The Military-industrial Scientific Research System of the Academic Master Chapter 645

Chapter 645: Too good performance can sometimes be a source of distress

According to the requirements before the test flight, in order to prevent the distinctive chrysanthemums of this aircraft from being photographed by interested people as much as possible, the afterburner state should be maintained after takeoff until it climbs to an altitude of more than 3,000 meters before leveling off and starting normal test flight subjects.

The first reason for turning on afterburner is to climb faster, and secondly because if someone does squat during the climb, the dazzling tail flames will easily overexpose the camera, making it difficult to clearly capture images near the engine.

The thrust-to-weight ratio of the Su-27 when empty and light on fuel exceeds 1. The aircraft that was temporarily pulled out is the latest batch after weight reduction. Therefore, even a two-seat model with slightly less maneuverability can make such an action. It's still flowing smoothly.

In addition, the day was a little cloudy, so in just a few breaths, Chang Haonan and others holding the telescope could no longer see the shadow of the plane.

“Tsk tsk tsk…”

Although they could no longer see anything, except for Chang Haonan, who had been looking at Station 624 for almost a thousand hours, the others still looked unfinished, and even refused to put down their telescopes.

"This tail flame... is so blue that it turns purple..."

Luo Shida, who was standing on the left hand side of Chang Haonan, was a little hunched due to his old age and recent intense work, but at this moment, he stood up straight:

“I've never seen such a beautiful one before…”

The latter is now basically immune to this type of appreciation. Under normal circumstances, even when the other party is still preparing the groundwork, he has already prepared the polite words of routine response just by subconscious mind.

The result was that I was completely speechless for a while.

“Yes, the temperature was still relatively low when we first designed it, but the cooling technology and new coatings developed later were so effective that it was raised by more than 200 degrees..."

Chang Haonan was halfway through speaking before he felt something was wrong——

But I don't think it's appropriate.

“There is no strategy to speak of. The main thing is that the project team members work together. Otherwise, even if I have a ready-made plan, I won't be able to advance so fast..."

In fact, in the years before Chang Haonan was reborn, as the temperature in front of the aircraft turbine increased to more than 2000K, engineers no longer believed that there was a strict correlation between the color of the tail flame and the temperature.

So after thinking for a moment, he replied:

“Where, not just...”

When Luo Shida on the opposite side saw him being speechless, he confirmed the plot he had just imagined. He stopped talking and just turned back with a mysterious smile and raised the telescope again. , looked at the sky where there were only clouds left, and at the same time took the initiative to change the topic:

“The tail flame of this color…the temperature in front of the turbine must be quite low…”

As a result, when Luo Shida heard his answer, he was not in a hurry. Instead, he smiled mysteriously:

“It doesn't matter, I understand, the string of confidentiality needs to be tightened... You don't need to answer directly...”

Why does this old comrade's focus seem different from others?

But the other party is an elder after all, and Luo Shida is also a Taishan Beidou-level figure in the field of aviation manufacturing, so he cannot let the other party stand aside.

“I, Mr. Luo, have only retired a few years ago, but I had never heard of such a turbofan 10 before the year before last. Comrade Haonan really has a good idea...”

Chang Haonan was completely confused. He almost blurted out and asked the other party what he knew.

But Luo Shida did not play his cards according to common sense at all:

At this point, he finally put down the telescope and turned to look at Chang Haonan next to him:

"The waves behind the Yangtze River push the waves ahead..."

So he nodded directly:

However, as we approach the millennium, this understanding cannot be said to be problematic.

If the latter continues to think like this, there won't necessarily be any outrageous plot.

Chang Haonan's answer made Luo Shida raise his eyebrows. Hearing this, he thought to himself, the Turbofan 10 also encountered an iterative upgrade of active cooling technology during the development process. It will definitely not be completed in less than ten years. My previous guess Sure enough...

Fortunately at this time, Song Shangcai's voice came over the radio:

“Report to the command center that it has reached an altitude of 6000 and requests to switch the flight mode to the 'test' state.”

The people standing in front of the window suddenly became serious again, put down their telescopes, and returned to the radar screen in the command center.

