特批的。批之前，就有人说，TG要是偷我们的技术怎么办，blah, blah. 可是哪有卖飞机不给卖备用发动机的？波音的游说集团，我们朋友大大的。
这批发动机，封在箱子里，美方每半年来查一次。（NND，记得休斯公司的卫星吗，3个CIA24小时日夜监守，最终也没能下的去手），这，能难得住我们英雄的中国人民吗？
拆箱，编号，直运沈阳，测绘，建模，组装，运回北京，上封条， 不到五个月，搞定。
（二）之外篇·发动机书场·美帝兴师问罪
这么大的项目，不知道才怪了，人家的情报部门也不是吃干饭的。但是，他没有证据，没有，没有，就是没有，你看见了？国家间，往往也就是幼儿园的交际水平。
知道有一天，美帝拿着咱航空部的红头文件来兴师问罪了，文件的标题是“关于做好CFM56核心机测绘工作的指示”，我，我倒！这是谁干的！
我当是谣言听来的，您也就当时说书的听吧。沈阳606所的一个处长的儿子，不长进，但还有点想
法，不甘于过一般小混混的生活。他知道我们当时有重点型号，和美帝有关，就留了心眼儿，有一天，偷了他爹的钥匙，找了这份文件，直接就上了领事馆，要求避难。
可以想象，TG当时还是很被动的，尤其是90年代，还处在想和人修复关系的阶段，记得朱总的消气之旅吗？要搁现在，老子就是做了，你怎么着吧？具体怎么把这事私了了，就不是我所能知道的了。总之，惊动了江总，江总很生气，后果很严重。总书记亲笔批示，“要让叛国者心惊胆颤”，三个月后，美国中部小城市，车祸，一中年男子当场死亡。
（三）太行，修成正果
那位说了，切，抄个作业还这样费劲。这您就是外行了，要抄到知其然，还知其所以然，要抄到下一道题，老子我自己会做了，就不光是抄答案了，得一边抄，一边琢磨人家的解题思路，更得补以前没学过的知识。TG就象一个天赋不错的工农兵大学生，高数课上听不懂，抄作业过关，可回家就把初中，高中的课本全翻出来，恶补啊。
为什么美苏都不设防三哥？就他那点基础，还不用功，给他抄，给他把家教请来都不灵。歼6到强5，MIG21 到歼7G，歼8，Su27到歼11，TG从来就不是甘心居人篱下的主。借用虎哥一句话，只要我们自己不崩溃，成圣是早晚的事。我们要考虑的是，成圣之后，如何防止历史的循环，坠入英帝，美帝的宿命。太祖在西柏坡是怎么说的？
扯远了。
所以，CFM56 也只是给了TG一个大致的方向。整个核心机的尺寸，一模一样。小子不才，本科毕设的题目就是10A的所有叶片的动力相应分析。所有分析，计算，试验，材料，工艺的攻关，90年代全面展开。我的两位在沈阳的师兄个自有重任在肩。
风扇和匹配的低压涡轮得从新设计，新材料（粉末冶金，单晶叶片）新的合金，新的加工工艺（摩擦焊，电子束焊），新的计算方法，新的试验方法，新的试验台，中国的航空动力人，忙乎了将近二十年，把我们离世界先进水平的差距从35年缩短到20年。定型的太行基本达到了推比8的性能。
这期间，航发的全权数字控制系统（FADEC），先进的计算流体实验室（我的上铺兄弟是学术带头人），完备的试验体系，都是头一次建成。以后的发展就是加速度了。
有人说，美帝10年就可以开发出一个新型号，为什么我们要二十年？不要忘了，美帝代表的是人类目前为止技术的最高水平，他的齐备的工业体系，他在基本上所有子项目上独步全球的技术，使得他可以把他已有的技术整合一下，就可以拼出最好的产品。而我们，得攻关，在攻关，每一个子项目的攻关的失利，都会直接延迟整个项目的发展。
这就好比盖房子，人家是所有的PowerTool一应俱全，还主持制定了现有的建筑标准，也拥有所有房子里面子系统的最高技术（空调，材料，隔音等等），还领导着建筑界的新潮流。我们呢，才刚开始盖房子，木头也不好，工具也不行，建筑工人也是才是从农民转来的，更要命的是，我们得自己找到什么地方用什么料，用多少，都得从头摸索。怎么一个难字了得。
