The Military-industrial Scientific Research System of the Academic Master Chapter 396

Chapter 396: Unify thoughts and concentrate strength

 When Chang Haonan said this, he paused deliberately.

 Obviously, not everyone can immediately accept this concept from a theoretical level.

But he had already thought of this.

“The report just made by Comrade Liu Yongquan talked about the design method of compressor bending and sweeping Ye Shan, and I happen to have a calculation example here.”

Chang Haonan released the next PPT, which showed a large aspect ratio blade with an extremely complex shape.

“You can join me and experience the design process of this 'ultrhigh load adsorption curved swept combined leading edge edge blade'.”

This name directly made many people laugh.

As we all know, the longer the name, the stronger the person.

However, at the end of the 1990s, the domestic trend had not been spoiled by Europe and the United States, and such names with a series of adjectives were not too common.

Some keen people will find that Chang Haonan also marked several adjectives in front of the leaves in different colors, which seems to be intended to emphasize this point.

 Sure enough, he went on to explain:

“Pay attention to the several factors that need to be considered at the same time during the design process of our blade, and will have an impact on each other.”

"High load means that the single-stage boost ratio is high, and the efficiency of the blade itself must be sufficient; adsorption type means that a multi-slit adsorption type blade type is used to control the separation of the blade boundary layer; combined bending and sweeping means that bending and sweeping are applied at the same time. Sweep design, the blade is an asymmetrical complex shape in a three-dimensional space; the final leading edge strip means that we have also considered the adverse impact of the end wall effect on the compressor blade efficiency, and hope to reduce this as much as possible Influence."

 The smile just now disappeared.

 When designing, the more restrictive factors there are, the more difficult it will obviously be.

 And this "ultrhigh load adsorption type curved and swept combined leading edge edge strip blade" is obviously the type with full buff.

 Generally, when encountering this kind of situation, these design elements are optimized separately, and finally combined and put on the bench for actual machine testing, and the parameters are fine-tuned little by little.

This kind of gameplay that needs to be considered at the paper design stage is definitely a gameplay that I didn't dare to think of before.

 But everyone's smiles did not disappear, they just moved to Chang Haonan's face:

“Although it is a little complicated, as a calculation example, it is certainly typical enough.”

“Then let's do it step by step, first of all, give the simplest curved Ye Shan shape...”

With the assistance of calculation examples, most researchers with engineering backgrounds finally gradually understood the new method proposed by Chang Haonan.

 At first it was one-dimensional, then developed to two-dimensional, and then to quasi-three-dimensional...

Now this is called full three-dimensional, which sounds logical.

But after all, everyone here is a professional. After understanding it, they can almost immediately realize that the impact of this new theory on the field of aero-engine design is definitely not as ordinary as its name.

It is no exaggeration to say that if all the cakes Chang Haonan just drew can be realized, then the workload of the aircraft engine compressor design process may be reduced by an order of magnitude!

Considering that most of the reductions in the process are actual machine testing, the time, money and risk reduction saved in this round can almost cross the "quantitative change" and enter the category of "qualitative change".

In the past, the reason why aero-engine design was a job that required a lot of experience and a lot of practical testing was largely because the losses caused by viscous effects accounted for a large proportion of the total losses, including the amount of power added to the blades and the amount of clogging. It has a direct impact on surge margin and so on.

However, the quasi-three-dimensional design method that considers the S1/S2 flow surface highly relies on statistical methods (that is, guessing first and then iterating) for the calculation of viscous effects. Even the most cutting-edge method currently developed by General Electric and Rolls-Royce The streamline curvature method still requires a huge amount of experimental data to perform numerical fitting on aspects such as expansion loss, shock wave loss, gap loss, end wall loss, lagging angle and blockage estimation, which often takes several years. Even more than ten years...

Note that this is only the compressor part of the three major parts of the aircraft engine, and does not take into account the two hot-end components of the combustion chamber and turbine, as well as the coordination of the three.

In general, with the current technological means, it is not unusual to spend 15-20 years designing a new engine from scratch without a core engine or old model as a basis.

 In fact, it took about 15 years for the Turbofan 10 on the original timeline to move from instability to maturity.

 If the specific situation of three-dimensional viscous flow can be given directly through numerical calculation, then even with a conservative estimate, the entire compressor design process can be completed in about 2-4 years.

