Chapter 1302 Must Surpass F22!

That evening.

Located in the large conference room on the top floor of Building 611.

More than half of the core backbone of the fourth-generation fighter research and development team are gathered together, with two summaries of test results placed in front of each of them.

Although it is a summary, because aerodynamics and microwaves are of great importance and can be said to be the two aspects that determine the key performance of a new generation of fighter jets, even after being refined, they are still two thick volumes.

More than a dozen printers in the archives worked almost until they started to smoke in the afternoon, barely making it in time for this meeting.

Of course, some of the key content is also displayed on the big screen at the front.

Lin Jihong was sitting in the first position on Yang Wei's left hand, introducing the corresponding part to everyone.

RCS is never a specific number. The "RCS value" that people usually see in data is often just the ideal situation at a specific angle, or the average result within a certain angle range.

To truly objectively demonstrate the stealth performance of an aircraft, it is necessary to use an expression similar to a physical field to present the reflected signal intensity at different angles in a three-dimensional space with the target as the center.

The presentation form of this result is quite complicated. Even with the report in hand, it is difficult to fully grasp the situation at once.

As the person in charge of tracking the entire microwave testing process, Lin Jihong can undoubtedly extract the key content in the shortest time.

"Everyone, based on the omnidirectional test results of the concept model in the microwave anechoic chamber, our basic solution can fully meet the performance requirements proposed by the aviation...especially within the conical range of 60° from the front, facing 3- In the 12GHz frequency range, that is, for radar waves in the X-band, S-band and part of the C-band, the radar reflection cross-section area is reduced by 2-3 orders of magnitude compared with the existing main models, effectively reducing the detectability when facing conventional radars. sex."

"This result is also basically in line with our theoretical judgment on the characteristics of electromagnetic signals in the preliminary research stage, that is, the canard wing in the same horizontal plane as the main wing will not have a significant adverse impact on the stealth performance of the front hemisphere, and combined with DSI The cocoon structure of the airway at the lip can more effectively shield the engine blades and reduce electromagnetic reflection at certain angles..."

As he spoke, he operated the mouse and dragged the 3D simulation on the computer, arriving at a slightly overhead perspective:

"It's here. It can be clearly seen that the intensity of the reflected signal near this angle has dropped abnormally compared to the surrounding area. Although it is only a very narrow range and has little impact on the overall reflection value, it can still illustrate our design ideas. correctness.”

Having said this, Lin Jihong paused for a moment, and then switched to another perspective:

“In addition, although the length and size of the aircraft are large, the left and right hemispheres and the radar reflection areas from directly above and below are inevitably relatively large, but it is still slightly better than our previous expectations, and it can also be achieved through reasonable design of the aircraft. The body structure and shielding relationship are further optimized..."

"..."

As the chief engineer, Yang Wei himself had read most of the phased reports, but he still followed Lin Jihong's introduction and took notes carefully.

After this part of the content was over, Kong Chengan, another deputy chief engineer sitting opposite the latter, suddenly stopped writing, raised his head and asked:

"Old Lin, what you just mentioned are all radar reflections in a static environment... So what will happen to the results if each wing surface, especially the full-motion vertical fin and canard wing, are moved?"

Because it is an internal meeting of the design office, the format is relatively casual, and there is no need to wait for the final unified question-and-answer session.

Lin Jihong was slightly stunned:

"We are just testing a conceptual model. The wing surface of the model being tested is incapable of movement, so we are unable to provide such detailed data for the time being..."

After about half a second, he added:

"But if the action surface changes significantly, it means that the aircraft is undergoing violent maneuvers. According to the qualitative results of previous studies, this situation will definitely lead to an increase in the radar reflection cross-section, such as what happened last year off the coast of Zhejiang and Fujian. Afterwards, analysis of that confrontation revealed that the most obvious signal detected by the opponent's F22 formation occurred during the transition from level flight to climb..."

"Well..."

Kong Chengan touched his chin, looking thoughtful.

Just when Lin Jihong felt a little strange, Yang Wei interrupted in advance:

"Lao Kong, are you worried about the introduction of active control technology?"

"yes……"

Kong Chengan nodded:

"According to the wind tunnel test results, the lateral stability of our solution is somewhat insufficient. If we want to ensure flight safety without increasing the number and area of ​​stabilizers, we must consider incorporating active stability control into the flight control. , improving the heading instability angle of attack through high-frequency feedback on the action surface.”

"However, the operation rules of relaxing the static stability design are seriously non-linear, and the action surface of the fully moving wing is the same as the stabilizer surface. The continuous opening and closing of the control surface will affect the stealth performance of the flying wing layout aircraft during cruising. This is also In the design process we have to..."

Compared with traditional aircraft that only need to consider aerodynamics and structure in the appearance design process, the research and development of fourth-generation fighter jets adds a dimension of electromagnetic reflection, which not only increases the technical difficulty, but also makes the organization and work of the technical team more difficult. The method has changed.

Anyone who has ever done a project knows that adding even one constraint will double the complexity of the system.

What's more, now a constraint area is directly added.

There are hundreds of conditions.

Check out the 16-9 book bar and see the correct version!

Yang Wei raised his hand and pressed it down, interrupting the other party's speech:

"This problem cannot all be solved by the flight control system. At present, our understanding of airfoil flow is still insufficient. Active control technology can only be used as a backup. Fundamentally, we still need to ensure that the aerodynamic design itself has sufficient static stability, so The simplest way is to add an aerodynamic stabilizer...such as a ventral fin or tail fin at the expense of a certain side and rear stealth performance."

This idea instantly aroused Lin Jihong's fierce reaction.

Of course, after all, he was facing the project chief engineer, so he couldn't really quarrel with him.

So he thought quietly for a moment, and then suggested:

"Mr. Yang, in the final analysis, this problem is because we applied too radical boundary layer separation control technology on the fuselage front body, which resulted in the lateral heading failure after the combination of the canard wing and the side wing failed within a certain angle of attack range. The stability is suddenly reduced, and once instability occurs, the normal heading control surfaces such as the vertical tail lose efficiency because they are in the low-energy wing body vortex wake, and cannot respond in time. "

"Compared with adding an additional aerodynamic stabilizer, why can't we reduce the area of ​​the side strip between the canard and the main wing? This will not affect the stealth performance, but also reduce the probability of instability... I have also seen the previous Wind tunnel test results show that the current supersonic lift coefficient of this configuration is almost overflowing. Even if it is weakened a little, it will not have an impact on the overall performance..."

Faced with this question, Yang Wei was silent for a moment:

"This is Party A's request..."

He also seemed a little distressed:

"In terms of supersonic maneuverability, it must surpass the F22!"