还记得小时候学习吗？是个加速度的过程，高中生一天学的内容，小学生一个月都学不完。
就是在这样的条件下，我们一步一步地赶上来了。我们离法国，俄国都没有质的差别了，赶上他们只是时间问题。我们离美国再也不是望着他们绝尘而去了，而是步步紧跟，总有追上的那一天。到底，领跑的也有他的难处，技术的发展也不是那么快的。
（三）之外篇：技术发展的关键是什么？
人才当然是技术发展中的一个重要因素，但只是必要条件之一吧。对于工业技术来说，一个强大的，持续的投入，就比人才更重要。甚至可以说是一个充分条件。说白了，就是要持续的往里砸钱。只要大方向正确，再有持续的投入，和型号上切合实际的要求，技术和人才都是可以培养出来的。
看看前苏联，大规模，持续的投入，就培养了队伍，人才，技术。解体后，没了投入，人才流失，技术停滞，队伍也就散了。我们80年代也散了一些队伍。
再看看中国航天，大方向正确，投钱，人才，技术，型号，10年工夫，都有了。
所以说，歼十和太行的意义远大于一个型号，通过它，储备了技术，培养了人才，行成了队伍。技术发展的延续性非常重要，东一榔头，西一棒子上发展不出好的技术的，就得靠多年持续的积累，厚积薄发啊。之所以叫太行，就是取在抗战中，TG在太行山区艰苦卓绝的斗争来纪念其研发过程之艰难。
前一阵，有人在感叹，说吴仲华先生如果文革每有被迫害，中国的发动机技术会如何如何，是混淆了工业技术发展和理论体系的发展。吴先生如果一直有好的条件，可能会对我们在流体力学的发展上做出更大的贡献，但是中国的工业基础，就是把他老人家累死，也不会有任何质的变化。
NASA每年巨额的经费，除去浪费的不说，带给美帝的是在航空航天领域独步全球的领先技术。
TG从来就没间断过从国外引进人次的努力，近年来，越来越多高层海龟的回流，也是一个因素。不过，在这些敏感领域，作基础研究的海外人才会的多些。真正做型号的，怕是本来就没有几个。局外人往往低估了美帝对我们的防范，美帝的保密制度，不亚于TG。设计具体的型号，那是要top level national security clearance的，要查祖宗三代，直系，旁系亲属，所有社会关系的。不是本土出生的，基本上很难进入这个圈子。李文和对于美帝，就是非我族类，其心必异的典型。我当年在 Georgia Tech Aerospace program, 系里组织参观Lockheed 在Marietta 生产F22 的工厂，所有学生，除了中国和俄罗斯的，都可以去。我的同学在NASA Lanley中心做研究员，也只能接触非常非常基础的研究，不可能涉及到型号，当然，NASA也没有型号任务，就是和型号相关的预研，也有不同等级的保密条例。
最终，还是得立足于国内，得靠自己。好在我们现在不太缺钱了，只要方向正确，技术突破就只是时间问题。
（四）昆仑，太行，秦岭的地位
用两弹一星的精神和投入来发展航空业，河里不是第一次提出来的。当年满腔热血的要为祖国的航空事业献身的我们，我们也知道我们的航空落后于世界，因为文革嘛，哪有不落后的呀。但当被告知我们的航空发动机技术落后美帝35年左右时，那份打击，那份透心凉，那份郁闷，至今栩栩如生。35年？我们90年才有美帝 55年的技术？我，我倒！
当时的国家主席，杨尚昆，白纸黑字的批示，“要象搞两弹一星一样的把我们的航空发动机搞上去”，想象一下，多让人激动。又有几个行业能得到国家主席如此的重视呢？后来系里的老教授在聊天时对此颇不以为然，我们当时还颇不理解，觉得这老先生有点不识抬举。后来果然，慢慢的就不提了。我们的航空，当然也是尽可能快地发展，但是不再是战略高度了。就是因为，两弹一星的方法不可复制在航发这样需要整体工业水平的提升的行业上的。
