Chapter Twenty-Eight: Printing New Coins and Developing Flying Machines

"Hey, hey! There's no more chit-chat. Hearing Zhang Zhimu's question, Lu Chengxiang smiled and said, "Mr. Zhang! We also need to print kiln coins. Hui merchants and Zhejiang merchants both sent telegrams, saying that they would immediately come to participate in the land auction to participate in the bidding, but also said that their ticket numbers would also be expanded, and they needed kiln coins. Are we ready first? ”

"Aren't there still a lot of prints at home last time?" Zhang Zhimu asked.

"Hey, it's been a long time coming. You don't know, the local branches also need to be turned over by kiln gangs. Now in the underground warehouse of our kiln, there is a lot of gold and silver. Lu Chengxiang said.

"Then print it, I see that the kiln coins we issue are far worse than the risks we take." Zhang Zhimu said.

"It's okay, our kiln coin is the most popular. In Shanxi and Shaanxi, few people are willing to go anywhere with silver. Let's print it! Lu Chengxiang said.

"Hey! Wait a minute. Zhang Zhimu remembered that there were counterfeit banknotes printed in Beijing, "Mr. Lu, I think we should print a new version of the kiln gang coin." Now we have our own paper mill, which can specialize in the production of one or several types of paper with watermark patterns, or even double layer paper. Then it is printed with new inks. Also, we can issue new coins, which are made of special alloy aluminum, which are stamped with a stamping machine. The anti-counterfeiting performance of these things is very good, and it is easy for people to identify them in the market. ”

"That's right! It would be nice if that were the case. We're making a lot better paper now. Those rounded corners made of aluminum will be lighter. I also suggested that we should leave holes in the coins to satisfy people's habit of wearing money with hemp rope. Lu Chengxiang very much agreed with Zhang Zhimu's opinion and also put forward suggestions.

"Of course, you have to take care of that. I think it is necessary to ask the editor-in-chief Fan and their plate-making technicians to be responsible for designing various denomination kiln coin patterns and plates. After we have designed the watermark pattern, we also have to ask the paper mill to make this special paper according to the quantity we specify. I see that the inside of the paper should not only have a watermark, but also a silk thread between the two layers of paper. Outsiders don't have special paper, and they can't imitate it. Zhang Zhimu said.

"Yes, when we make paper, we have to send people to supervise on site, and we must make the special paper we need according to the specified quantity. The secrets of papermaking should also limit the number of people who know. Scrapped paper must be destroyed in person in the presence of several people. In this way, we can ensure that others can't get the special paper that we use to print kiln coins. Lu Chengxiang was more thoughtful.

"That kind of alloy aluminum, we also have to make it according to a special alloy formula, and then press it with a special mold. That way it's angular and it works really well. Actually, it is estimated that no one will think of copying the coin. Because the price of the aluminum alloy itself is likely to exceed its face value. Zhang Zhimu said.

"You arrange a time, and we'll look into printing new money." Lu Chengxiang said.

"Wait until I'm done with the lecture." Zhang Zhimu said, "I'm going to give a lecture to Li Yunhe and his people tomorrow. ”

"Good! I'm waiting for your arrangement. Mr. Lu said.

"Hey! Speaking of land auctions, I don't think we have to make a lot of money. Mr. Lu! Zhang Zhimu said.

"Hey! Why is that? Mr. Lu, who was holding back enough and wanted to make a lot of money, was a little anxious.

"That's the case, we should focus on attracting investment, as long as we invite everyone here, it will bring prosperity to the kiln. We just need to figure out how to collect the taxes. The price of land is too high, which is not conducive to the future development of Yaogang. In the future, the price of housing will grow beyond everyone's affordability. Zhang Zhimu said.

"Oh! That's what you're talking about. Lu Chengxiang said, "In the future, our large-scale production enterprises will be built in Taiyuan." As much as possible, there are traders, schools, and theaters built in Yaogang. We can expand the housing land to the north, all the way to Xishan Baozi. How many people can live there. "Lu Chengxiang will not give up the silver that he can earn right away.

Zhang Zhimu also felt that it seemed that he had been concerned about this matter a little earlier, so he didn't insist. He smiled and said, "Hehe! Okay! I don't care about these things, you can do it. ”

"Yes, yes, I'll take care of the money. If you take care of it, you will lose a lot of money as soon as you raise your hand. Your hands are too big to manage your money. Lu Chengxiang and Zhang Zhimu talked much more casually than before.

Because he chatted with Lu Chengxiang a lot, Zhang Zhimu went home a little late in the evening.

As soon as he entered the house, Zhang Zhimu heard Huang Yukun reprimanding Xiaohu. Because Xiaohu came back late.

