Chapter 1401 A Little Problem

While the engine gradually changes its operating state, the accumulated relevant data is also being processed synchronously and output to the rear terminal later.

In the past, due to insufficient performance of background computers, data collection and processing were usually divided into two independent processes in order to ensure reliability.

Apart from the part that can be directly distinguished by the naked eye, most of the information can only be obtained after a period of time after the test is completed. In addition to the subsequent manual analysis and collation, even if everything goes well, the time required for each set of tests will be extended to several days or even weeks. Once there is a problem and rework is required, it often takes months.

Therefore, after Project No. 20 was officially approved, Yang Wei's first funding application report was to comprehensively upgrade the equipment in the test workshop, which ultimately shortened the cycle by more than three quarters.

For example, now they can view the operating characteristic curves given by a series of sensors while the engine is running.

"Fortunately, there is no problem with the flow distribution of the air film cooling system, and the operating temperature has not exceeded the safety threshold."

Liu Yongquan lowered his head and stared at the data on the B-2 monitor.

The pointer representing the temperature value trembled and moved closer to the clockwise direction, but it was as if it had hit a barrier and was always at a considerable distance from the red area on the far right.

After relaxing a little, he continued:

"The initial version of the plan was calibrated according to the bench data. Under military thrust, the cooling airflow was distributed to the turbine blades and the combustion chamber wall in a ratio of 73:27. However, it was later re-calibrated based on the Trent 900 installation and operation data provided by General Chang. After considering the actual situation of installation inside the fuselage, the actual distribution was changed to 65:35 in the final stage..."

The 611 Institute is not specialized in engine design, but the other technicians from the 606 Institute who came with them are well aware of this.

Therefore, Liu Yongquan's words were more like an attempt to calm himself down rather than an explanation to others.

In terms of engine and flight matching, the biggest difference between the J-20 and the two third-generation aircraft is that, whether it is the J-10 or the J-11, because stealth modification is not taken into consideration, a considerable area of ​​the engine outer casing is directly exposed to the outside, or at most a layer of protective bushing is added.

Stealth aircraft need additional skin to completely cover the entire engine structure except for the tail nozzle.

In addition to bringing additional structural weight, it also puts forward new requirements for heat dissipation methods.

This cannot be simulated in any test before installation.

At this time, Yang Wei's attention was focused on the force data of the engine's fixed ring and the vibration data of the fan and compressor at different speeds:

"I think that when we get to the prototype stage, we need to further strengthen the design of the engine fasteners... The increased thrust has put a greater burden on the fuselage than expected. Although it will not directly affect flight safety, if it works for a long time under conditions close to the safe load, it will inevitably be detrimental to its lifespan."

After saying that, he raised his head and turned to Liu Yongquan, with a slight smile on his face:

"The vibration characteristics of WS-10G are almost identical to those of WS-10A, with only a slight difference in amplitude, which saves us a lot of trouble in adjusting the structure."

"That is……"

The latter focused his sight into the distance. Through a layer of glass curtain wall, he could see the slender and strong No. 2003 aircraft bowing slightly forward because its landing gear was fixed by an electromagnetic lock, like an angry dragon ready to pounce at any time:

"After all, the overall design of the core engine has been based on the fourth generation since the beginning. It's just that our materials and process levels were not up to standard ten years ago, so we had to downgrade the WS-10A configuration."

At this point, his tone suddenly changed:

"To be honest, although I have been involved since the aerospace battle, it was not until I took over the design of the WS-10G that I clearly felt how extreme the design of this core engine was..."

Because there was no noteworthy data at the moment, Yang Wei also cast a curious look.

Liu Yongquan shrugged helplessly:

"I once tried to use the experience of designing the M88-3 and SeA650 engines to modify part of the rotor blades of the high-pressure compressor. As a result, I found that even if many parameters were slightly adjusted, it would not be possible to achieve compatibility between the second-stage fan and the third-stage fan. Even if we only consider the case of adapting to the third-stage fan, there is almost no obvious upgrade space."

当初为了提高推重比，常浩南在完成3-7-1-1的基础核心机结构之后，又给涡扇10A/B减去了一级风扇，变成了相对不太常见的2-7-1-1构型。

Although similar operations are not the first in the history of human engine design, the few precedents have not been very successful.