八十年代，我们的航发家底是：歼7用一台WP7，歼8用两台WP13，歼6和强5用两台WP6，轰6用两台WP8。
WP7我们算是基本吃透了，到底是50年代末的技术，我们多少也接触了一些新技术，觉得还有些可以改进的余地。提高推力和发动机热效率的一个办法，就是提高涡轮前温度，可是涡轮叶片要承受极大的应力和热载荷，有效地冷却技术和新材料是两个突破点。我们在叶片中心钻了9个小孔，从压气机引气冷却叶片。后来发现叶片根部有热应力集中的问题，会发展成裂纹。又改成3个不规则的大孔，直接用无余量的精密铸造成型。就这几句话，就是当年无数的攻关，计算，试验，花钱无穷，育人无数（我们实验室就有两个博士，5个硕士和这个有关）。
昆仑就是WP14，从立项到定型，也有15年时间。从性能上看，进步不大，为什么这么久呢？是因为我们从老大哥体系转到美帝体系的第一个型号，所有的设计标准，手册，试验台，试验方法和手段，都要而今迈步从头越。所以，外人看不到这些成果，可是这时实实在在的基础，对将来的研发是不可或缺的。
另外，WP14在寿命，可靠性，喘振裕度方面，都有质的提高。八爷在用两台WP14后，性能还是有长足的提升，和10，11可以形成有效搭配。
秦岭就是国产化的SPEY，当初因为载机下马，SPEY国产化的事也就搁下了。70年代末，80年代，军工只保证最低需求，没谱的SPEY，更是后娘的孩子。知道海航坚持要歼轰7，库存的50台原装SPEY不够用，才又开始国产化。不好意思的是，也是磕磕绊绊过来的国产SPEY，在寿命和性能上，和60年代末的原装货，还有一些差距。这就是我们的工业底子，这就是我们在材料，工艺上的差距。老牌帝国主义还是有些老底子的。顺便提一句，SPEY的厂商，就是 Rolls-Royles，香港人叫劳斯莱斯的，比房子都贵的车，也是他的一个分部生产的。
太行，是现在代表TG最高水平的小涵道涡扇。和毛子的AF-31基本上在一个级别，（AF-31在泼辣性上好，太行在寿命和经济性上略好）。可装一台给老十，或两台给老十一。
在研的还有太行的衍生型号。晨大有文详述，我就不班门弄斧了。
美帝的F-120和F-119都到了推比10一级，绝对的第一梯队。TG和毛子有现役的推比8一级的，算第二梯队。法国的阵风好像推比不到8，懒得查了。英国现在无力自主研发战机，所以军用发动机也就放下了，RR用民机的发动机来维持技术。其他国家，都数不上。
GE和普惠的在研军机，都是在推比20一级的，因为美帝觉得，新的材料（陶瓷，复合材料，etc）的发展瓶颈就要被突破了，可以大幅度的提高涡轮前温度和减轻机体重量。我们还得一步不落的跟，要不一不留神，美利坚同学就可能绝尘而去。
题外话，窃以为，我们这次金融危机还是站对了队的。美帝咒是咒不死的，不但咒不死，还很强大，还有活力。我们还得先把老二的位置好好坐坐稳，练好内功。如太宗预计，到2050年，我们的国民都过上和发达国家差不多的日子，我们就是想不出头，怕是世界人民都不答应。
Here goes the translation;
I - Introduction
There are many cutting edge technologies out there, such as rocketry, space science, nuclear power, semi-conductors, and many others, but why are these not considered to be the "cream of the crop" technology for modern industrial science?
