The Military-industrial Scientific Research System of the Academic Master Chapter 647

Chapter 647 Flanker Evolution

First flight test, everything went well.

The triumphant Song Shangcai was naturally welcomed as a hero.

After all, no matter how much effort designers put in on paper, it is the test pilots who ultimately bear the huge risks on the front line.

The heads of the WS-10 and J-11WS projects took turns to hug him.

However, when it was Chang Haonan's turn, Song Shangcai, who was still holding a bouquet of flowers in his arms, did not leave immediately after the usual greetings, but said:

“Mr. Chang, after climbing to 16,000 meters just now, it was really difficult to control the aircraft. It was barely able to fly levelly. As long as I made a slight movement, the nose of the aircraft was completely out of control..."

Although generally speaking, no matter what decision a test pilot makes in the sky, he will not be questioned, but after all, he only completed half of the test mission due to his own reasons, so he felt that it was necessary to explain the situation a little bit.

Chang Haonan's mentality at this time is quite good. After all, Turbofan 10 is not just a single project, but the key to breaking the situation.

ˆ The subsequent domestically produced and upgraded J-11B, as well as the new J-10 that has been completely changed and reborn, all need this model as power.

“No wonder the test pilots responded that it was difficult to control the aircraft at an altitude of 16,000 meters.”

“It doesn't matter, test flight is inherently an uncertain process, and the plan was made to break it.”

From a qualitative point of view, the performance of the turbofan 10 on the aircraft is almost exactly the same as the simulation test results of the high-altitude platform.

It's a pity that the J-8C has only been a Xiaotiantian for two years now. I'm afraid it will become Mrs. Niu in another two years...

"At 16,000 meters, 1.4 times the speed of sound, the thrust has dropped from 12.5 tons to about 10.7 tons, while the thrust of the turbofan 10 has only dropped from 14 tons to 13.5 tons, a difference of 25%, and the automatic The trimming system is turned off, and it is purely controlled by hand. Being able to fly stably and level is considered a bold move for an expert..."

One flight to meet the requirements of three project teams.

The combination of digital fly-by-wire and flight-propulsion integrated technology will be the standard configuration of future three-and-half-generation fighter jets. Therefore, this J-11WS, while serving as a turbofan 10 demonstrator, is actually responsible for the verification task of the flight control system.

After a simple lunch, the test flight data obtained from the flight recorder was imported into the computer.

So he waved his hand very simply:

Chang Haonan's joke caused a burst of laughter around him.

The technicians of Factory 112 towed the aircraft back to the final assembly workshop to conduct structural inspection after the first flight to confirm that the aircraft did not suffer any invisible damage.

Including Song Shangcai, they were also obviously relaxed.

The flight test is now going well. Although there are still many subjects that need to be completed in the follow-up, we can already look forward to a new round of upgrades of the Chinese Air Force's main battle equipment.

The engineer responsible for writing flight control programs at Institute 601, together with Chang Haonan and others, are waiting to obtain test flight data and analyze and improve possible problems -

“Furthermore, the fundamental reason why this test flight was not completed is that the performance of our engine is too good, and it is not a shameful thing. If you have the opportunity to write a memoir or something in the future, remember to focus on describing this matter.”

“In fact, at an altitude of 14,000 meters, the thrust data of the AL31F began to decline significantly.”

Liu Yongquan, who has been working as Chang Haonan's deputy, pointed at the thrust curve on the curtain with a pen:

However, quantitatively speaking, after the engine change, the performance of the J-11's inlet did exceed Chang Haonan's expectations, so that at high altitudes and subsonic speeds, the thrust performance of the turbofan 10 was even better than expected.

It can be said that the price/performance ratio is excellent.

After all, it was not lunch time yet, so after a brief welcoming ceremony, everyone quickly got back to work.

"Further back, after turning off the afterburner and ending the test state at the same time, the gap between the two engines in the intermediate thrust state is even greater. Therefore, under the automatic operation of the flight control system, the turbofan 10 passes by about 30%. The rotation speed achieves a thrust balance with the right engine, which is also close to the situation reported by the test pilot comrade. "

Following this, Liu Gaozhuo, deputy commander-in-chief of Project 11, who was responsible for the design of the flight control system, changed to another slide:

“The data recorded by the flight control system also shows that when the pilot's action of adjusting the throttle opening is 0, the average time for turbofan 10 to start responding is 0.53 seconds, while the AL31F is 0.97 seconds.”

“Furthermore, in terms of thrust adjustment speed, the former is 55% faster on average than the latter. In other words, it only takes half the time of the latter to complete the entire thrust change process.”

"However, it is worth noting that the advantage of the turbofan 10 over the AL31F in terms of thrust response is that the greater the speed and altitude, the more obvious it is, and it is more obvious when pushing the throttle than when closing the throttle. If it is in the low-to-medium speed section below 6,000 meters, even It may be overtaken by the latter. Of course, this will not be determined until we conduct mid- and low-altitude tests in no-man's land.”

At this time, Chang Haonan took up the topic:

"This is normal and has little to do with the flight control system. In order to reduce the structural complexity of the turbofan 10, the ejection nozzle itself has a weaker adjustment ability at low altitude and low speed than the convergent expansion type. It's hard to give up. Well."