"Uncle didn't tell you that there have been too many people lately. Do you want to come back from school with your escorted uncle? It's good that you're gone. Make those uncles anxious to cry. You don't know how many people were sent out to find you? You're fine, you're back like a good person. "Huang Yukun is getting angrier and angrier the more he talks.

Zhang Zhimu understood what was going on. Worried about Xiaoqing Xiaohu's safety, they were escorted to and from school. This made Xiaoqing and Xiaohu very unhappy, now is the most lively time in the kiln, and the streets are full of people. But they are not free. After Zhang Zhimu told them about it, they also knew the seriousness of the matter. But Xiaohu probably can't stand it today. I secretly ran out to play.

Seeing Zhang Zhimu coming back, Xiaohu had a fighting momentum, "Mom! I didn't run around, my classmates and I went to the proving ground together, and we watched the power car show. ”

"You're still talking back....."

Huang Yukun was even more angry, but Zhang Zhimu waved his hand to stop her.

"Xiaohu, you can go to see the power car, but have you thought about it? How anxious will you be that the uncles who picked you up can't find you? Zhang Zhimu said to Xiaohu.

"I let them know, and they won't let me go. My classmates all went, and I wanted to see the power car. The uncles who ride the power bike put on a good show. There are so many people watching. We barely made it in. Xiaohu said.

"Don't act without permission in the future, your mother knows that you are gone, do you know what will happen in a hurry? You don't know how many people have gone out to look for you. Zhang Zhimu said patiently.

"I was wrong, not anymore." Xiaohu finally admitted his mistake.

"Good! It's good to know it's wrong. Zhang Zhimu said, "Later, I want to get you and Xiaoqing a power car." Wouldn't it be better for you to ride and play on your own? Zhang Zhimu said.

"Really?" Xiaohu was happy, "But that kind of power car is too big." ”

"Don't you have small bikes, too?" Zhang Zhimu said.

At this time, Xiaoqing came over and asked, "Uncle, do you mean that the power car can also be made into a small one for us?" ”

"That's right! It is a small power bike that is suitable for riding in the city. Zhang Zhimu thought of the kind of small scooter in his previous life. At present, the road surface in Yaogang City is basically hardened and very flat, which is suitable for small pedal driving.

"This bike isn't fresh yet, what are you going to get a power bike? Now the streets are full of bicycles, and people have to look around when they walk. No matter what kind of power car there is, let people not go on the street. My cousin came over and muttered.

Now Yaogang is indeed full of bicycles on the street. Although the bike is still not a cheap thing. However, the postmen and others on the streets work by bicycles. Those who go to the kiln gang have to buy a bicycle at home, which is a status symbol. Especially Yang Yulin and Xiao Hongyu rode around when they had nothing to do. Those fashionable men and women are following the trend. In particular, Yaogang's bicycle has been improved for several generations, and it is already getting more and more beautiful. There are also more and more varieties. Many small traders want to buy a heavy-duty bicycle. Such a car can ride away with one or two hundred pounds of things. In particular, the road conditions in Shanxi are getting better and better, which is also accelerating the popularity of bicycles.

Yang Yulin hugged her daughter and asked, "Brother! Bicycles are available for women. Shouldn't there be a women's version of the power car? ”

"Of course, the city power car is unisex." Zhang Zhimu knew that Yang Yulin was interested in new things, and now he was interested in power cars.

Huang Yukun hurriedly said, "Yulin, you can't ride any power car." Be mindful of who you are. ”

Yang Yulin stuck out her tongue and said, "Oops! Sister-in-law, just pay attention to your identity. I don't have to be too tired. ”

Xiaoqing said beside him: "The power car will be the most attractive thing in the kiln in the future." ”

"Hey! Xiaoqing, you're not small. In the past, you are so old, it is time for you to live with your family. Now let your uncle still be used to it like a child who has not grown up. The cousin spoke again.

Zhang Zhimu hurriedly relieved Xiaoqing and said: "Xiaoqing wants to finish college and then get married." ”

"How old was that time, and who else wanted?" The cousin said to Huang Yukun again, "You are also a mother, the child doesn't want to do this, and you don't want to." ”

"I'll stay at home and not get married." Xiaoqing said, "No matter what you say, I want to finish college." ”

"That's right! I support Xiaoqing. Zhang Zhimu said, "We Xiaoqing don't have to worry about getting married." When Xiaoqing graduates, the person who proposes the marriage can not open the door. ”

Speaking of Zhang Zhimu, he was also thinking that it had been almost five years since he came to this era, and Xiaoqing was already thirteen. When I first arrived, Xiaoqing was still an eight-year-old girl with a yellow face and thin muscles. Now she is tall and tall, and she knows that she is very healthy and looks like her mother, very beautiful. The little tiger has also grown taller. In the past five years, great changes have taken place in Yaogang, which has also affected the original historical trend of the entire world. It seems that history can be changed.

