Chapter 87 The problem of aviation power
On the other side, Hao Jing and Yan Liang.
After completing the analysis of the engine surge failure, Chang Haonan finally made time to rest for a few hours.
There are still some comrades in the joint power research team who are inspecting and analyzing the damage to the No. 01 prototype to confirm the specific impact of the failure and eliminate other possible causes of the accident. It is estimated that it will take a while tomorrow morning.
Of course Chang Haonan does not need to complete this job.
But his mission is far from over.
Finding the problem is, after all, only the first step in a long journey of thousands of miles.
The key is to solve the problem.
Although the compressor of the turbojet engine and the air-conditioning fan he studied before can be classified as "turbine machinery", the difference between them is that of the Flyer One, which also belongs to the "aircraft" category. Similar to An 225.
After dinner, Chang Haonan was walking around Yan Liang's factory while thinking about the subsequent plan.
Since he has a work permit from the August 3rd Project on his chest, he can naturally move freely throughout the entire site. Only a few buildings or rooms require additional permissions, and normal walking is obviously impossible and there is no need to go to such places. .
So along the way, Chang Haonan's thoughts were completely focused on aeroengines.
The current impeller machinery design system has always used the traditional idea of "steady wall flow pattern".
Once the flow separation caused by the airflow expansion flow in the compressor occurs, it is no longer within the scope of the above flow pattern.
Since conditions other than wall flow have not been considered from the beginning, it is almost inevitable that flow disorder or loss of control will occur under non-design conditions.
From this perspective, the most direct and effective way is to increase the stall margin and delay the occurrence of flow separation by changing the blade design.
In particular, the turbojet 14 is an existing design. If modifications are to be made, the original design ideas must be retained.
After a period of research on swept blades, Chang Haonan is confident that he can solve this problem quickly. As long as the efficiency of the 410 factory responsible for engine manufacturing can keep up, there will be no impact on the progress of the Eighth-Three Project. have a particularly significant impact.
But for the Chinese Air Force, which is about to enter the third-generation aircraft era, the turbojet 14 can only be a transition after all.
It cannot hold up the future sky of a great country.
Chang Haonan's thoughts flew to further places involuntarily.
J-10 and J-11, both third-generation aircraft have the same target power.
Whipfan 10.
But I borrowed a joke that was popular on the Internet before he was reborn.
Is the 1996 Turbofan 10 coming?
——Tathagata.
It is really Tathagata.
At this time, nearly 10 years have passed since the establishment of the Turbofan 10 project, but when it comes to the progress of the project itself...
There is basically no progress.
Or Schrödinger’s progress.
The turbofan 10 project initiated in 1987 and the turbojet 14 developed almost simultaneously.
With no experience in engine design, even second-generation engines such as the turbojet 14 have obvious traces of patchwork and reference, let alone the case of the turbofan 10.
Although the design goals and design locations have not been changed as many times as the Turbofan 6, it is inevitable to overturn the overall design plan many times.
Even the original plan was changed midway.
At this time, the turbofan 10 should be in the process of a certain design plan being reset to zero.
In fact, this is also normal.
The steady wall flow pattern mentioned earlier has its limits after all. On this theoretical basis, it is almost impossible to design a compressor with high pressure ratio and high load.
Because flow separation itself has two sides. Chang Haonan once again thought of the field of aircraft design that he was more familiar with and experienced.
About twenty years ago, the design idea of the aerodynamic distribution of the aircraft shape crossed from the "steady attached flow pattern" to the "steady/detached vortex mixed flow pattern".
That is to say, from "suppressing flow separation" to "utilizing flow separation"——
Intentionally causing the aircraft's high angle of attack to break away from the body flow state, and using the concentrated vortex generated by flow separation to obtain additional vortex lift, thereby not only It greatly increases the lift of the wing and greatly expands the range of the wing's angle of attack, making a leap in aircraft performance.
What is reflected in the products is the stage when fighter jets evolve from second-generation aircraft to third-generation aircraft.
“Can this idea be introduced into the aerodynamic design of the compressor?”
This idea jumped into Chang Haonan’s mind almost without warning.
Of course, it's difficult.
Because it is necessary to fully understand the internal flow of the cascade, especially the rules of separation flow.
A common path taken by scientific research is from complexity to simplicity, and then from simplicity to complexity.
First abstract the specific natural phenomenon into a simpler model, conduct research and get a basic understanding, then gradually cancel the assumptions made, modify and expand on the basis of the basic understanding, until finally we get A comprehensive understanding of complex concrete phenomena.
Typical examples are from Newton's classical mechanics and Maxwell's classical electromagnetism, to relativity and quantum mechanics.
Now, in terms of boundary layer flow, we have just completed the "from complex to simple" stage.
Numerical simulation can probably only achieve two-dimensional steady calculations, which is even some distance away from quasi-three-dimensional calculations.
Chang Haonan's brain felt a little swollen when he thought of this vast amount of knowledge.
Before his rebirth, he was not a powerful person. He only knew a lot of things but didn't know why.
The above mentioned are only problems in the field of aircraft engine compressor design.
In addition, there are combustion chambers, turbines, fans, bearings, tail nozzles...
After the design is completed, it must be implemented into manufacturing.
……
The system’s capabilities are undoubtedly powerful, but there are also two limitations. One is the need for points, and the other is the need to first have a certain theoretical foundation and complete basic tasks. The project can only be formed after the framework of ideas is built.
Although at the beginning of his rebirth, Chang Haonan had realized that his own strength alone was completely insufficient.
But after all, he underestimated how quickly the pressure would come.
“Huh——”
Chang Haonan let out a long breath.
“There still has to be a team, and it must be a team with me as the main leader.”
In addition to the “output” process of promoting the new models and new theories that I have developed, , he also needs an "input" process.
That is to let others be responsible for constructing the basic thinking framework, or at least provide him with sufficient theoretical knowledge.
Opening the system panel and looking at the person with only level 1 engineering experience, Chang Haonan shook his head mockingly.
Before rebirth, I had only led small projects with no more than 4 people including myself.
After being reborn so far, I have only taken along a few people like Lin Shikuan.
There is progress, but not enough.
Thinking of this, he stopped and prepared to walk back.
The current work of improving the turbojet 14 seems to be a good opportunity.
(End of this chapter)