After confirming that there was no problem with the accuracy of Chang Haonan's simulation method, all that remained was to conduct several more test flights to obtain detailed data on the aircraft at the time of the aileron reaction.

Thanks to the efforts of the test flight team, the two prototypes 03 and 04 took off in turn, and it took only five days to complete all the test flight work.

In the end, it was proved that Chang Haonan's calculation was completely correct, and when the airspeed and elevation angle of the aircraft with bombs reached a certain value, the phenomenon of aileron reversal would occur.

In fact, even if the payload is adjusted to two Aspidegar and two Thunderbolt 8s that are closer to actual combat, this situation is still unavoidable, but it will appear later.

With the end of the test flight work, Chang Haonan's system status has also changed.

[Research points: 85.]

Theoretical level: LV2 (0/)

Engineering Experience: LV1 (70/1000)

Management capability: LV0 (65/100)

Comprehensive ability: LV1

Projects in progress: 0

Possible Projects:1】

This is an increase of 10 research points and a whopping 50 management experience.

It's a good bona fid.

……

In the afternoon of the day when the complete test flight data was obtained.

It's still the same room, it's the same people from last time.

It's just that due to Chang Haonan's abnormal performance, today he and Yao Mengna and Lin Shikuan were directly invited to the position in front of the conference table close to Yang Fengyuan.

This time, the atmosphere in the venue has become much more solemn -

At less than twice the speed of sound, the aileron reaction occurs, and the corresponding deflection angle is only 10°.

It is equivalent to the corresponding roll rate of less than 30° per second, and it takes 3 seconds to do an ordinary 90° roll off action.

This is completely unacceptable for an interceptor that focuses on high-altitude and high-speed capabilities.

Therefore, everyone ruled out the answer to limiting flight performance by flight control from the very beginning.

The wing had to be modified.

In 1996, people weren't so shy away from smoking in public, so not long after everyone entered the room, the whole room was smoky.

Chang Haonan hated the smell of smoke very much, so he moved slightly closer to the window.

The first to speak, of course, was Yang Fenghat:

"Don't be discouraged, since the problem exists, it is better to find it as soon as possible, the sooner we delay, the less progress we will delay, so from this point of view, this is a great gift to us after Comrade Xiaochang and Comrade Xiaoyao joined the 83 project team."

After a moment of silence, it is not known who was the first to take the lead in applauding.

This was followed by thunderous applause.

This sentence not only praised Chang Haonan and Yao Mengna, but also boosted the morale of the entire project team.

After the applause gradually subsided, Yang Bonghata continued:

"In order not to delay the progress of the test flight of the 83 Project as much as possible, I decided to transfer the No. 03 prototype to Yanliang at the beginning of next month according to the previous plan, and first carry out a test flight that does not involve the bomb project, while the No. 04 verification aircraft will stay in the No. 112 factory and prepare for modification."

"Considering that in this way, the No. 03 aircraft can no longer be regarded as a full-state verification aircraft, so after the wing problem is solved, a No. 05 verification aircraft will be built from backup parts, and the No. 04 will be used to carry out a full-state verification flight together."

"This way, we have relatively plenty of time to improve the wing."

A few minutes later, Liu Ming, the deputy chief designer who was sitting on the left hand side of Yang Bonghata, finally spoke.

"Comrades, according to the data obtained from the test flights in the past few days, the reason for the aileron reaction is not complicated, and it is still the cliché problem of the accumulation of the attached surface layer."

"The simplest solution is to add a pair of wing knives on the wing where the lateral flow is most intense."

Chang Haonan nodded slightly.

The engineers of the 601 Institute still chose the same solution as later generations.

In fact, from the perspective of the present, it is indeed the best way.

During the flight, the airflow from the upper surface of the wing will automatically flow to the wingtip, and accordingly, the surface layer will gradually accumulate towards the wingtip.

The build-up of airflow will eventually separate at the wing tip, and this separation process will bring a large shear force, resulting in significant elastic deformation of the wing, which can lead to reduced or even negative effects on the ailerons.

The easiest way to avoid this is to add a pair of baffles to the upper surface of the wing to block the laterally moving airflow.

That is, the wing knife.

Still, there were those who disagreed

"But Mr. Liu, there are already two pairs of wing knives on the wing of the J-8-3 now, if you add another pair, is it a bit ......?"

Although the wing knife is simple and effective, it is not without cost, and its working principle is essentially to rupture the leading edge vortex early, so it reduces the lift coefficient and stall angle of attack, and there is still a certain impact on flight performance.

And there are too many designs, and the appearance of the wing knife is relatively bad.

"Is it possible to consider fusing three groups of small wing knives into one large wing knife, just like the J-6?" Another asked.

However, it was quickly denied:

"That can only reduce the weight a little bit, but the impact on lift and stall ability is greater, and the gains outweigh the losses for an aircraft as large as the J-8-3."

The heated discussion lasted about half an hour, and still no one agreed on a plan.

Finally, someone turned his attention to Chang Haonan, who had been looking down at the report in his hand and did not speak.

"Dr. Chang, since you discovered this problem, I wonder if there is a better solution?"

The room fell silent.

Chang Haonan stood up and walked to the blackboard with the test flight results and design drawings.

"First of all, I want to tell you the good news." Chang Haonan turned around, looked at the group of engineers in front of him and said:

"After the efforts of the entire digital design team in the past few days, the parametric modeling of the aerodynamic and structural design of the J-8-3 prototype has been basically completed, so the time taken to modify the design should be lower than expected."

Another extraordinary result.

The optimal design of the aerodynamic shape of the aircraft needs to evaluate a variety of different aerodynamic shapes, so it is necessary to repeatedly modify the aerodynamic shape of the aircraft in order to improve its aerodynamic performance.

Once a parametric model is in place, the geometry can be driven by changing the design parameters, which greatly shortens the geometry modeling cycle.

Lin Xi's people have been engaged in a task that has not made much substantial progress for a year and a half, and it was solved in less than ten days after Chang Haonan came.

Although the latter did not mention his own name, almost everyone assumed that this was a sign of his hidden merit and fame.

Then there was another round of applause.

Chang Haonan stretched out his hand and pressed down to signal that he would be low-key first:

"As for the wing improvement plan, I do have a less mature idea." Chang Haonan picked up an unsharpened pencil, gestured on the design and continued:

"The idea of adding a pair of wing knives was fine, but based on my simulations, the area with the most dense lateral airflow on the wing surface was near the trailing edge of the wing."

"Therefore, I think that the existing upper and lower aileron hinge fairings can be extended into trailing edge wing knives, so that the increased dead weight is almost negligible, and the appearance is closer to the original two-wing blades."

"At the same time, leading edge devices can be introduced into the wing design, such as leading edge flaps or leading edge slats, which can not only compensate for the impact of the wing knife on the lift coefficient and stall angle of attack in the medium and low speed range, but can even greatly improve the low altitude and low speed performance of the aircraft!"