Zhang Zhimu didn't expect that there would be so many people attending the lecture this time. In addition to those who are engaged in gasoline engines, there are also the entire people who are engaged in automobiles. Not only did they come, but so did the two dozen drivers who were engaged in the test run of the power car.

Li Yunhe said to Zhang Zhimu: "There is no way, they all heard that we are going to build a plane, so they have to come over." They said that no matter what you do, you need someone to try it. I think that's right, just let them hear it. Anyway, these riders have a good level of education. ”

"They're right, I think our first batch of pilots is really going to be selected from among them." Zhang Zhimu said.

In this course, Zhang Zhimu first explained Bernoulli's theorem again, introducing the principle of high velocity and low pressure in fluids. Although I have told you this in physics class before, many people have not heard of it. If you haven't heard it, you're not impressed. This time, Zhang Zhimu deliberately made two small planks according to the cross-sectional shape of the wings of the aircraft, and placed two shafts. When the concave surfaces are opposite, they are used as a blow to separate the two wings. Through this experiment, it has been proved that such two wings can produce vitality when moving into the wind. And further guide everyone, if this wing model is big enough and the wind speed is fast enough, then it will produce a lot of vitality and can lift very heavy objects.

With this conclusion, Zhang Zhimu took out another drawn model of the aircraft. On this diagram, the two planks that were used for the experiment have been turned into two wings. For this aircraft, Zhang Zhimu painted a lower single wing, a rear three-point landing gear, a single vertical tail, and a horizontal wing.

Combined with this diagram, Zhang Zhimu introduced how the aircraft relies on flaps to raise the aircraft's windward angle, how to rely on the rear wing feedback to maintain the stability of the aircraft, and how to rely on the tail steering. And how to rely on propellers to power the aircraft.

Several basic concepts are also introduced:

1. Lift-to-drag ratio:

It is also called "lift-to-drag ratio" and "aerodynamic efficiency". The ratio of lift to drag at the same angle of attack in flight of an aircraft. Its value varies with the angle of attack, and the higher the value, the better.

2. Aspect ratio:

The square of the wingspan (the length of the wing) divided by the wing area, for example, a circular wing is the square of the diameter divided by the circle area, which is used to express the relative degree of extension of the wing.

The small aspect ratio wing leads to large induced drag, which in turn makes the lift-to-drag ratio small, and the range performance is not good, but the maneuverability is good.

3. Glide ratio:

For every 1 meter of the aircraft, the gliding distance is called the glide ratio. The best gliders have a lift-to-drag ratio of more than 100 and a glide ratio of more than 40. The factors that determine the size of the glide ratio depend on the following points.

1. Large aspect ratio The wing with large aspect ratio has low induced resistance, high wing efficiency, and large gliding ratio. Others add winglets to further eliminate induced drag.

2. Streamlined In addition to induced resistance, another power loss is differential pressure resistance. The advancing object has high pressure in front to form a block, and low pressure in the back, forming a drag. If a flat plate circle is based on a resistance of 1, then the cylindrical resistance is 0.6, the spherical is 0.3, the egg shape can be reduced to 0.1, the drop shape can be reduced to 0.04, and the elongated drop shape can even be below 0.01.

The fuselage of advanced gliders is generally elongated in the shape of a drop, and the wings are in the shape of a half-elongated droplet, so the drag is minimal.

3. Reduce weight. Weight, like drag, is a primary concern in aircraft design. The increase in weight directly leads to the increase of the sinking rate, and indirectly causes the glide ratio to decrease greatly. The way is to use materials with large strength ratios, such as alloys of metals such as aluminum, magnesium, titanium, carbon fiber, fiberglass, etc.

4. Wing lift calculation formula

Lift L=1/2 * Air density * square of velocity * Wing area * Wing lift coefficient (N)

As can be seen from the wing lift coefficient curve, the slope of the curve is constant at small angles of attack.

Let me tell you that when we design an aircraft, we need to measure the jitter point, automatic elevation point, reverse lateral maneuvering and direction divergence point and stall point of this curve.

Zhang Zhimu knows very well that it is impossible for people who do not fully believe that machines can fly to fully understand these concepts at once. However, these basic concepts must be introduced to them first, and they will naturally understand them when they apply them later.

