There is no doubt that the YF-22 is the predecessor of the F-22. Pen @ fun @ pavilion wWw. ｂｉｑUｇE。 ｉｎｆｏ

The F-22 Raptor fighter is jointly developed by Lockheed Martin and Boeing, the world's first single-seat twin-engine high-stealth fifth-generation fighter, which entered service with the US Air Force in the early 21st century to replace the F-15 Hawk fighter, the main aircraft of the fourth generation.

For this project, Lockheed Martin is the lead contractor responsible for designing most of the airframe, weapons systems and final assembly mitigation, while program partner Boeing provides the wings, rear fuselage, avionics complex and training systems. At least as far as Alice knows, that's how their distribution should be.

It's just that the current actual situation is somewhat different from her memory, that is, the avionics system is also in charge of Lockheed. Of course, the slightest deviation in the negotiation process would not surprise Alice, of course, and this subtle distinction is nothing more important than knowing the comprehensive details of the entire project.

At present, the person in charge of the project, Joseph, introduced the relevant data of the product they are currently using for bidding, YF-22.

First of all, this new fighter, which is planned to be a fifth-generation fighter, is designed to have a maximum speed of Mach 2.4 per hour, a maximum ceiling of 200,000 meters, and a combat radius of about 650 to 700 kilometers. As for its weight, in principle, of course, the lighter the better, but as a representative of a heavy fighter, its maximum take-off weight is still about 22 tons.

"During the development process, we borrowed a lot of technology and experience from the F-117A, because its stealth performance is very good. At the same time, we also pay attention to overcoming the shortcomings of its airframe composed of multiple oblique cones, and the aerodynamic performance of the cockpit is not ideal, the drag is too large, and it can only do subsonic flight. ”

Speaking of which, seeing that Alice just kept nodding, Joseph couldn't help but stop.

"I would like to ask, Alice, although you are an expert in the field of computer programming, but you are also in the development of aircraft...... Do you understand what I'm saying?"

In order not to waste his efforts, and to better organize the following language, Joseph felt it compelled to ask.

"Of course I understand. ”

Alice could guess what Joseph was hesitating, and said with a smile: "I taught myself college physics when I was ten years old, and besides, what you are talking about now is not something particularly professional. Please go ahead. ”

Seeing that Oron also nodded to himself and smiled a little bitterly, Joseph had no choice but to continue.

"So, based on the shape of the F-117, we designed the nose of the YF-22 to be pyramidal, and the two air intakes were installed along the downward slope of the pyramid, and the air intake section was parallelogram, which is different from conventional aircraft. However, at this point, we need to make a trade-off, although the stealth effect of the air intakes under the wing is far less good than that on the wing, but it is extremely conducive to improving the aircraft's maneuverability at high angles of attack. ”

"It's a matter of the nose and air intakes, and as for the wing, we used a large root-to-tip ratio, which is a trapezoidal wing with a large root-to-tip ratio, with a leading edge sweep angle of 48 degrees and a trailing edge sweep angle of about 17 degrees. The choice of such a wing is conducive to highlighting the improvement of the maneuverability of the aircraft, increasing the supersonic cruising capabilities of the aircraft, and meeting the needs of stealth. At the same time, in order to reduce the interference between the flat tail and the vertical tail, we designed the double vertical tail to be tilted outward only 27 degrees, which is ...... Very small meaning. ”

Whenever he was talking about technical terms, Joseph carefully adopted more intelligible terms, carefully observing Alice's expression, lest she appear confused or not pretending to understand.

Fortunately, to his relief, the girl who came out of nowhere seemed to really listen. From the look in her eyes, she could see that she was really thinking seriously about her introduction, rather than pretending to be deep.

"As for the pilot's cockpit, we made it bubble-shaped, with a good view. At the same time, the rear edge of the plane's flat tail, tail brace, binary nozzle and tail cone all have irregular jagged shapes, which are mainly used to scatter enemy radar waves from behind. ”

"In terms of power source, we plan to adopt thrust vectoring nozzle technology, so in terms of cost, we ......"

"Excuse me, interrupt. ”

Alice raised her hand and said, "Please explain, what kind of technology is this thrust vectoring nozzle?"

Asking if you don't understand, this kind of behavior can't help but make Joseph more relieved, and every engineer present can't help but breathe a sigh of relief. Yes, yes, at least for now, this girl who was suddenly invited into the house by the boss would be an excellent partner to work with.