For example, the WS-5 with a rear fan.

It is quite rare to be able to do it without any trouble like the WS-10...

……

After the engine ran at maximum speed for 30 minutes, long-suppressed cheers broke out in the backstage testing room.

The first round of startup tests did not include the afterburner portion.

Therefore, after the two engines reached and maintained military thrust for a period of time, the testing of the power part itself came to an end.

If it is an ordinary model, then all we have to do is wait until nightfall and tow the plane back to the final assembly workshop to check whether the testing process has caused any hidden dangers.

But the combination of the J-20 and the WS-10G has an additional mission.

Yang Wei once again came to the microphone and gave new instructions to the operator downstairs:

"Inject ionized seed gas into the combustion chamber and start the plasma generator!"

Soon, the indicator light marked with "Ar" on the status display turned from yellow to green, indicating that high-pressure argon gas had begun to be injected into the plasma generator.

The color of the tail flames emitted by the two turbofan 10Gs also seemed to deepen slightly, as if the afterburner was turned on, showing a more obvious blue-purple color.

It's just that the light isn't that bright yet.

"Turn on the magnetic control device, working mode... default one."

Yang Wei is still a little unproficient in this plasma stealth system.

In fact, the sheath distribution effect can be even better if the plasma control strategy is fine-tuned for each flight condition.

But obviously we can't expect fighter pilots to write code in the cockpit while flying the plane, so we can only preset four default control methods according to typical conditions, and then automatically or manually switch to the most appropriate one.

The default one corresponds to the normal level flight state.

Sure enough, a strange light blue glow quickly appeared at the tail of Unit 2003.

In the infrared imager, the pure white area representing the high thermal radiation signal is spreading from the tail and ventral fin toward the front fuselage at a speed visible to the naked eye.

"Wait, this infrared signal..."

Yang Wei clenched his hands into fists, but still resisted the urge to stop the test.

On the one hand, he believed in Chang Haonan's calculations, and on the other hand, he also believed in his own plane.

About half a minute later, the data analyst looked up and gave the result:

"Report: The temperature sensors installed on the trailing edge of the vertical tail and the ventral fin did not sound an alarm. The highest temperature point only rose by 15 degrees compared to before, and will not have a significant impact on the stealth coating..."

At this point, he even began to doubt his own judgment.

But since Yang Wei didn't stop, he had no choice but to continue:

"On the contrary, the temperature of the skin in the middle of the fuselage has risen significantly, and the data from the 17D sensor has increased by 50 degrees..."

The maximum operating temperature of the new stealth coating is above 240C, and the temperature resistance can reach 300C. It will not cause irreversible damage due to this temperature rise. At most, it will need to be re-coated more frequently.

What Yang Wei was most worried about was the other part:

"Just tell me about the intake lip!"

In order to solve the century-old problem of the narrow working width of the DSI air inlet, they very boldly used partial flexible skin materials on the cocoon structure.

This new thing's high-temperature tolerance is much worse than stealth coating, and it will also directly affect flight safety.

The interrupted technician swallowed nervously, but fortunately he still gave the result in time:

"From the front wing forward, there is basically no impact..."

"call--"

Even though it was only a short minute, when Yang Wei let go of his hand again, his palms were already sweating.

"So, why—"

He wanted to know why the heat signature picked up by the infrared imaging system was so pronounced, but the temperature given by the skin sensors showed almost no change.

But Liu Yongquan had already anticipated this problem and didn't even wait for him to finish:

"I don't quite understand the specific theory, but with the help of a magnetic field, the energy of the plasma can be isolated within a certain space."

Afterwards, perhaps because he felt that this explanation was a bit abstract, he added a metaphor he had heard from Han Chenfeng before:

“Like a tokamak.”

Yang Wei didn't expect that his plane would be related to nuclear fusion, but after thinking for a moment, he decided not to worry about these details.

But the subject changed:

"For fighter jets, in addition to heat insulation, there is actually another problem."

He looked at the almost blank screen:

"The radar stealth problem has been solved, but such a high surface temperature doesn't seem to be good news for infrared stealth..."