Chapter 470 Back to the old problem
Sitting on a chair, two comrades next to me were talking quietly.
"You said this thing won't fall, right?"
"Guanggungun, can't you say something nice?"
"Comrade, you can't be feudal and superstitious. Ah.”
"If you don't have feudal superstition, you can't bring yourself to be unhappy, right? It's true."
After hearing this, Gao Zhendong said with a smile: "It's hard to say anything else, but this plane is really not afraid of falling. . ”
If the plane falls, as long as it does not disintegrate or directly hit, there are several possibilities.
Either it has no power to glide to the ground, or it stalls, or it enters a tail spin.
However, this flying tractor is not afraid of these situations at all.
This thing has extremely strong gliding ability and excellent low-speed performance. The speed required for gliding is very low. Even if there is no power, it can still glide slowly and find a place to land without any trouble.
It is also difficult to make it stall. How good is its low-speed performance? Among its parameters, there is no minimum take-off speed. Unreliable news is that it is 45km/h, which is what excellent cyclists pedal. It can take off at any speed it comes out, and it is not impossible to take off on a windy day.
The takeoff and landing distance of this aircraft is less than 200 meters, and it is also a serious transport aircraft, which is quite amazing.
There was a famous scene. The plane flew in the air for a long time. When it looked at the landmark, it didn't move. The flight speed and the oncoming wind speed offset... offset...
As for What to do if it really stalls or enters a spin for some other reason? Well, the tutorial on how to get this airplane out of a spin is roughly like this.
"Let go! Put your feet back!"
That is to say, as long as the altitude is slightly higher, let go of the joystick and don't pedal the rudder. This aircraft will correct its spin on its own, which is amazing.
This is why it has been used for decades. It has a simple structure, low cost, good safety, low operating cost, and good load capacity. It is very popular.
Don't worry about whether it's noisy or not, just say whether you can get there or not.
Gao Zhendong probably explained the benefits of this aircraft to the two comrades accompanying him. The two comrades were stunned for a while. Chief Engineer Gao knew everything.
This reminded Gao Zhendong of the feeling of giving equipment to his deskmate in high school. The deskmate just stared at him with a pair of big flashing eyes and pointed out the country, saying "I don't want to understand at all, but I really like to listen to you." look.
It’s a pity that the two old men in front of me have passed away and can’t come back.
The tractor flew in the air for several hours. Gao Zhendong and the comrades in the internal security were fine, but the comrade who worked on the machinery couldn't help vomiting, and in the future, civil aircraft could fly to the stratosphere above 10,000 meters. Different from tier cruising, the practical ceiling of the flying tractor is only 4,500 meters, which is exactly within the range of relatively violent atmospheric activities.
It was already shaking, but when it was blown by the wind, the feeling was so sour and refreshing.
I don’t know if this comrade who works on machinery will come out and brag about the things he vomited like this after he returns home, Gao Zhendong thought rather unkindly.
A few hours later, the plane finally landed safely at the airport on the outskirts of Changji City. To be honest, Gao Zhendong was really not worried about safety. This thing was uncomfortable, but the safety was still high. He was just worried about riding it again. Comrade, that body can't bear it.
To Gao Zhendong’s surprise, the people who came to pick him up were not comrades from the Northeast Optics Institute, but several comrades from the local army.
The leader saluted Gao Zhendong: "Hello, Chief Engineer Gao, I am from the local army, my surname is Zhao, and I have been ordered to cooperate with your activities here." After speaking, he handed over his ID. He came over and was picked up by a comrade from the internal security of the No. 3 Factory.
Gao Zhendong didn’t know where the order came from. This time he came here, it had little to do with the work of the army, or it had little to do with it directly.
But he still expressed his gratitude first, and the comrade in internal security also handed back the certificate and nodded to Gao Zhendong.
Following the arrival, he got into a jeep parked outside the airport and went straight to the Northeast Optics Institute as requested by Gao Zhendong.
When they arrived at the Institute of Optics, it was already past three o'clock in the afternoon. Comrade Gao Zhendong, who was in charge of the optical system at the Institute of Optics, received them. The comrade's surname was Li, the same surname as Li, the deputy director of the No. 3 Rolling Plant.
Gao Zhendong’s idea is to cut through the mess quickly, finish all the matters as soon as possible, and return to the capital, where there are still many things going on.
However, as usual, the comrades from the Institute of Optics still took a few of them to visit the Institute of Optics. Of course, they were limited to the parts that could be visited.
Finally, Li Gong took Gao Zhendong outside a laboratory, pointed at the laboratory and said: "General Manager Gao, here is the laser beam expansion optical system you want. It is now on standby. status.”
Gao Zhendong perked up, and under the leadership of Li Gong, he put on protective clothing and entered the laboratory.
The protective clothing is not to protect Gao Zhendong and the others, but to protect the equipment and ensure that no large amounts of dust, etc. enter the laboratory.
