Chapter 62 I want to go to heaven
With one sentence, everyone's attention once again focused on Chang Haonan behind the conference room.
Only this time, he could hardly feel the suspicion in everyone's eyes.
After clearing his throat, Chang Haonan revealed his specific plan:
“The risks we face now mainly come from the uncertainty of the gap between the results of computer simulations and the actual situation. How big it is, so it can be verified in two steps.”
“The calculation of aileron efficiency is essentially a flow field analysis, so we first select a working condition that ensures safe test flight, such as 1.2 times the speed of sound and an elevation angle of 10°, and then I calculate the flow rate of the wing surface in this case. flow field distribution, and then conduct a test flight.”
“If the results obtained from this test flight are consistent with the calculation results, it means that there is no problem with the accuracy of the calculation results. The next step can be more radical, directly in. Conduct a test flight near the operating point where aileron reversal occurs"
This idea was actually inspired by the previous 603 Institute. When the latter verified the active flutter control technology, it was divided into two in a similar way. steps, while accelerating the verification progress and controlling the risk within an acceptable range.
Of course, it is acceptable, but after all, it is not as reliable as the most conservative successive approximation method, and Yang Fenghata, as the chief designer, still needs to bear a certain amount of pressure.
As soon as Chang Haonan finished speaking, a young-looking engineer not far away asked:
"This method is indeed feasible in theory, but your first step is to verify the flow field on the upper surface of the wing when you are carrying bombs. How should you proceed?"
Because of the sensors in the 1990s The technology is not advanced enough, so it is difficult to measure the flow field distribution on the entire wing surface in real time. In many cases, judgment needs to be made based on the subjective feelings of the test pilot.
The wind tunnel model is okay, but the degree of restoration cannot be compared with the test flight.
It’s just that Chang Haonan doesn’t even need to answer this question.
“Engineer Zhao has just joined the work two years ago, so he may not know much about some things. Our 601 Institute has already had experience in solving such problems.”
This time it was the old engineer Xu Jin who opened his mouth to explain to Chang Haonan.
In fact, he has no prejudice against digital design itself. After all, people who engage in aircraft design cannot really be antiques. He just thinks that Lin Shikuan and the others just waste money and do nothing.
So after he just saw the report brought by Chang Haonan, he was very curious about how far the other party could achieve it.
“When we were working on the J-8B before, Commissioner Gu relied on sticking wool on the fuselage to observe the airflow on the surface of the fuselage. This solved the buffeting problem that had troubled us for a long time. Now it can be used again. The same method every time. "
The title academician only began to appear in October 1993. Before that, it was always called academic member, so it is normal for older people to not change it for a while.
Chang Haonan looked at Xu Jin who was not far away and looked expectant, and continued to add with a smile:
"Engineer Xu is right, you can choose a few representative spots on the surface of the wing to affix them. Get the yarn on and find a two-seater plane to fly with you, so that you can intuitively observe the airflow at the corresponding position. After the test flight, you can compare it with my calculation results to draw a conclusion. "< br>
Of course Xu Jin is not the only one who agrees with this idea.
"Divided into two steps... This idea is somewhat similar to the advanced results reported by Haojing some time ago..."
I saw that someone in the conference room had already mentioned 603 Regarding the matter, Yang Fenghata also took advantage of the situation and said:
"In fact, everyone here may not know that the main person who completed the result just reported by the 603 Institute is Dr. Chang Haonan."
One stone stirred up a thousand waves.
Although many people have heard about the MA-60 project, they still don’t understand some details because it has not yet reached the end of the year for internal publicity. Except for a few leaders such as Yang Fenghata, no one here at the 601 Institute had previously known that the first person to complete the results of the 603 Institute was actually from Beijing Hang University.
“It was him...”
"It's really impressive to be the first completer at such a young age..."
"..."
These front-line engineers are also engaged in confidential work. If you say who published what paper, you might not care too much.
But the advanced results evaluated by the Aviation Industry Corporation of China or the Commission of Science, Technology and Industry for National Defense are definitely something that everyone is keen on.
Being able to put a name on it is something worth writing about for many people, and Chang Haonan, who looks like he is no more than twenty-five years old, is actually the first to complete it. People.
After the discussion calmed down a little, Yang Fenghao tapped the table lightly with the pen in his hand:
"Considering the experience of the Brother Research Institute, I think this method proposed by Comrade Chang Haonan It should be feasible, so let’s do it. As for the candidates to fly to the sky with the plane..."
"Since I am responsible for the calculations, let me do the work of flying to the sky."
< br>When he first proposed this plan, Chang Haonan had already thought about doing it himself:
In addition to the sense of responsibility, there is also a less important reason that he really wants to experience it. The feeling of flying in a fighter jet.
"The conditions now are much better than those of Mr. Gu's time. I can bring a camera up and take pictures of the airflow pattern on the wing of the prototype."
Gu Yongfen was designing the J-8B back then. At that time, I brought a telescope for on-site observation. However, in 1996, cameras with optical zoom capabilities were already quite popular, and it was possible to take pictures and keep them for files, and then analyze them slowly after returning to the ground.
Yang Fenghao briefly communicated with the two deputy chief designers next to him for a while, then raised his head and said:
“We agree in principle on this matter, but we have to let it go. The comrades from the Air Force test flight unit will give you a physical examination and make sure you are fine before you can get on the plane."
Chang Haonan naturally had no objection to this. During the Air Force's physical examination for recruiting pilots, he only had misaligned teeth. It's just a disqualification.
...
What was originally an ordinary and routine progress seminar became extremely enriched by the appearance of Chang Haonan and lasted for six hours.
When all the details of the verification work were finalized, it was already close to midnight that day.
"The situation regarding the wing efficiency test has been decided first. After the meeting, Dr. Chang and Dr. Yao, as well as the digital design team, will come up with the simulation results of the flow field as soon as possible. As for the aircraft problem, I will contact my comrades in the Air Force and ask them to borrow a JJ-7."
Yang Fenghata concluded in a hoarse voice:
"As for comrades from other groups, let's continue with the work at hand. If the aileron reversal problem is verified by then, we will discuss the solution."
"Adjourn the meeting!"
( End of chapter)