Chapter 1400 The ground test conducted in advance
Half a month later.
The western suburbs of Rongcheng, Factory 132.
The No. 1 assembly workshop in the night is still brightly lit, and two black and gray-painted J-20 verification aircraft are lying quietly under the dome of the interweaving argon pipeline.
Yang Wei took off his oily gloves and glanced at the newly installed turbofan 10G tail nozzle at the wing root of No. 2003. The slender gray shell was filled with the unique cold and hard texture of metal in the light, which was in sharp contrast to the turbofan 10A, which was shorter in length and bright silver in the upper tail nozzle of No. 2001 next to him.
The subtle differences in appearance are naturally just appearances. The core reason for replacing the new tail nozzle is that the old model may not be able to withstand the higher temperature tail flame under the state of overburdening, and adapting to plasma generators that have never been seen before.
As for the change in length, it is simply to optimize the flow characteristics of the tail flame.
"Old Liu, remember to check the settings parameters of the front edge vibration probe of the fan front edge."
While commanding Liu Yongquan not far away to carry out the next step, he picked up the ballpoint pen at hand and made a hook after the penultimate item listed on the form:
"Although we did not test the aerodynamic this time, the ground resonance frequency must be strictly aligned, so that many things can be done before the interview flight."
Liu Yongquan was squatting carefully on an operating frame extending above the aircraft at this time. Several black signal lines extended behind the operating terminal in front of him, connected to an opening above the back of the aircraft: "The average difference between the amplitude parameters and the standard input signal is 0.33 microns, and the maximum difference is 0.45 microns, both within the allowable range. I will start measuring the frequency data immediately..."
The voice was vaguely trembling.
As an aerospace engineer, he rarely needs to perform such high-altitude operations.
The surrounding railings and safety ropes at the waist can provide safety, but they cannot provide a sense of security.
Moreover, compared to being injured after falling down, what he was more worried about is that after hitting the plane, the two relatively fragile composite materials between the No. 17 and No. 18 will be damaged.
Although the ground staff seems to be able to step on the plane without restraint on weekdays, their movable areas are actually strictly restricted.
Skin materials in some specific parts are specialized in tensile strength, but may not have strong shear resistance. If you step on them rashly, you may cause damage.
At the same time, the truss crane on the top of the workshop moved slowly, embedding the last set of fiber optic sensors into the skin mezzanine on the back of the No. 2003 machine.
In the cold wind in the winter night, dozens of technicians shuttled between the fighter jets and equipment, tying each process like precision gears, and assembled the No. 2003 machine as planned, it would take more than a month to compress it into fifteen days and nights.
Originally, since the first flight was not in a hurry to fly in 2003, the production task was relatively relaxed.
But considering Liu Yongquan's urgent needs, Yang Wei decided to give some help within his ability.
However, the first flight node of new aviation equipment, especially the fourth-generation fighter jets, is a major event, and even the chief designer does not have much say in this matter.
The latter therefore decided to advance part of the ground test process of No. 2003 to shorten the first flight interval between the two verification aircraft.
Fortunately, the overall structure of No. 2003 is not much different from No. 2001, and the basic work intensity in the previous period was not high, so even if the construction period was shortened by half, it was still easy.
"Okay!"
Fifteen minutes later, Liu Yongquan finally returned to the ground along the ladder, took off the safety rope and breathed a sigh of relief:
"All the sensors related to the engine, including the backup equipment, have completed the test to ensure stable and accurate data output!"
Perhaps to cover up his embarrassment of being a little weak, he deliberately increased the volume a lot when he said this.
Yang Wei nodded, not exposing the other party's little thoughts, but picked up the pen and ticked it behind the last item of the form, and then handed the folder and the pen to the other party:
"Check it out. If there is no problem, sign the letter under my name, and then you can prepare to transfer to the test station in the next time window."
Hearing this sentence, a light flashed in Liu Yongquan's already slightly tired eyes.
According to regulations, the transfer of aircraft between different workshops can only be carried out at a specific time window at night.
The overnight transfer today means that the test can be started tomorrow during the day.
But then a hint of worry emerged, looking at the No. 2001 machine a little further away that had completed the indoor testing process:
"Old Yang, I saw that when the No. 01 aircraft was tested a few days ago, it maintained its temporary configuration in its first flight state. It was much more fragmented than the No. 03 aircraft, and it would not affect the results of the control variables, right?"