"Thrust vectoring refers to the thrust component generated by the deflection of engine thrust through a nozzle or tail jet. This technology can replace the control surface of the original aircraft, or enhance the control function of the aircraft, and can control the flight of the aircraft in real time. ”

There is no doubt that military aircraft research and development is a project that integrates multiple fields of technology, and when countless technologies are concentrated on a single aircraft, each seemingly unrelated combination has an inseparable relationship with each other.

From the shape of the aircraft, the reasons for the design of the shape, to the specific parameters of the aircraft and engines, and what technology the engines use, all of this information will be closely related to the onboard avionics system. It is conceivable that if the person who wrote the system did not understand the performance of the aircraft, his work would not have been suitable for the aircraft at all.

Therefore, the atmosphere of this meeting became more relaxed as Alice asked questions one after another.

"The specific impact of this control...... Could you please elaborate a little bit?"

"It's about turning part of the thrust of the engine into maneuvering power. ”

Joseph replied cheerfully: "This can greatly reduce the radar reflection area, and at the same time, no matter how large the angle of attack and how low the flight speed, the aircraft can use this part of the maneuvering force to maneuver, which increases the maneuverability of the aircraft." ”

"Also, because the direct maneuvering force is generated and the magnitude and direction are variable, this also increases the agility of the aircraft, so we can also reduce or remove the vertical tail appropriately. Obviously, the fewer parts there are, the harder it is to be detected by radar, and it also reduces the drag of the aircraft, reduces the weight of the structure, and even reduces the cost. ”

From each design of the aircraft to the specific reasons for each design, Joseph gave Alice the most detailed introduction to every detail of the entire aircraft without having to compare any documents. All in all, it took him a full hour of his time.

The real time of the whole meeting was much longer than that, and whenever Joseph said something crucial, Alice would ask very targeted questions. Then, as the number of questions increased, the frequency of exchanging glances among the thirty people in the audience also increased.

There are very simple questions, and Alice doesn't mention any of them, and every question she asks is very pointed, and often requires Joseph to explain at length to be thorough. And in this whole process, a very wonderful situation was gradually discovered by everyone.

In the beginning, Alice was puzzled by some very critical and very obscure technical terms, such as "thrust vectoring technology" in the first question. However, as the introduction continued, Alice's question slowly changed from incomprehension of the noun to a rhetorical attitude.

"Why this angle? Isn't that angle better?"

"There must be a relationship between the area of the engine blades and the thrust, right, too wide and too narrow, there are gains and losses, what we need to do is to take the middle amount, right? So, since this engine uses this size for this effect, and that size for that effect, wouldn't it be better if it used this size?"

These questions may seem to have been asked casually, but there were thirty of them, and Joseph was the only one who kept talking. When he kept talking about these well-known information, others who had nothing to do naturally couldn't help but ponder, and Alice's opinion seemed to be very reasonable.

Even Joseph himself, who was constantly faced with Alice's questions one after another, was more and more stunned.

Why this angle, and not that?

This area and that area are not good, but what about this one area?

It seems that it is just a random number, but when you think about it, the thirty people in this room seem to be ...... It's the most appropriate number!

The meeting officially began at half past nine, and when the time was close to lunchtime, Joseph and Alice, the relationship between the two had quietly changed.

"Let's talk about stealth coatings, you ask me if there is any way to reduce costs, right? The direction of nano coatings is correct, but are you too obsessed with those elements that look expensive? You think about diamond, but just change the order of carbon atoms to form such a strong substance. Isn't stealth paint the best price range if we can find a relatively cheap alternative to something as expensive as stealth paint?"

"Don't, don't tell me about making money, I don't understand small profits but quick turnover. According to the calculation of the paint you told me, the final cost of this aircraft must exceed 100 million yuan, plus all kinds of later costs, one plane will cost three or four hundred million yuan! Such an expensive price, selling one or two is a big profit, but it can only sell one or two!"

"Hurry up and give me a try with that element! Yes, yes, that element, oh, don't be obsessed with your element, please read the chemistry book, okay? The refining process of my element is twice as cheap as yours, use my element, and then try this as a substitute, I don't believe that the cost can't be lowered!"

In the end, Alice slapped the table with an angry face, as if Joseph was a schoolboy who didn't even know one plus one, so why didn't she find out the obvious answer?

yes, why didn't you find out?

Joseph thought about Alice's suggestion with empathy, seemingly, as if, almost, that element she proposed could really be used as a substitute for reducing costs.

So, creativity and inspiration are just disgusting sometimes.

To know is to know, not to know, not to know.

Why didn't you think of it?

Joseph was really upset. (To be continued.) )