What caught Gao Zhendong’s eyes was a slightly cylindrical metal object. Most of the optical system was wrapped inside. There was a hole in the middle of the side. This hole was used to place the mask. of.
Gao Zhendong and the comrades in charge of machinery looked at the machine carefully. Comrades from the Institute of Optics introduced to them: "This machine has a working wavelength of 355nm. The optical modulation transfer function is about 0.63 at the ideal position, and the optical path difference is less than Quarter wavelength, numerical aperture 0.029, magnification 1. "Gao Zhendong really didn't understand. Except for the working wavelength of 355nm and magnification 1, he didn't know anything else: "Gong Li, this means. What are you wearing? ”
Li Gong didn't take it seriously. After all, this person was not an optics person: "This means that his resolution is 9μm."
9μm? Gao Zhendong was immediately blown away. With this resolution and small deformation, a 10μm line width is not a dream.
"Gong Li, how about the deformation of the image?"
"It is very small, the maximum field curvature is within 15μm, the maximum astigmatism is around 7μm, the overall distortion is less than 1ppm, the image plane The non-uniformity is less than 2%, I think there is no problem with your requirements," Li Gong said with a smile, and he was quite proud of it.
For this machine, the projection diameter required by Gao Zhendong is about 160mm, and the distortion of 1ppm means less than 1μm, which is completely sufficient for Gao Zhendong’s idea.
Gao Zhendong laughed loudly: "Li Gong, thank you so much! Thank you so much for your hard work!"
Li Gong smiled and said: "It will be good if I can meet your requirements. It is relatively late today. Other specific matters , How about we continue tomorrow?”
Gao Zhendong nodded in excitement: “Okay, I won’t bother you comrades today, we will continue tomorrow.”
That night, Gao Zhendong. I tossed and turned and thought about it for half the night.
Early the next morning, Gao Zhendong and his people arrived at the entrance of the laboratory early. Engineer Li was already waiting there. The group changed clothes and went in.
After Gao Zhendong entered, Li Gong began to arrange for people to use standard masks to conduct a complete test. After all, he said yesterday that the complete test process would be walked through for Gao Zhendong and the others. This was considered Party A's responsibility. Come for acceptance.
While the experiment was going on, Gao Zhendong was looking at the indicators of the entire optical system. He wanted to see if he could achieve his idea.
Looking at it, he frowned.
"Gong Li, the light transmittance of this system is more than 30%?" Gao Zhendong asked.
It was not good for him to say "only more than 30%".
A slightly embarrassed look appeared on Li Gong's face: "Well, the wavelength of 355nm has already entered the ultraviolet wavelength. The light transmittance is inherently poor, and due to the material, it is more ugly."
Ultraviolet wavelength is 10nm to 400nm. It has high energy but poor penetrability. This is a bit like alpha rays in radiation. It has the highest energy, but common alpha rays can be blocked by a piece of printing paper.
This light transmittance is because the wavelength of 355nm is relatively long and the penetrability has not deteriorated to the end.
This makes Gao Zhendong feel a little difficult. In this way, if the second step requires micro-projection and the micro-optical system is added, the light transmittance will further deteriorate, although that step is to focus. Yes, but even now, the light transmittance has reached the edge of danger. Increasing the laser power is not as simple as working hard to achieve miracles. The higher the light transmittance can be retained, the better.
It’s hard for Gao Zhendong to say now. After all, it’s barely enough. He just asked: “What is the light transmittance of the current materials?”
"The light transmittance of 10mm at 400nm wavelength is not less than 99%, and the light transmittance of 10mm at 300nm wavelength is not less than 30%. This is already the effect after adding anti-reflection coating."
Oh, this can be reduced enough It’s fast. No wonder the data is so ugly. 355nm is definitely much better than 300nm, but it cannot support an optical system with multiple lenses.
Gao Zhendong nodded and expressed his thoughts while watching the test.
"Gong Li, can the resolution of this system be 5μm or even better in the second step?"
He wanted to give it a try.
After listening to his words, Li Gong shook his head.
"It's difficult. This is already our limit. If nothing else, the processing cost will be extremely high. If it increases to the level you mentioned, our current manual processing method will be the best. It is no longer practical, and the processing cost will be extremely high, making mass production impossible."
Gao Zhendong was not deterred: "If the cost is not considered, what about one or a few sets?"
< br>Li Gong's eyes lit up, and then dimmed: "The processing is possible, but if we improve it further, our materials will not be able to hold up, and there is still no point."
"Material? What material?" Gao Zhendong broke the casserole and asked the truth.
"Optical glass, we are currently using Crown Optical Glass, its parameters such as light transmittance, thermal expansion coefficient, etc. are not very good, either affecting the key indicators of the optical modulation transfer function, or affecting its environmental adaptability, small temperature fluctuations will It may cause performance degradation. As for this, there are strict operating temperature range requirements.”
Back to the old problem, materials.
Crown optical glass is not a brand, but a type of optical glass.
(End of this chapter)