Yang Wei was checking the personnel arrangement table for the transfer. Hearing this, he shook his head:
"The extra sensors will only affect stealth performance and part of the aerodynamic performance. As long as these two aspects are not involved, other tests can still be carried out as usual... Moreover, the landing gear will be fixed with an electromagnetic lock throughout the test. Even if there are some slight differences in the center of gravity or structure, certain compensation can be made based on the parameters of the electromagnetic lock."
In fact, Liu Yongquan also knew that these processes should be considered familiar to his colleagues in the aviation industry. But after all, it was the first time to follow the installation test throughout the whole process, so it is inevitable to pay more attention to these details...
...
When the first ray of morning light penetrated the high windows of the factory, Yang Wei finally announced the start of the test.
The on-site commander immediately began to issue specific operation commands, "Starting engine test, dual cooling rotation."
"Oil circuit system test, fuel oil pump start."
"Prepare to ignite, maintain the slow state first"
As the operator in front of the console gently pushes the throttle valve, the unique low hum of the turbofan 10G oscillates in the confined space.
In the backstage data monitoring room further away, Liu Yongquan stared at the flow field temperature model given on the screen next to him -
The engine in idle state will not show a tail flame visible to the naked eye, but this does not mean that the high-temperature gas gushing out from behind the tail nozzle does not exist.
The most new ⊥小小小小小小小小小小小小小小小小小小小小小小小小小小小小小小小小小小小小小小�
With the help of infrared imaging sensors and pressure field distribution sensors, the flow field conditions under this condition can still be basically accurately restored.
Of course, as a fully tested model, it is almost impossible to have any problems at low speeds.
So the atmosphere at the scene was relatively relaxed at this time.
However, a relatively young aerospace engineer suddenly asked: "Why does the infrared imaging signal display relatively uniform temperature distribution, but the 90° direction signal has the strongest signal on the ring distribution diagram of the radiation signal? Will it be..."
He originally wanted to say whether it was because of the engine assembly problem that caused high-temperature gas to overflow from the side.
But such an outrageous speculation was denied by him in the next second, after all, everything seemed to be normal on the infrared imaging image.
This sudden shout made everyone present shudder, but after hearing the question, he immediately relaxed.
Before Yang Wei spoke, Liu Yongquan took the lead in patting the other person's shoulder and signaled to be calm: "The infrared test of the whole machine is different from our aeroengine test. The circular distribution map measures the radiation flux, and the radiation in all directions is relatively uniform when the engine is just started. The final result is naturally the highest side value with the largest surface area projection... In fact, if it is a 540° stereoscopic test, the signal data on the top will be stronger."
As if it was confirming his statement, due to the gradual accumulation of heat inside the engine, the signal intensity in the 180° direction, that is, the positive tail gradually increased, pulling the entire schematic into a shape similar to a half-face shield.
The little commotion caused by the young man quickly subsided, but everyone still had to wait for a while to let the idle data go into stability.
At this time, Yang Wei seemed to suddenly remember something and looked at Liu Yongquan next to him: "Old Liu, I wonder if you have any impression that when the J-10 was conducting the ground start test for the first time, the debris inside the body almost broke the engine..."
The latter recalled slightly:
"When did the entire aviation industry company carry out major quality rectification?"
At that time, the two sides had not yet separated, and Liu Yongquan and others were seriously troubled for a long time, so they were deeply impressed.
Yang Wei nodded. "I heard that it was the problem that Mr. Chang discovered at the beginning?" Liu Yongquan was not at the scene at the time, but Lin Hui, the engineer who volunteered to enter the air inlet to check the engine condition, is now one of his important assistants, so many details have been heard from the latter.
Yang Wei was a little surprised, but he changed his words quickly: "Yes, and finally solved the problem, Mr. Chang designed a special cleaning mandrel on site to clean the dead zone inside a one-way trap."
Now, it really touched Liu Yongquan's knowledge blind spot:
"There is still this?"
"That's...so I always thought that Academician Chang would stay with our aviation side after the separation."
"..."
At this moment, a new voice from the on-site commander sounded in the communication system: "Increase the speed..."
As the engine operating conditions gradually approached the military thrust, a light blue airflow spiraled out from the serrated tail nozzle, and a perfect Mach ring was outlined in the air duct behind the aircraft.
(This chapter ends)