Let's consider an analogy, a nation's heavy industry is like a pyramid, jet engines would be at the tip of the pyramid, because it involves all the aspects of today's modern science and all the best technologies a country can offer. In reality, the development of today's jet engines push forward society's whole industrial development.
Having said that, consider this, if one day our jet engine technology leaped ahead of the whole world, then we will be an undoubtedly a fucking solid superpower, and this cannot be disputed. Even if we are not as advanced as the Americans, as long as we can come shoulder to shoulder with them, then China's reemergence as and superpower will not be far.
Jet engine technology in general consists of metallurgy, material science, machining (机械加工, it literally means using machine to physically process something), machine manufacturing, thermo dynamics, aerodynamics, hydromechanics, machine automation/digitizing, and etc. Pretty much you can add up all the fields of applied sciences and jet engines would be associated with at least 75% of those fields.
Speaking of China's adoption of Su-27's production in the 90's and later the production of indigenous J-11, it made the Indians jealous, and they also wanted a production line. So the Russians thought who gives a damn which person is buying, as long as they pay, so they sent specialists to India to analyze the possibility of building such production line in India and where to place this facility. But after messing around for half a year, the experts advised India to start their industry all over again, from as basic as smelting, otherwise, there is no chance they will be able to do truly produce Su-27 other than just assembling imported Russian kits. (Therefore it is obvious to see the importance of Soviet aid to us in the 50's, it still all comes down to basics and a strong foundation is especially important (note, in the 50's Soviet Union sent tens of thousands of specialists and engineers into China to help with its industrial development)). In the 80's, Pakistan imported F-16's, so we took one over to study it. But due the limitations in our industrial capability, even if we had the whole set of blueprints; we would still not be able to fully produce this jet. Unless the Yankees did the same thing to us as the Soviets did in the 50's. Back in the 80's, we don't even have the materials to build at least half of the parts in the F-16, not mentioning the technology to manufacture it. Even today, we might still be inferior in terms of metallurgy (material science) and manufacturing skills. This is unfortunate, since it cannot be dealt with in short periods; it takes time to build up experience.
Speaking of this, reminds me of a story, back in the days during the project 863, the Department of Aeronautic Material Science had a crucial research project to tackle the techniques needed to manufacture turbine discs using metal powder. It is done by putting specially mixed (the ratio is top secret for all countries) metal powder into a mold and then treat it with high temperature and pressure, it turns into a turbine disc. This kind of turbine disc has a very good crystal arrangement (almost all stressed parts used in jet engines are some sort of crystallized metal) and it's able to stand high temperature and high pressure; in fact the disc in F404 is manufactured this way. So we attempted to do it like how the Americans did it. The whole project cost around 350mil, it wasn't bad and we were successful. There were lots of parties celebrating this achievement, but then another problem came, we didn't have the blades strong enough to cut it. The whole cutting process had to be done in one continuous motion, there cannot be stops to replace the blade, or else uneven cuts will cause the disc to crack during flight. So we had to tackle another problem with a new project.
So our expertise in jet engine technology is like an old beer barrel, every plank is faulty. (Chinese culture uses analogy of the beer barrel; similar to the saying “we are as strong as the weakest link”) We had to fix every faulty plank to make it work.
II – The Awkward Situation
Our knowledge of jet engine technology was like a blank paper prior to the founding of the republic. We initially learnt how to fix imported Soviet engines during the Korean War. Then later the “156 aid projects” to us from the Soviet became the most drastic and thorough industrialization in human history. The factory I spent the summer in during my co-op in Shenyang was part of the project 156.
At that time, in less than 10 years, on surface (note, on surface), we caught up to world leading powers in terms of jet engine technology. In the beginning of the 60’s, we successfully copied the Mig-21 and its turbojet engine, it made us first tier in jet engine field.