“As for the remaining conclusions, let me briefly summarize them...”

After briefly summarizing the results of the first test flight, he paused for a moment and then talked about another topic:

"According to the progress of the current plan, after the Spring Festival, you can start using a double -hair turbofan 10 flight test, and complete the bags that cannot be done in a single shot." Within half a year, two models of turbofan 10 have been supplied to two models of third-generation aircraft in small batch trial production. I wonder where the J-11's upgrade progress is at Mr. Liu's side?”

If you were to tell others that it only takes one year for an aero engine to go from bench testing to small batch trial production, no one would take it seriously.

But since these words came from Chang Haonan's mouth, there is no reason why everyone should not pay attention to them.

So Liu Gaozhuo, who was sitting opposite, replied with a serious face:

"Together with the engineers from Sukhoi, we increased the use of composite materials in the skin part. While reducing the empty weight, we also allocated part of the weight to the structural parts. Combined with a more detailed flight control system, it was basically relieved. The overload usage limit of the aircraft in a specific speed range.”

"A set of heavy-duty hardpoints have been added to the inner side of the wing, increasing the total number of pylons to 12. However, the load-bearing capacity of these two hardpoints is currently only 2,000kg, which is still not as good as the two unlimited weights located on the belly of the fuselage. Hang on..."

“In addition, by dynamically adjusting the sequence and distribution of fuel during flight, effective control of the aircraft's center of gravity is achieved to a certain extent, and the flow of the fuel cooling system in the nose part is also increased.”

“Although the effective diameter of the aircraft nose is reduced from 1000mm to 930mm, the heat dissipation power is increased by nearly 200%. In the future, there will be sufficient conditions to install higher-performance flat-panel slot antennas and even electronically scanned antenna radars..."

Chang Haonan listened to the other party's introduction and was quite satisfied with it.

The improvement direction mentioned by Liu Gaozhuo is basically a combination of the previous J-11B and the Su-30MKK. It can be regarded as the optimal solution that combines the advantages of China and Damao under the current technical conditions.

“Then...when can we expect to start producing this deeply improved model?”

The person who answered this time was Yao Mengna, who has been stationed at Factory 112 for nearly two years:

“As far as the aircraft itself is concerned, the only obstacle currently is that the frame structure of the rear part of the new fuselage has been changed from a tailor-welded process to an integrated forging process, so it cannot be manufactured until the 70,000-ton die forging press is put into production.”

“Of course, that project is yours, so efficiency shouldn't be a problem.”

When speaking of this, almost all eyes in the conference room focused on Chang Haonan for a moment—

One person is responsible for two national key models at the same time...

In short, it's outrageous.

Yao Mengna also took the opportunity to stare at Chang Haonan for a while, but she quickly continued her previous answer:

"However, according to Liming's production plan, their small batch trial production rate is about 16-24 engines per year. Considering that the J-10 after the revised plan must use a turbofan 10 to propel it, the quota that can be left for us is definitely It's not enough.”

“So, taking into account the increasingly tense pace of military struggle, our idea is to wait until the die forging press is put into production and then start small batch production of a fully upgraded turbofan 10 engine, a new airframe, 1493 radar, and a centralized flight computer. And the new model J-11B/J-11BS with digital fly-by-wire flight control, the output depends on the supply of new engines.”

"At the same time, we will continue to produce 1-2 batches, that is, 24-48 limited-edition models that will only be upgraded with new radars and semi-glass cockpits, and the rest will remain unchanged. They are currently tentatively called J-11AM and J-11ASM. Allow the Air Force to expand its third-generation aircraft fleet as soon as possible to ensure immediate combat capability in the next two to three years.”

“After a few years of waiting until the production efficiency of turbofan 10 has increased to a sufficient level for supply, we can smoothly transition to full-scale production of the new and improved model…”

After introducing the production plan, Yao Mengna raised her head again and looked at Chang Haonan, pushing up the round-framed glasses on the bridge of her nose:

“How about this plan?”

It is naturally very good.

Chang Haonan thought in his heart.

Given the current conditions, this is basically the most stable production plan.

“The die forging press… my plan is to use it as a National Day gift project. So far everything is going well, so… it will probably be put into production in the second half of this year.”

This sentence can be regarded as a reassurance for Factory 112.

After all, the limited improvement model is just a stopgap measure. The one that can really compete with the J-10 for the position of the main model of the Air Force has to be the serious J-11B.

“As for the production efficiency of turbofan 10…”

This problem also gave him a headache.

The production speed of the turbofan 10 is restricted by the three major components at the hot end—turbine disk, turbine blades and combustion chamber wall.

Mainly in order to improve the active cooling efficiency, special-shaped air film holes with very complex internal shapes are used.

The theoretical upper limit of EDM speed is basically what it is now, and the yield rate is frighteningly low. Simply buying new equipment to expand production will not be very effective.

After all, China is not so wealthy that it does not care about production losses.

As for using the system to forcefully open a technology tree for electrochemical processing...

Even if the two projects of turbofan 10 and die forging press are completed, I am afraid that the points awarded will not be enough for such a squandering.

Therefore, Chang Haonan had no choice but to adopt a delaying strategy:

“In terms of production efficiency, I will think of a way in the future and try to provide enough engines for the two models as soon as possible...”

(End of this chapter)

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