Chapter 1016 SeA650 engine, final assembly completed!


    After hearing this statement, Wu Wei''s eyes showed a clear look of confusion.


    ?However, after today''s mental journey of ups and downs, his mentality at this moment has been tempered to be as solid as a rock.


    Therefore, even though he didn''t understand it at all, he still didn''t show it and just waited for Chang Haonan''s further explanation.


    After all, the latter has just mentioned that changes at the hardware level will be involved, and in the end it will have to be implemented by their 54th office.


    Sure enough, after a brief thought, Chang Haonan spoke again:


    "Theoretically, as long as the mapping relationship between the superimposed waveform and the information can be established, the superimposed waveform can be directly demodulated without the need to demodulate each user''s information individually... It only needs to perform a one-step XOR operation to eliminate The self-interference caused by the broadcast effect will not add too much additional computing power and power consumption burden to the system.”


    “In addition, to complete a typical single-hop two-way relay communication in this way, only two time slots will appear in the middle instead of three in the traditional transmission strategy, which is equivalent to increasing the theoretical throughput by about one-third..."


    ??The jump in this derivation is indeed a bit big, but it actually made Wu Wei''s eyes clearer.


    Looking at the other party''s look, Chang Haonan knew that he probably couldn''t explain the two paragraphs just now, so he had to return to the No. 1 car and take out his notebook -


    While waiting for the results of those rounds of experiments, he had already written down some ideas on it.


    "Under the constraints of half-duplex conditions, the system needs to perform two phases, uplink and downlink respectively, to complete a two-way relay communication. In the uplink phase, node 1 and node 2 simultaneously send their respective data frames S1 and S2 to node R, and in the downlink The stage is for node R to perform demodulation and network coding mapping based on the received superimposed electromagnetic wave signal, form a network coding data frame SR and broadcast it to node 1 and node 2. "


    As Chang Haonan spoke, he found a page with relevant content from his notebook and handed it to Wu Wei:


    "Because there is a mapping relationship between the superimposed waveform and information, the node only needs to use the encoded data frame SR and a data frame it originally owns to recover another data frame. At this time, the entire two-way communication process has been completed, and there is no need Here comes the third time slot.”


    “Of course, the focus of this process lies in the specific scheme of processing the received superimposed electromagnetic wave signal by the relay node R. I haven’t fully thought about how to design this..."


    ??Wu Wei listened to Chang Haonan''s explanation while his eyes quickly scanned the contents of the notebook.


    Although the illustrations are a bit abstract and the handwriting is more fluent, he is not a newbie with zero basic knowledge. Moreover, there are notes next to the teacher teaching on the spot, so he can quickly understand the above content.


    after…


    ?He couldn''t help it and read it again.


    ?Although the above does not involve the engineering implementation methods, even if it is just from the perspective of ideas, it is enough to impress people.


    ?It''s a pity that the two of them are standing on the Gobi Desert and there is no table.


    ?So Wu Wei had no choice but to do the next best thing and slapped his palm on the hood next to him:


    “Mr. Chang, isn’t this another implementation of network coding at the physical level?”


    ?This summary is indeed insightful, and can even be said to penetrate the phenomenon to the essence.


    Even Chang Haonan couldn''t help but look at him differently.


    “This is really the case from a principle level…”


    He nodded:


    “In my opinion, this technology is called physical layer network coding technology...”


    …”


    …


    ?At the same time, Chang Haonan was busy developing a two-way communication relay system.


    Another key project in the hands of the Aerospace Power Group has also achieved important phased results.


    ?After about a two-year research and development cycle, the first SeA650 prototype in complete technical condition was finally assembled and rolled off the assembly line at Snecma Group’s factory in Villaroche.


    Moreover, a few days ago, Snecma''s wholly-owned subsidiary Herrell-DuBois Group had also produced two sets of engines for the first prototype according to the design provided by China. nacelle.


    ?This also means that the power system of the entire Falcon Z project has officially entered the actual machine testing stage.


    Of course, since the entire SeA series of engines uses the core engine of M88-3, which has previously conducted a total of thousands of hours of single experiments in China and France, the whole process will not be as long as a brand-new engine.


    ?If all goes well, we will definitely be able to catch up with the first flight of the model early next year.


    With new aircraft equipped with new engines, risks will definitely still exist.


