There is no doubt that yf-22 is the predecessor of f-22.

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

In this project, Lockheed Martin is the main contractor, responsible for designing most of the fuselage, weapon systems and final assembly mitigation, while the planning partner Boeing provides wings, rear fuselages, avionics integrated systems and training systems. At least as far as Alice knows, their allocation should be like this.

But the current actual situation has somewhat deviation from her memory, that is, Lockheed is also responsible for the avionics system. Of course, such situations like this that will occur as long as there is a slight deviation in the negotiation process will certainly not surprise Alice. Compared to knowing the comprehensive details of the entire project, this subtle difference is simply insignificant.

What Joseph, the project's relevant person in charge, is the relevant data on the products they are currently using to bid for, yf-22.

First of all, this new fighter, which is planned to be a fifth-generation fighter, has a maximum speed of Mach 24, a maximum lift of 200,000 meters, and a combat radius of about 650 to 700 kilometers. As for its weight, in principle, the lighter the better, but as a representative of heavy fighter jets, its maximum take-off weight is still as high as about 22 tons.

"During the development process, we have learned a lot from the technology and experience of f-117a because its stealth performance is excellent. At the same time, we also focus on overcoming the disadvantages of its fuselage composed of multiple oblique cone surfaces, and the cockpit's aerodynamic performance is not ideal, with large resistance, and can only do subsonic flight."

Speaking of this, seeing Alice just nodding, Joseph couldn't help but stop.

"Ask you, Alice, although you are an expert in computer programming, you can understand all of what I said?"

In order to avoid wasting your efforts and to better organize the next language, Joseph felt it was necessary to ask.

"Of course I can understand."

Alice could guess what Joseph was hesitating and smiled and said, "I studied college physics by myself as early as ten years old, and what you are talking about now is not a particularly professional thing. Please continue."

Seeing Oren nodding to him and smiling slightly, Joseph had to continue speaking.

"So, based on the f-117 model, we designed the yf-22 nose into a pyramid shape, and the two air inlets are installed along the lower incline of the pyramid, and the air inlet section is parallelogram, which is different from conventional aircraft. However, at this point, we need to make some choices. Although the stealth effect of the air inlet installed under the wing is far less than that of the wing, it is very conducive to improving the aircraft's large angle of attack maneuverability."

"This is a problem with the nose and air intake. As for the wings, we use a trapezoidal wing with a large root-tip ratio, that is, a trapezoidal wing with a larger wing root and wing tip ratio, with a sweep angle of 48 degrees ahead and a sweep angle of about 17 degrees behind the trailing edge. Choosing such a wing is conducive to highlighting the maneuverability of the aircraft, improving the aircraft's supersonic cruise capability, and meeting the needs of stealth. At the same time, in order to reduce the interference between the flat tail and the upright tail, we designed to tilt the double upright tail only 27 degrees outward, which is... very small."

Whenever there was a professional term in the corridor, Joseph carefully adopted a more understandable statement, carefully observing Alice's expression, for fear that she would appear confused or pretend to understand if she didn't know.

Fortunately, what made him feel relieved was that the girl who suddenly appeared seemed to have heard it. From her eyes, she was really thinking about her introduction seriously, rather than pretending to be deep.

"As for the pilot cockpit, we set it to be bubble-type and has a good vision. At the same time, the flat tail, tail brace, binary spout and tail cone on the aircraft have a non-standard zipper shape, which is mainly to scatter enemy radar waves shot from behind."

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

"Sorry, interrupt."

Alice raised her hand and signaled: "Please explain it, is this thrust vector vent good? "

Asking if you don’t understand, this behavior made Joseph feel more relieved, and every engineer present couldn’t help but breathe a sigh of relief. Not bad, not bad, at least judging from the current situation, this girl who was suddenly invited into the house by the boss will be an outstanding partner.