However, as soon as the Sino-Soviet split happened, we were lost. Any attempted changes to the original engine design sparked countless unknown domino effects, then the later cultural revolution, it took us 20 years to thoroughly grasp and understand Mig-21’s engine, and later successfully produced improved variants. J-7G is known as the best redesigned Mig-21 in the world, unfortunately, it took us whole 20 years to do it.
Even in the tightly locked 60’s and 70’s, Red China never stopped attempting to acquire edvanced technologies. Two squadrons of J-6 were shipped to Egypt to trade for a Mig23, then from Mig23’s engine, we designed the WP15, which is still the most powerful turbojet in China, but due to no suitable planes to fit this engine, it was dropped. Later China spent a lot of money to import the SPEY production line, this made Xi’an 430 bureau the most advanced factory under the 3rd Industry department (Soviet industrial craftsmanship were inferior to the British). The SPEY was also dropped, but the WP15 and SPEY taught us a lot new technologies and crafting techniques.
Then in the 70’s, due to the rapprochement, the Americans let us buy their technologies, all of these technologies looked fancy, and all cost a lot, we didn’t even know where to start, partially because we were too poor.
Later due to the Tian’an’men incident, half way through the Peace Pearl project (Northrop helped to upgrade J-8), the Americans flipped the card. The project was busted but we learned value lessons, such as American design standard, design styles, later the guidelines and manuals printed by the Aeronautic Department was literally the translated version of the American counterpart.
Apart from the military projects, we also had other attempts. During the honeymoon period, the civil aviation bought a batch of 737’s for its CFM56; its core is pretty much GE’s F100, the engine on the F15. The core in a jet engine is composed of high pressure compressor, burning chamber, high pressure fans (aka gas generator cycle). All these are modularly designed, and can be fitted with different outer blades and lower pressure compressor to create new variants. In the beginning, the American government the Pentagon was very against such deal, but Boeing had done a hell of a job lobbying and greasing all the parties. Their argument was that the idea of not selling spare engine with new aircraft is obscured. It was finally approved by the congress and signed by the president.
But there was a pre-condition, it was sealed in a box with special seals, and had to be examined by the American specialists every 6 months, to make sure the Chinese don’t get to look deep into the engine. (Remember the Hughes Satellite? It was guarded 24/7’s by 3 CIA agents prior to its launch.)
Unsurprisingly, it was unboxed, shipped to Shenyang, measured, surveyed, modeled, reassembled, and then shipped back to Beijing, and resealed, all done within 5 months period.
II – Extrinsic Chapter – Yankees pissed off
Again, it is obvious that such a large project this scale cannot be undetected for too long. But initially, it was funny that the Americans had no evidence and China just played dumb, just pretended nothing happened. But one day, American officials showed a duplicated copy of a highly classified Chinese government document titled, “policies on survey of CFM56 core”. I personally heard a rumor saying it was the Shenyang 606 bureau chief’s son, incompetent in life, but didn’t want to stay as no body. He heard about this project from his father, one day he stole the keys and got hold of the document, later turned it to the American embassy and wanted American citizenship in return. The news was heard by Jiang Zeming, and in anger, he ordered the young be killed. Three months later, a man died in car crash. Of course, this is all urban legend, especially in today’s day and age, where rumors even make to credible media, you can never believe it.
III – Taihang, Fruition
A lot people say, is it really that hard to copy someone else’s homework? It is, especially to fully understand it and then reapply the knowledge to another question. The Chinese aerospace industry is like a redneck take lecture at MIT, can’t understand a damn thing, he had to go home and dig out all the books as far back as middle school and restudy everything.
But then many people ask, why the Soviets/Russian and American don’t have a high guard for the Indians? That’s because he doesn’t have a good foundation and like to slack off, even if you give him the answers, and with help of tutors, he still won’t be able to copy. From J6 to Q5, Mig21 to J7, J8, J11, J10, China did all these on its own. Aerospace industry cannot simply be copied, it takes time and effort. You cannot simply take someone else’s work and instantly become a leading competitor.