    Especially when both sides use a lot of new technologies.


    ?However, thanks to their good aviation technology and excellent basic industrial level, Europeans do not have much psychological burden on this kind of thing.


    At the moment, there are no other alternatives available on the market.


    Only the BR700 series jointly developed by Rolls-Royce and BMW is considered to be at the same level.


    ??However, Dassault business jets have never used Rolls-Royce products in the past, and the Falcon Z has integrated flight and thrust control. If you want to replace the engine control system, you will even have to modify a special version of the flight control.


    In short, no matter from the market or technical level, it is better to go directly to SeA650. Anyway, judging from the situation of M88, there shouldn’t be any major mistakes.


    As the main designer of SeA650, Aerodynamics Group naturally sent a team to France to participate in the delivery ceremony under the leadership of Liu Yongquan.


    ?When an important partner comes to visit, unless there are special needs such as confidentiality, the reception methods are the same whether at home or abroad.


    First have a round of eating and drinking, and then introduce a history of the company''s development (if the company history is too short, skip it, or change it to the boss''s family history), then arrange a visit to different areas of the factory or R&D center according to the specifications, and finally have another round of eating and drinking .


    The formal ceremony will not be held until the next day.


    Liu Yongquan and others are basically facing this set of procedures.


    ?It must be said that as a veteran aviation company, Snecma’s final assembly plant is indeed worth a visit.


    Although Huaxia has made rapid progress in recent years and has approached or even achieved international leading levels in many individual technologies, there is indeed still considerable progress in the overall organization and management of the factory, as well as basic skills such as mechanical processing and manufacturing. space.


    Not to mention anything else, Liu Yongquan found many details worthy of learning from Liming Factory just as he walked through the workshop working environment and worker safety protection.


    ?Of course, he is here to visit today, not to study.


    ?So the group of people walked around and quickly came to the engine that would not be officially delivered until tomorrow, but had actually been tested on the bench for several rounds.


    As a small engine with a medium bypass ratio, the SeA650 is not large in size.


    Even because of the elimination of the afterburner, it is shorter than the M88.


    So that if a group of about thirty people wanted to watch, they would be divided into two levels: inner and outer.


    ?However, as Liu Yongquan, of course he can have direct and close contact with him.


    ?He leaned down slightly, put his head in front of the tail nozzle, and looked at the internal turbine structure.


    From the light coming from behind, it is easy to see that the prototype is still using turbine blades produced and exported by Liming Factory.


    As for the turbine disk…


    Although the view is blocked, the result is obvious.


    ?Snecma has been trying to mass-produce SeA650 turbine parts at its parts manufacturing plant in Gennevilliers since March this year.


    However, Paris is a trial production workshop, which can be regarded as a pilot environment, and there are still many differences from the actual factory.


    It took more than two months and still did not produce a complete batch of qualified products.


    With no choice but to place a new order with China before final assembly, it was used for the production of a total of four prototypes.


    ? Even to this day, Snecma has not publicly admitted that it will use parts provided by Liming Factory in mass-produced products.


    But everyone already understands it tacitly——


    The yield rate produced in two months is 0, which shows that there is a big problem in the process technology and even the process route, which cannot be solved by simply adjusting parameters.


    Whether it is a complete upgrade of an existing process or the development of a new process from scratch, the cycle is basically calculated in years.


    ?Your Falcon Z will make its first flight early next year as planned, and the product will be delivered the year after next at the latest.


    How can you have so much time to slowly research new technologies?


    It can only be topped up with imported parts first, and we can make long-term plans in the future.


    ?Just like when China introduced the Arriel 1C engine from France.


    It''s just that the offense and defense have changed now.


    But then again.


    In this way, the next move is almost obvious.


    As an important partner, Aerospace Power Group cannot wait for Snecma to complete technical research before kicking itself out of the supplier list.


    Hence, you must sign a minimum supply quantity and minimum delivery time guarantee contract.


    In other words, no matter whether Snecma solves the process problem or not, it needs to order no less than a certain quantity of products every year for at least x years.


    Or simply, within the entire life cycle of the entire series of engines, no less than xx% of turbine parts must be supplied by China.


    In fact, Liu Yongquan led the team on this trip. In addition to participating in the delivery ceremony, another important task was to communicate with Snecma and reach such an agreement.


    (End of this chapter)