“Received, approved the request.”

The commander sitting behind the communication terminal replied decisively.

At the same time, in the cockpit of Unit 1010, Song Shangcai quickly entered a series of four-digit numbers on the multi-function display, and then pressed "Confirm" to release the flight mode lock restriction—

As He Ming said before, the flight control of this J-11WS has been verified on the J-8IIACT a long time ago. In addition, the turbofan 10 has full digital control capabilities, so it directly integrates flight and thrust at the control level. change.

It can even be regarded as the second Flanker in the world with this ability.

At the flight control level, it is directly on the same starting line as the No. 711 high-mobility demonstration aircraft.

Compared with traditional flight control systems that control the rudder and power separately, the biggest advantage of integrating flight and thrust is that the movements of the pilot's hands and feet no longer directly control the power and rudder of the aircraft, but directly control the aircraft's Behavior.

For example, the most common action is to push the throttle lever with the left hand.

In the past aircraft, this action actually increased the engine speed, thus pushing the aircraft to increase speed.

However, as to how, how much, and when the rotational speed is increased, it is up to the pilot to make his or her own judgment.

For a control system that integrates flight and thrust, pushing the throttle lever is only equivalent to giving an acceleration command to the aircraft. The flight control will automatically coordinate the cooperation between the engine thrust and the rudder surface to make the action expected by the pilot. .

This ability is basically useless for normal aircraft in level flight, but for fighter jets that need to perform various extreme maneuvers, it can greatly reduce the pilot's operating pressure.

On this J-11WS, considering that the aircraft still needs to ensure basic safety during takeoff and landing, and the flight test subjects are also completed in the sky, when designing the flight control, the thrust under normal flight conditions was specially considered. Control is handed over to the flight controller.

In other words, the test engine will automatically keep the thrust as much as possible with the other engine, and at the same time, the six control surfaces of the aircraft will also automatically adjust to try not to let the aircraft go astray.

This is also the reason why Song Shangcai saw that the pointer of the left engine tachometer was relatively small just before taking off—

When the full throttle thrust is greater, to ensure the same thrust as another engine, the speed ratio naturally has to be lowered.

It's just that the fully electronically controlled turbofan 10 adjusts thrust much faster than the electronically controlled + hydraulic AL31F, so at the moment when the throttle changes, you still have to move the lever slightly to ensure balance.

Now, after changing the flight mode to the 'experimental' state, these two layers of protection no longer exist.

The two engines will maintain the same throttle opening according to the position of the throttle valve.

Sure enough, almost the moment Song Shangcai pressed the confirmation button, the seal was finally released after he had been holding the turbofan 10 hard.

He felt the entire plane lurch sharply to the right, and almost subconsciously stepped on the left rudder, trying to pull the plane back to flying straight forward.

But anyone who has flown an airplane knows that without the involvement of flight control, the impact of power asymmetry cannot be compensated for simply by adjusting the vertical tail action surface.

So, even though Song Shangcai had made a lot of preparations before taking off, it was still a little difficult to control the amount of movement on his feet once he actually got started.

Especially when he was changing the throttle while performing preset flight movements, it was so awkward.

It took him three attempts to make a steep turn without losing height.

“Unit 1010, is there a problem?”

The tower commander saw the abnormal track on the radar and asked with some concern.

“Report to the command center that the thrust of the left engine is too great and the throttle response is much more sensitive than before. I need to get used to it for a while.”

Although Song Shangcai is not as experienced as Fu Guoxiang, he is also from a serious test pilot training unit and is confident that he can adjust in a relatively short period of time.

The latter nodded and indicated that he should just listen to the pilot.

Although this flight carried light fuel, thanks to the large fuel capacity of the J-11, it was more than enough to complete the test flight. ,

Hearing this answer, the commander looked back at Chang Haonan who was standing behind him, obviously seeking advice.

“Just listen to the pilot.”

Chang Haonan put a hand on the opponent's shoulder and said in a deep voice:

“The performance of this engine has been greatly improved. It's normal for you to not get used to it when you first get started, but there won't be any big problems.”

(End of this chapter)

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