Chapter 1305: R&D 1st Generation, Pre-Research 1st Generation

Zhang Pinsheng looked at the other people with a bad look on his face for a while.

Then, perhaps because he felt that it was not a good idea to continue the confrontation, or perhaps because he caught a glimpse of Chang Haonan's name on the first page of the document, he took the lead in breaking the stalemate, dragged the technical document next to him, and softened his tone a little:

"No matter from the technical or safety perspective, I cannot allow you to start the engine in the microwave darkroom... However, we have considerable experience in radar testing and may be able to come up with a feasible alternative based on your specific needs."

Except for Liu Yongquan who brought the information, everyone else was struck by the keyword "plasma stealth" in the summary, and did not even have time to read the key content that followed.

Now that Zhang Pinsheng reminded them, they all came to their senses.

Then there was the rustling sound of flipping papers.

Compared with aircraft general design units that have been studying stealth technology for nearly 20 years, the aero-engine field has basically only started to consider the issue of reducing signal characteristics in the last one or two years, and the research focus is still on infrared signals.

Therefore, the content relayed by Liu Yongquan may not be accurate.

It is more reliable to look directly at the written requirements document.

As expected, the document detailed the generation and control methods of the plasma sheath, as well as the original purpose of the test -

"When the engine and plasma generator are in operation, measure and compare the RCS (σ)-angle (θ) relationship curves corresponding to different magnetron algorithms, paying special attention to the changes in the tail of the aircraft (within the range of 80°-100°) to determine the volume coverage and frequency coverage accuracy of the magnetron plasma sheath..."

Zhang Pinsheng recited the last section word for word, then lowered his head and thought for a moment:

"In other words, the main purpose of this test is to make a comparison, and it does not particularly pursue the comprehensiveness of the values ​​themselves?"

Liu Yongquan nodded:

"The engine involved in the test is only a technical verification model improved on the basis of the WS-10A. It is not the final product that will be delivered to the fourth-generation fighter project, so the RCS result does not have much practical value. It only needs to verify the effects of several control schemes..."

At this point, perhaps out of concern that the other party might have over-understood him, he added:

"Of course, the deviation cannot be too outrageous. At least the order of magnitude must be correct... In addition, although it is not necessary to provide full-band sweep measurement covering L to Ka like the American lintek5000 system, it is also necessary to ensure that the wavelength of the test signal is selected between 2.5cm and 7.5cm, and the bandwidth cannot exceed 0.2cm..."

Before he finished speaking, Zhang Pinsheng's originally stiff expression obviously relaxed:

"If that's all, then I have an alternative plan..."

Everyone's attention, including Yang Wei, was drawn to him.

Even Zhang Pinsheng, who rarely saw big scenes, felt nervous for a moment:

"Cough-cough-"

He cleared his throat:

"Old Lin should know about this... In the early years, when we didn't have this large microwave darkroom and swept-frequency measurement radar, in order to ensure the large-scale outdoor omnidirectional scattering test of the J-7IIS and J-8IIS, we renovated a dynamic test bench on the top of the mountain behind the old park..."

Lin Jihong's eyes showed confusion for a moment, but he quickly reacted and turned to surprise:

"Hasn't that test bench been out of use for several years? And as far as I can remember, the electromagnetic signal source was a 342 radar removed from a warship. I'm afraid its bandwidth accuracy doesn't meet the requirements of this test?"

Zhang Pinsheng immediately explained:

"It's true that it hasn't been used for six or seven years, but don't forget that the test bench was not equipped with an aircraft turntable because of time constraints. Instead, a circle of tracks was laid around the fixed platform, and then the radar was installed on the track to orbit the aircraft..."

Liu Yongquan and Yang Wei did not experience the round of stealth technology verification in the 90s, but after the initial confusion, they quickly grasped the key.

"So... it still works now?"

Liu Yongquan asked with concern.

He didn't know much about radar, but he understood that the omnidirectional detection platform built on the top of the mountain meant that the test background was relatively clean.

