"Xiao Chang, because of the weather in Guizhou Province, the comrades of Guihang Industry said that they will not be able to come over until tomorrow, and our seminar can only be postponed for one day.

After a short greeting, Song Wencong, as the host, immediately gave the next itinerary.

The reason why we have to wait for Guihang Industry to come is because the flight test data about the DSI air intake tract was tested by three Jianjiao-9 prototypes, so they are all stored there.

After all, aircraft design still requires a certain amount of measured results, and it is impossible to rely on wind tunnel experiments alone.

Moreover, the more the school of computing like Chang Haonan is, the more so.

"It's okay, I've been dealing with the Taihang project for a while, and I really haven't paid much attention to the situation on the host's side."

This kind of big project, no matter how urgent it is, will not take a day or two, so Chang Haonan readily agreed.

In fact, when the plane landed just now, he saw through the porthole that on the other side of the tarmac, there were two fighter planes with obvious appearance and characteristics.

Sure enough, after simply going through some necessary procedures, the other two took Chang Hao south to get into a minibus and drove towards the distance.

Factory 132 is also considered to be the main factory in the aviation industry system, and it is naturally impossible to have only a few J-10 production tasks, so Chang Haonan also saw many other very familiar models along the way.

Among them even includes a J-7 with a large delta wing and nose air intake.

You must know that due to the emergence of the J-7F, even the J-7MG, which sold well in the previous life, almost ran out of orders.

"The oldest J-7 is still in production?"

Chang Haonan looked out the window and asked with a little surprise.

"It should have been discontinued, but the Sudanese Air Force lost four J-7N a while ago and needed to be replenished."

Xu De, deputy chief engineer of Factory 132, who was sitting in the back row of Chang Haonan, replied.

He is also the deputy chief engineer of the No. 10 project in charge of the final assembly and production tasks, and he has had a lot of business exchanges with Chang Haonan during the first ground test of the J-10, which can be regarded as acquaintance.

"We suggested that they directly buy the J-7F or at least the J-7MG, which is more suitable for the low-altitude ground attack mission over there, but the other party really can't afford it, and it just so happens that we have a few J-7II airframes, so we dismantle the friend or foe identification device and the alcohol anti-icing device, and prepare to deal with it directly as scrap iron."

In Africa in the 90s, there was still an environment where there was even a large-scale famine, and it was obviously not easy for a real third world country to save money to buy a few new planes.

"But speaking of which, what did the Sudanese Air Force do to lose 4 aircraft at once?"

In Chang Haonan's impression, the other party should be equipped with a total of more than ten or twenty J-7 and MiG-21, of which the number of those who can fly is definitely less, and they can drop four at a time......

It can't be a collision when flying in formation, right?

"We don't know much about the specific situation, we only know that it hasn't been peaceful over there recently......"

Song Wencong shook his head and replied in a slightly helpless tone:

"The separatist forces in the south are making a lot of noise, and a few days ago I heard that the Americans launched two air strikes on the grounds that they supported the KB elements, and I guess that's how those planes were lost......

After the end of World War II, the 90s were the most difficult period for many small countries.

The situation of the United States being the dominant power in the world cannot be changed in a short time, and the Internet age has not really arrived after all, so such small-scale air strikes will not even be reported in the news.

Even Chang Haonan, who was a reborn, didn't know that there was such a thing if he hadn't asked by this coincidence.

"This kind of thing...... The whip is beyond the reach of the ......"

Yang Wei, who was sitting in the same row of seats as Chang Haonan, also sighed.

At present, Huaxia itself has to make continuous concessions to the United States in many places, and after the disintegration, Da Mao still has the idea of trying to join NATO, so ......

It really can't be helped.

Some things are just unreasonable.

If you fall behind, you will be beaten.

That's why we must build a strong army, even if we focus on economic development.

"I just don't know where the Sultan offended Lao Mei this time......"

Obviously, these people sitting in the car are not true to the so-called "support for KB-ism".

