After hanging up the phone, Li Jianguo smiled slightly, let out a long sigh, put down the mouse, got up, drove to Li Tianfeng's bedroom, and quietly opened the door.
Like the rooms of most adolescent boys, the walls of Li Tianfeng's room are also covered with posters of all sizes.
However, the difference is: most of the posters posted in Li Tianfeng's room are posters of various aircraft at home and abroad, including fighter jets, transport aircraft, and passenger aircraft.
Li Jianguo often asked his son: "Xiao Feng, what do you plan to do when you grow up?"
"Build a plane!"
When I was a child, I was "building airplanes". When I was in high school, I was "designing airplanes." After that, it never changed...
"Congratulations, Xiaofeng, you are finally one step closer to your dream!"
Li Jianguo glanced at the various professional books and magazines on the bookshelf in the room with great satisfaction, and closed the door with a smile...
A week later, when Zhou Yan was busy designing the drone's fuel tank, landing gear and overall load-bearing frame, the post office courier called.
"Li Tianfeng, if you have something big, go to the post office and pick it up yourself!"
Zhou Yan took a group of brothers from the dormitory and rushed to the post office.
When they arrived at the place, Zhou Yan finally knew how big the so-called "big items" were: the Hangfa manufacturing plant in Fengtian used standard Hangfa transshipment packaging when shipping. Although it was in corrugated boxes, it was
There is no shortage of shockproof and fixed equipment inside.
What's even more terrible is that in addition to one main engine and two spare parts, three complete engines, they also come with two sets of spare parts.
What surprised Zhou Yan even more was that Fengtian Aviation returned the engine for testing, and the test items were exactly the same as regular military engine test items.
"That's it..." Zhou Yan flicked the engine performance test report in his hand, "You don't need to test it yourself, you can directly import it into the electronic control system!"
Now that the engine is there, the next thing is the whole machine.
In order to achieve optimal maneuverability, Zhou Yan has reduced the weight of the entire machine.
The frame can be made of high-strength aluminum alloy, but the duct, blades, steerable intake and exhaust grilles and core outer skin of the ducted fan cannot be made of engineering plastics or carbon fiber...
…
What is the best thing to use?
Just when Zhou Yan was hesitant, Lao Wu seemed to see Zhou Yan's entanglement and asked cautiously: "Lao Liu, the best material for aircraft skin should be carbon fiber, right?"
"Yes, what's wrong?" Zhou Yan was a little surprised.
"Well..." Lao Wu was a little embarrassed to say, "I'm just a kid. A while ago, I imported a batch of carbon fiber materials from a foreign country in order to modify a sports car. It's just that I don't know what to do with this stuff, so the materials have been kept somewhere.
It’s useless…”
"Lao Wu, I really didn't expect that you are still the second generation of rich people?"
"Lao Wu, how do you plan to make up for the trauma you have caused to our young hearts?"
A group of roommates in the dormitory would give Lao Wu a verbal and written beating when they caught him.
Compared to other people who looked dark, Zhou Yan naturally knew a little bit about Lao Wu's family: this family was engaged in fine chemicals and had high added value, so they were naturally not short of money.
"Lao Wu," Zhou Yan thought for a while and said, "We can't use other people's things in vain. Let him make some more carbon fiber later, and we can help him modify the sports car!"
"Modified cars, Sixth, do you really dare to play with it!?" The boss was dumbfounded.
"Why don't you dare to play?" Zhou Yan curled his lips, "If you want to move, naturally move to the most confident place. After all, we are also learning aircraft design. If the drag coefficient of a sports car cannot be lowered, how can we design an airplane?
?”
"That's right!" The boss suddenly reacted, "The simulation software in your computer can be called an artifact!"
The processing of carbon fiber sounds very impressive, but in fact it is as simple as layering the carbon fiber and reinforcement materials into the mold, using vacuum to penetrate the binder, and finally using high temperature to form it.
Carbon fiber is available, but Zhou Yan still lacks molds.
"I have to do it myself!"
Funds are limited, and the overall size of the drone reaches an astonishing one meter two by one meter. Therefore, although it is modular assembly, the length of the mold is not less than one meter.
In order to save money, Zhou Yan found a woodworking factory near the capital and made a set of molds using elm wood.
After that, the six people in the dormitory began to work in groups: one group followed Lao Wu to make carbon fiber casings, fan ducts, grilles and blades, and the other group found people to process fuel tanks, landing gear and other accessories.
Zhou Yan went to the digital market with his boss to search for digital cameras and telephoto lenses. After finding the items, the two of them printed circuit boards, welded electronic components, burned electronic components, and programmed the electronic control system.
By the time the drone is assembled, it will basically be the end of April.
During the May Day holiday, a group of people in the dormitory had no plans to go out. Instead, they took the Dajinbei borrowed by Lao Wu and ran to Zhangjiakou with the drone and accessories.
A group of people simply don't dare to test fly in the capital. If they are not careful, they will be hit by missiles.
The test flight work was still carried out by Zhou Yan.
A group of people in the same dormitory only thought that Zhou Yan took the initiative to take over the test flight because he was familiar with the aircraft. They had no idea that the test flight work basically relied on experience and instrument flying.
Fortunately, Zhou Yan is an experienced pilot, and the built-in database of the UAV flight control system has already set a rough flight envelope in advance.
What Zhou Yan needs to do is to test the specific flight envelope and more detailed flight performance.
The aircraft's vertical takeoff and landing is mainly controlled by four fans, and there are two main ways to achieve the aircraft's forward and backward movement: large-angle steering, like the MV-22 Osprey, is controlled by the overall deflection of the four ducted fans; and small-angle steering is the same as the MV-22 Osprey.
Angle steering and pitching are mainly achieved by deflectable air intake grilles on both sides of the ducted fan inlet and outlet.
The overall attitude of the aircraft is converted into a digital signal by a fiber optic gyroscope arranged at the center of gravity of the aircraft. Moreover, the fiber optic gyroscope is also the attitude control mechanism of the telephoto digital camera in the drone's load bay.
For a whole week, the six people spent time on the grasslands of Zhangbei. When the flight test was completed and they returned to the capital, all six of them were unshaven.
A group of people in the same dormitory got up and continued working the next day after a long sleep.
Small but complete.
Although the six people are building small drones, the process from design to manufacturing to test flight is exactly the same as that of a large aircraft.
After submitting the creative ideas and performance parameters of the work, Zhou Yan and a group of brothers in the dormitory went back to review the entire process.
Just like aircraft design, we went over it again according to the complete process of aircraft from design to test flight that Zhou Yan is familiar with.
Throughout the entire process, Zhou Yan sorted out the principles and information involved one by one.
A group of brothers in the same dormitory also knew that the opportunity to study was rare. Whenever get out of class was over in the afternoon, they would run back to the dormitory with their notebooks in hand. When Zhou Yan came back and closed the door, they would start eating Xiaozao.
At the beginning, the students in the same class didn't know about the process of eating small stoves. After the instructor accidentally learned about it, "small stoves" turned into "big pot meals".
Of course, the instructor couldn't ask Zhou Yan to retell the whole process. He just asked him to use his evening self-study or after-school time to explain the professional foundation and principles of design to his classmates...