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 the 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 routine greetings. Instead, he said:
"Mr. Chang, we just climbed to 16,000 meters. After that, it was really difficult to control the plane. It was barely able to fly levelly. As long as I made a slight movement, the nose of the plane would point completely out of control..."
Although generally speaking, no matter what the test pilot did in the sky, No decision will be questioned, but after all, he only completed half of the test tasks due to his own reasons, so he felt it was necessary to explain the situation a little bit.
Chang Haonan's mentality at this time is quite good. After all, the Turbofan 10 is not just a single project, but the key to breaking the situation.
The subsequent domestically produced and upgraded J-11B, as well as the new J-10 that has been changed beyond recognition, all need this model as power.
Now the flight test is 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.
It’s a pity that the J-8C has only been Little Tiantian for two years now. I’m afraid he will have to become Mrs. Niu in another two years...
So he put it down very simply. He waved his hand:
"It doesn't matter, test flight is an uncertain process to begin with, and the plan was made to break it."
"Besides, this test flight was not completed. The fundamental reason is that the performance of our engine is very good, and it is nothing to be ashamed of. If you have the opportunity to write a memoir or something in the future, just remember to describe this matter in detail.”
Chang Haonan's joke caused a burst of laughter around him.
Including Song Shangcai, he was obviously relaxed.
After all, it was not lunch time yet, so after a brief welcoming ceremony, everyone quickly got back to work.
Technicians from Factory 112 towed the aircraft back to the assembly workshop to conduct structural inspection after the first flight to confirm that the aircraft did not suffer any invisible damage.
The engineer in charge of 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——
The combination of digital fly-by-wire and flight-propulsion integrated technology is the standard configuration of the next three and a half generations of fighter jets. Therefore, while serving as a turbofan 10 demonstrator, this J-11WS is actually responsible for the verification task of the flight control system.
One flight to meet the requirements of three project teams.
It can be said that the price/performance ratio is excellent.
......
After a simple lunch, the test flight data obtained from the flight recorder was imported into the computer.
From a qualitative point of view, the performance of the turbofan 10 on the aircraft is almost completely consistent with the simulation test results of the high-altitude platform.
However, quantitatively, after the engine change, the performance of the J-11's inlet did exceed Chang Haonan's expectations, so much so that at high altitudes and subsonic speeds, the thrust performance of the turbofan 10 was even better than expected. better.
“No wonder the test pilot comrade responded that it is difficult to control the aircraft at an altitude of 16,000 meters.”
Liu Yongquan, who has been serving as Chang Haonan’s deputy, pointed with a pen at the thrust on the curtain. Curve:
“In fact, at an altitude of 14,000 meters, the thrust data of the AL31F began to decline significantly.”
"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 already considered a bold move for an expert..."
"Going to the back, after turning off the afterburner and ending the test state at the same time, the two The difference between the engine in the middle thrust state is even greater, so under the automatic operation of the flight control system, the turbofan 10 achieves a thrust balance with the right engine by reducing the speed by about 30%, and also agrees with the test pilot. The reported situation is close."
Following that, Liu Gaozhuo, deputy commander of Project 11, who was responsible for the design of the flight control system, changed to another slide:
"The flight control system recorded. The data also shows that when the pilot's action of adjusting the throttle opening is 0, the average time for the turbofan 10 to start responding is 0.53 seconds, while the AL31F is 0.97 seconds."
"And. , in terms of thrust adjustment speed, the former is also 55% faster than the latter on average. 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 only be determined after conducting mid- and low-altitude tests in no-man's land."
At this time, Chang Haonan continued:
"This is normal. , and it has little to do with the flight control system. In order to reduce the structural complexity of the turbofan 10, the adjustment ability of the ejection nozzle itself at low altitude and low speed will be weaker than that of the convergent expansion type. "< br>
“As for the remaining conclusions, let me briefly summarize them...”
“…”
After concisely summarizing the results of the first test flight, he paused for a moment and then talked about another topic:
“According to the current planned progress, we will be able to start using dual engines after the Spring Festival. The turbofan 10 is undergoing flight testing, and all the envelopes that cannot be made in a single-engine state have been completed. "If nothing happens, both models of turbofan 10 will be trial-produced in small batches by the second half of this year." In the form of providing products to two models of third-generation aircraft, I wonder where Mr. Liu’s upgrade progress is for the J-11?”
If others say it, an aero engine? It only took one year from bench testing to small batch trial production. No one would take it seriously.
But since these words came from Chang Haonan’s mouth, everyone couldn’t help but ignore them.
Therefore, Liu Gaozhuo, who was sitting across from him, replied with a serious face:
“Together with the engineers from Sukhoi, we increased the use of composite materials in the skin part to reduce the empty weight and also reduce the empty weight. Part of the weight is allocated to the structural components, and combined with a more detailed flight control system, it basically removes the overload restriction of the aircraft within a specific speed range."
"A set of heavy-duty mounts are added to the inside of the wing. points, increasing the total number of pylons to 12, but the carrying capacity of these two pylons is currently only 2000kg, which is still not as good as the two unlimited weight pylons located on the belly..."
" 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 head is reduced from 1000mm to 930mm, the heat dissipation power is increased by nearly 200%. There will be sufficient conditions to install higher-performance flat-panel slot antennas and even electronically scanned antenna radars in the future..."
< br>
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 plus 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 is it expected 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:
< br>"As far as the aircraft itself is concerned, the only obstacle currently is that the frame structure of the second half 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 also your main project, so efficiency should not be a problem."
When he said 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 is 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 fully upgraded turbofan 10 engines. The production of the new model J-11B/J-11BS with a new airframe, 1493 radar, centralized flight computer and digital fly-by-wire flight control depends on the supply of new engines."
"At the same time, production of 1 more will continue. - 2 batches, that is, 24-48 aircraft, will only be upgraded with new radars and semi-glass cockpits, and the rest will remain unchanged. They are currently tentatively named J-11AM and J-11ASM, allowing the Air Force to expand the third-generation fleet as soon as possible. , to ensure immediate combat capability in the next two to three years.”
“After a few years, when the production efficiency of the turbofan 10 increases to a sufficient level for supply, we can smoothly transition to full-scale production of new improvements. Type..."
After introducing the production plan, Yao Mengna raised her head again and looked at Chang Haonan, pushing up the round glasses on the bridge of her nose:
"How about this plan?"
Of course it is very good.
Chang Haonan thought in his heart.
Based on the current conditions, this is basically the most secure 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 the turbofan 10..."
This issue also gave him a little headache.
What restricts the production speed of turbofan 10 is the three major components of the hot end - turbine disk, turbine blades and combustion chamber wall.
Mainly to improve 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 reward points will not be enough for such a waste.
Therefore, Chang Haonan had no choice but to resort to a delaying strategy:
"In terms of production efficiency, I will think of a way in the future and strive to provide enough engines for the two models as soon as possible..."
(End of Chapter)