However, this unintentional sentence made Chang Haonan suddenly remember.

At the end of last year, Yan Zhongzhong was designing a turbojet-14 conversion gas turbine for natural gas power generation for an oil and gas field project in Sudan.

And the reason why there was such a rush on the project was that General Electric suddenly stopped supplying the LM2500.

The ostensible reason is that Huaxia may obtain spare parts for its marine LM2500 gas turbines through this order.

In practice, however, it was due to the Sudan's suspension in 1994 of Chevron's oil exploration and exploitation rights in the southern part of the country.

And if you connect these things......

It seems that it is not difficult to explain.

Oil is known to breed mold.

Fortunately, at the moment, due to the incident of the fall of the Black Hawk, the Americans still have a lot of psychological shadows for this part of the Horn of Africa, so it should not be possible to send ground troops to the past.

And the leader of the other side, Omar al-Bashir, is, after all, a ruthless man who personally participated in the Yom Kippur War.

Judging from the fact that the Sultan immediately came to Rongfei to replenish the air force equipment, it seems that they have no intention of changing their development strategy because of this matter.

But even so, it's not a way to go in the long run—

Others are risking and stressing to give you this opportunity, but you can't protect the other person's basic safety.

In this case, before anyone chooses to cooperate with you, you must have to worry a little more.

……

In the midst of my thoughts, the minibus finally drove to the other side of the tarmac.

Everyone got out of the car one after another.

The two prototypes of the J-10 were parked here.

The surface of one of them is wrapped in a classic camouflage raincloth.

The other one is marked 1003, which should be the prototype of No. 03 that has just rolled off the assembly line.

"According to the data obtained during the test flight of the No. 01 aircraft, we made some technical adjustments to the No. 03 aircraft during the manufacturing process, after all, according to our planning, this model will also go through the entire finalization process in the future."

Chang Haonan walked to the plane and took a closer look, and sure enough, he found that the six stiffeners on the air intake had been adjusted and changed to the original production model.

In addition to reinforcing the air, it also has a slight rectifying effect on the air flowing through this area.

As for the other changes that are visible to the naked eye, there are only some details such as the landing gear door.

The main thing should still be on the flight control system.

"In addition, during the test flight, we found that under supersonic conditions, due to the pre-compression of the incoming flow by the nose, the part of the belly close to the body will form a bow-shaped shock wave, which will cause the pressure gradient to change at different positions, and the separation tendency of the surface layer will be strengthened."

Song Wencong stood on the edge of the air intake, stretched out his hand and gestured at the position of the upper partition:

"In this case, the mandibular air intake of the J-7F does not exist because it is positioned forward."

"At present, whether it is a binary adjustable air inlet or a pitot tube air intake, the air intake is designed at a distance from the belly, so this shock position can be avoided."

"But if it's a DSI intake, this bow shock is bound to have an impact on the air intake situation, further deteriorating supersonic performance......"

Obviously, after determining the improvement plan of the J-10, Rongfei has started part of the technical research and development work in advance.

And as a fighter, although it is acceptable that the supersonic performance is somewhat inferior, it cannot be too outrageous.

Especially in the case that the turbofan 10 also specially optimizes the supersonic orientation, if a defect occurs in the process of designing the aircraft body, it will be a bit of a loss.

"It's really not easy to solve this problem with the bulge design of the DSI inlet tract alone."

Chang Haonan patted the little dust that stuck to his hands just now because he touched the air intake:

"Therefore, it may be necessary to add several vortex generators along the lower edge of the intake tract to interfere with the generation of this bow shock wave in advance."

As he spoke, he raised his hand again and gestured above the air intake of the plane in front of him:

"The principle is a bit similar to these six stiffeners, the structure is very simple, but it takes some computing power to design."

"Wait for tomorrow the comrades over there in Guihang to bring over the test flight data of Jianjiao-9, and we will make specific considerations."

(End of chapter)