Of course, the premise of all this is that the manufacturing level is up to standard and the things on the design drawings can be produced exactly as they are. It's just that China's aerospace industry is full of shortcomings, and they must be strengthened from the beginning, that is, the design stage.

The reason why the TORC Multiphysics software designed by Chang Haonan emphasized the priority of ensuring the progress of the thermal coupling module from the very beginning is to expand its business in the field of material processing, especially the thermal processing of metal materials.

 This happens to be an indispensable technology in the development process of high-performance aero-engine hot-end components.

  China's lagging behind in the field of materials is often not due to the inability to produce the raw materials themselves, but rather to the fact that the products manufactured using the same raw materials do not meet the requirements.

 Compared with the compressor as a cold-end component, the research focus of hot-end components, especially turbines, is basically focused on “how to withstand the highest possible temperature”.

Generally speaking, increasing the temperature in front of the turbine can directly increase the gas flow rate, and it will not directly affect fuel consumption. It is the simplest and crudest, but also the most intuitive and effective way to increase thrust - provided that the overall design level can meet the corresponding standards, otherwise there will be a lot of trouble alone. High turbine front temperature does not mean high performance. The typical negative teaching material in this regard is the later Japanese XF6-1. The turbine front temperature of 1600°C is already on par with the fourth-generation turbofan engine, but the actual level is about the same. It's almost like a smaller version of Taiwan's RD33…

The lowest temperature in front of the turbine of the third-generation (fourth-generation by foreign standards) turbofan engine cannot be lower than 1200°C. If you want to achieve the target set by Chang Haonan for the turbofan 10, then this number will probably be Increase to above 1400℃.

 Obviously, no material can rely on its own properties to work stably for a long time at such a high temperature, so this requires some other tricks to help.

 TORCHMultiphysics has the potential to solve this problem.

 But this is no longer the focus of today.

 Hence, regarding the research and development of hot-end components, Chang Haonan only briefly talked about it in the final outlook part.

 No matter how awesome he is, it is impossible for him to introduce all the key technologies related to the third-generation turbofan engine in half an afternoon.

 In fact, even this brand-new compressor design method only has time to throw out the concept and briefly explain it.

 But it's enough.

Looking at the eyes of the nearly two hundred people in the venue, Chang Haonan knew that his mobilization was quite successful.

That's right, although he has been talking about technology on the surface, he is not just talking about technology.

 It's more about confidence.

Although the design and production of the turbojet 14 has been finalized, and the orders have been so high that the 410 factory wants to allocate part to the 460 factory in Guizhou Province to relieve the pressure, at least before today, everyone has no idea whether they can produce a turbofan immediately. 10" I have no confidence in this matter.

 For aviation power powers such as the United States and the Soviet Union (Russia), this kind of thing is basically not a problem.

 Since the previous generation model has been completed, it is basically a matter of course to continue to develop the next generation.

 However, in China, due to the fact that aerospace power projects have not been independently established for a long time in the past, there is often no technical inheritance relationship between various types of aeroengines, and each new model is almost started from scratch.

 This is also the case between turbojet 14 and turbofan 10.

 The former, which was deeply improved by Chang Haonan, has certainly applied many new technologies, but after all, only a very small number of people know this detail.

 It is normal for most people to have concerns.

 However, when doing projects, especially projects that require concentrated efforts, the most taboo thing is that people are not aligned and they are hesitant to look forward and backward.

 So today's report by Chang Haonan is to give a clear answer - Turbofan 10 can definitely be produced!

 So, after finishing talking about the technical aspects, he changed the subject:

"From the calculation example just now, you comrades should also be able to see that even if new design theories and design tools are applied, the research and development of the third-generation turbofan engine is still a huge task, and it is difficult to rely solely on one Two units of strength to complete.”

“So, in this matter, I think it should be carried out through joint research and development by multiple institutions.”

After Chang Haonan finished speaking, a burst of whispers suddenly sounded in the venue.

 Although he said "I think", anyone with a discerning eye can see that it is definitely not the opinion of one or two people who can express his position so clearly on this occasion.

 At least it needs to be approved by the Commission of Science, Technology and Industry for National Defense, or even a higher-level license has been obtained.

 But the question is, how to unite?

 (End of this chapter)

Chapter end