After all, the atmospheric absorption of electromagnetic waves between 2.5cm and 7.5cm is relatively weak. Even if the test is not as good as a microwave darkroom surrounded by electromagnetic absorbing cones, it is at least similar to the actual environment.

Zhang Pinsheng nodded:

"The backend systems are all underground. Although they are a little outdated, they are all sealed in strict accordance with the rules and regulations. We just need to recheck and replace some necessary consumables. The only thing is that the broken radar we used before is definitely out of service due to the wind and sun. It will take some time to replace it with a new one."

Yang Wei also interrupted at this time and began to brainstorm:

"For a new radar, perhaps we can just dismantle a 1473... There's no need to contact the China Electronics Technology Group separately. Rongfei has a lot of them waiting to be installed on the aircraft. I can just sign my signature and transfer them over..."

However, Zhang Pinsheng waved his hand and rejected his proposal:

"Fighter radars ... or most modern search/fire control radars are broadband radars, which are not very suitable for testing requirements."

"That……"

Yang Wei's expression froze for a moment.

"We have several 5cm wavelength 172B precision measurement radars, which we used when doing track measurements for the Flight Test Research Institute in the first half of the year."

Zhang Pinsheng replied:

"Of course, because it is a conventional radar, it does not have the ability to directly measure the absolute value of RCS. However, it can use the relative measurement method, that is, using a small metal ball as a calibration body to obtain the relationship between the precise RCS value and the signal echo intensity. Then, based on the power or voltage ratio obtained from the target test, the reflection area of ​​the target can be calculated. The key is that the bandwidth is very narrow, which meets the requirements of RCS measurement..."

"..."

After some discussion, everyone looked at each other again.

This time, the atmosphere was no longer as tense as it was at the beginning.

"Director Zhang, how long will it take to complete all the tasks you just mentioned?"

Liu Yongquan asked:

"Factory 410 currently only has two modified WS-10A units. I need to schedule the transportation as accurately as possible..."

The design and development of the WS-10G is not urgent in the next few days, but Chang Haonan had previously specifically instructed that the relevant test parameters of the plasma sheath are related to other projects he has on hand, so he still has to calculate the test cycle.

"We don't really have much to do here, maybe a week to ten days..."

Zhang Pinsheng said this and looked at Yang Wei and Lin Jihong beside him:

"It mainly depends on whether Rongfei can fit their engine into the model..."

Yang Wei nodded:

"Even if the model is inserted, it cannot provide working conditions for the engine. It is better to directly modify a J-10S prototype, just like the J-7IIS, fix the aircraft on the test bench and start the engine directly..."

"..."

……

Half an hour later, the group left the meeting room happily.

However, after the meeting, Yang Wei and Lin Jihong called Liu Yongquan over again:

"Mr. Liu, please stay for now."

As the three of them deliberately slowed down their pace, they soon fell behind the large group of people.

"I just took a look at the document and noticed that the control method for the plasma sheath is to use the induced magnetic field equation to solve the induced magnetic field, combine it with the induced current to get the Lorentz volume force, and then add the correction term of the reaction electromagnetic effect to the turbulence equation to obtain the modified turbulence two-equation model, thereby simulating the classic Hartmann magnetofluid flow..."

In just a short period of time, Yang Wei extracted the key points, and he was able to do two things at once, which was enough to show how strong his ability was:

"So, is it possible to direct some of the plasma to the front of the aircraft, and then install magnetic control equipment on the outer edge of the wing or canard to reduce the additional radar reflection generated during the operation of the operating surface?"

As soon as he finished speaking, Liu Yongquan was still thinking, but Lin Jihong, who was walking on the other side, subconsciously stopped:

"Boss Yang, didn't you say at the meeting the day before yesterday that we should try to avoid using active control systems too frequently?"

"Now this project... is indeed the case."

Yang Wei smiled and nodded:

"But I have been thinking recently, what should the next generation of products look like after the fourth-generation aircraft enters service?"