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

There is no doubt that military aircraft research and development is a project that integrates technologies in multiple fields. When countless technologies are concentrated on a mere aircraft, each seemingly irrelevant combination has an inseparable relationship with each other.

From the shape of the aircraft, the design reasons for the shape, to the specific parameters of the aircraft and the engine, and what technology the engine adopts, all this information will be closely related to the onboard avionics system. It can be imagined that if the person who wrote the system did not understand the performance of the aircraft, his works would not be suitable for this aircraft at all.

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

"The specific impact of this control... please tell me in a little detail, okay?"

"It is to turn part of the thrust of the engine into a control force."

Joseph answered her readily: "This approach can greatly reduce the radar reflection area. 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 control force to operate, which increases the maneuverability of the aircraft."

"And, because the manoeuvre force is generated directly, and the magnitude and direction are volatile, this increases the agility of the aircraft, so we can appropriately reduce or remove the vertical tail. It is obvious that the fewer parts, the harder it will be to be discovered by radar, which can reduce the drag of the aircraft, reduce the structural weight, and even reduce costs."

From every 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 comparing any documents. In general, the general content alone took him an hour.

The real time of the entire meeting was much longer than this. Whenever Joseph talked about some key points, Alice would ask questions in a very targeted manner. Furthermore, as the number of questions continued to increase, the frequency of thirty people in the audience exchanged their eyes higher and higher.

There was an obvious very simple question, and Alice did not mention any of them. Every question she asked was very introductory, and often required Joseph's long speech to explain it thoroughly. During the whole process, a very wonderful situation was gradually discovered by everyone.

At the beginning, Alice was puzzled by some very critical and unusual technical terms, such as the "thrust vector technology" that was originally asked. However, as the introduction continued, Alice's question gradually changed from the incomprehension of the noun to a rhetorical attitude.

"Why should we take this angle? Isn't that angle better?"

"The area of ​​the engine blades must be related to the thrust, right? Too wide and too narrow have gains and losses. All we need to do is to take the intermediate amount, right? So, since this engine uses this size to be the effect, which size is that effect, would it be better if this size is used?"

These questions seem to be raised inadvertently, but there are thirty people present, and Joseph is the only one who keeps talking. When he keeps talking about these well-known information, the idle people naturally can't help but think about it. The views raised by Alice seemed to make sense.

Even Joseph himself, facing Alice's one question after another, was even more stunned.

Why is this angle, not that angle?

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

It seems that I just talk about the number casually, but when I think about it carefully, it seems that this number... is the most appropriate number!

The meeting officially started at 9:30. When the time was about to be lunch, Joseph and Alice had quietly changed their Q&A relationship.

"Just talk about invisible paint. You ask me what are the ways to reduce costs, right? The direction of nano-coating is correct, but are you too obsessed with the elements that look expensive? Think about diamond, just by changing the order of carbon atoms, you can form such a solid substance. If we can find relatively cheap alternatives to stealth paint, isn't it the best price reduction range?"

"Don't, don't tell me about making money. I don't understand how small profits are made but quick turnover. Calculated by the paint you told me, the final cost of this aircraft must exceed 100 million. With various post-production costs, one aircraft costs 300 million to 400 million! At such a expensive price, selling one aircraft or two is a big profit, but you can only sell one or two aircraft!"

"Hurry and try that element for me! Yes, that element, oh, don't be obsessed with your element. Please see if the chemical book is good? My element is twice as cheaper than your one. Use my element and try this as a substitute. I don't believe that the cost will not be reduced!"

At the end, Alice slapped the table with anger, as if Joseph was a primary school student who didn't even know one plus one. Why didn't he find the obvious answer?

Yes, why didn't you find it?

Joseph thought of Alice's suggestion with empathy. It seemed, as if, almost, that element she proposed could really be used as a replacement for reducing costs.

So, creativity and inspiration are sometimes really disgusting.

Knowing means knowing, not knowing, not knowing.

Why didn't I expect it?

Joseph was really depressed.
Chapter completed!