Therefore, the core from CFM56 only acted as a rough guide, it had to be thoroughly studied. In fact, my undergrad thesis/project was on CFM56’s blade stress during flight (not sure if he’s BSing, an undergrad probably can’t work on something this high-level, he was probably an assistant to his professor, if he participated at all).
From blade to low pressure fans, to new materials, new alloys, new manufacturing techniques (fiction welding, plasma welding), new computational techniques, new experimenting techniques, new testing platforms, it took us nearly 20 years to shorten the gaps from 35 years to 20 years we have with the West. The finalized Taihang reached thrust to weight ratio of 8.
During this period, jet engine’s FADEC (fully automatic digital electronic control system), advanced fluid dynamic computation laboratory (my former dorm-mate was head of this laboratory) and other related subsystems and sub-projects were set up. Now a comprehensive research system set up for the very first time. The only thing to do after this is to accelerate the research.
Many ask why it only takes the American 10 years to do a new design, and us taking 20 years. Don’t forget, the Americans are at the pinnacle of technology, they have a very comprehensive supporting network and highly developed heavy industry. Most of their basic researches were done and subsystems matured even before a new weapon/vehicle is proposed. All they have to do is to integrate those technologies like Lego’s. But for us, we propose a new weapon first, then we find out where we lack in technologies, every problem had to be tackled individually; often the whole problem had to wait for a small bottleneck to move on. In another word, it is pretty much like building a house; the Americans already have all the tools ready and a readymade blueprint, also all the subsystems are pre-purchased, like toilets, fences, windows, and etc. But for us, we just started building house for the very first time, we have no blueprint and no good materials, everything had to be figured out as we move along.
Sorry, too tired and sleepy, ill finish the rest tomorrow.
Hendrik_2000
Lieutenant General
Re: The UNKNOWN History of Chinese Jet Engines
Wow it is interesting. That is why it takes so long I also believe building jet engine is the pinnacle of one country technology. Thanks for sharing this article
Wow it is interesting. That is why it takes so long I also believe building jet engine is the pinnacle of one country technology. Thanks for sharing this article
Re: The UNKNOWN History of Chinese Jet Engines
This looks like a pretty good translation. Just two points.
In the next sentence for "fan" read "turbine":
The core in a jet engine is composed of high pressure compressor, burning chamber, high pressure fans (aka gas generator cycle)
And here I miss a single "r", "friction", nor "fiction":
(fiction welding, plasma welding)
Of course based on my knowledge of aircraft engines. I don't no Chinese.
This looks like a pretty good translation. Just two points.
In the next sentence for "fan" read "turbine":
The core in a jet engine is composed of high pressure compressor, burning chamber, high pressure fans (aka gas generator cycle)
And here I miss a single "r", "friction", nor "fiction":
(fiction welding, plasma welding)
Of course based on my knowledge of aircraft engines. I don't no Chinese.
pugachev_diver
Banned Idiot
Re: The UNKNOWN History of Chinese Jet Engines
here's a descriptive diagram of a modern turbofan
Animation of a 2-spool, high-bypass turbofan.
A. Low pressure spool
B. High pressure spool
C. Stationary components
1. Nacelle
2. Fan
3. Low pressure compressor
4. High pressure compressor
5. Combustion chamber
6. High pressure turbine
7. Low pressure turbine
8. Core nozzle
9. Fan nozzle
here's a descriptive diagram of a modern turbofan
Animation of a 2-spool, high-bypass turbofan.
A. Low pressure spool
B. High pressure spool
C. Stationary components
1. Nacelle
2. Fan
3. Low pressure compressor
4. High pressure compressor
5. Combustion chamber
6. High pressure turbine
7. Low pressure turbine
8. Core nozzle
9. Fan nozzle