Zhang Zhimu knew that with such a little knowledge, he wanted them to build airplanes, which was a joke. However, in his previous life, when Zhang Zhimu finished diving and studied for the diving certificate together, several people in the same study class were ready to go paragliding together. Maybe if you don't cross over, you may have got a certificate now. At that time, everyone passed on some of the materials they got to each other, and Zhang Zhimu also made a set of copies. Several people also wanted to find the materials themselves to try first. Although I didn't have a chance to get it, the structure is still very clear. It's just that I can't remember the specific size, so I can only remember an approximation. Zhang Zhimu wants everyone to start with the delta wing. Try to make a non-powered delta wing first, find a feeling, and add power. As long as you can fly, everyone has confidence. Let's do airplanes again, maybe it's soon.

However, when Zhang Zhimu hung up a triangle wing figure he had drawn and told everyone that he wanted to fly with this thing, the result was full of laughter. Everyone thought Zhang Zhimu was joking.

Zhang Zhimu stopped everyone's laughter solemnly, and said: "Everyone laughed, I can understand it, because you don't understand the greatness of this simple thing. I tell you, the dream of human beings to soar into the blue sky is to start from it! ”

Hearing Zhang Zhimu say this so seriously, everyone fell silent.

Seeing that everyone was completely quiet, Zhang Zhimu said: "In the future, when you encounter problems that you don't understand, don't jump to conclusions first, so that there will be no more stupid laughter like today." ”

Zhang Zhimu's words were very serious, and everyone realized the seriousness of the problem. Fortunately, Zhang Zhimu did not dwell on this matter anymore, he said: "What you see is a kite-like thing formed by covering a skeleton with a silk cloth. Actually, if you look at it well, you will see that the upper part of the wing is raised and the lower part is empty. If the wing moves forward, the air flow from the convex surface above will flow faster than from below, so that the pressure above will be less than that below, creating an upward pressure differential. If the wing moves fast enough, then this pressure difference can bring people up. Is it possible for a man to fly on this wing? ”

Someone below started nodding and saying, "Yes!" ”

Zhang Zhimu struck while the iron was hot and said: "Let's first build a non-powered delta wing and try to fly, and then build a powered delta wing." You may ask, how does an unpowered delta wing move forward? Let me tell you that our air forms updrafts on the slopes of the mountains. We can use delta wings to lift into the air on updraft. Usually we feel that the wind is blowing in our faces, but in fact, there are still a lot of air currents in the air to move up and down. We use delta wings to find updrafts and fly very high. We have quite a few good powercars here, and I would suggest that you have the guts to fly into the sky and show off your skills. ”

Zhang Zhimu's words made those test drivers eager to try one by one. One couldn't help but ask: "Mr. Zhang, when will your delta wing be made!" Our brothers can't wait! ”

Hearing this, the audience burst into laughter. Zhang Zhimu said: "Today I brought the approximate size. After we got out of class, we asked Li Yunhe to arrange for someone to make this delta wing. However, don't be afraid to try and pee your pants when the time comes. ”

Zhang Zhimu's words drew laughter again. The man hurriedly said, "No! No! ”

Zhang Zhimu also introduced: "The best material for making this delta wing is still molybdenum tube. Because molybdenum tubes are light in weight and have high strength. With such materials, Li Yunhe wants to ask Liu Baoxue to prepare them. In our delta wing, the length of the side beam is five and a half meters, the middle beam is four meters five, the distance from the wing tip to the beam is two meters five, the beam is three meters, and the angle between the middle beam and the side beam is 60 degrees. The main beam is one meter two, and the tripod is one meter five x thirty. The width of the center wing is 3.5 meters, and the width of the tail wing is 1.3 meters. ”

After Zhang Zhimu introduced it like this, everyone believed that this thing would definitely fly. For a while, there was a lot of discussion. After everyone was quiet for a while, Zhang Zhimu said again: "You see, if we fix a small car on this tripod, install a gasoline engine-driven propeller on the car, and blow the wind backwards to generate a forward power, what will happen?" ”

It was quiet again. Zhang Zhimu continued: "Our delta wing will move forward on its own and then fly!" ”

Someone asked: "Mr. Zhang, how high can this thing fly?" ”

Someone else asked, "How far can this thing fly?" ”

Zhang Zhimu smiled and said, "Hehe! These are your questions that need to be answered by our pilots here. I don't know! ”

There was another burst of laughter from the people listening to the lecture below. However, this laughter, Zhang Zhimu heard some confidence.

It took Zhang Zhimu two days to teach these courses.

After the lecture, Zhang Zhimu left these people who were engaged in power cars. Say to them, "Your power car is now scheduled for production." Still, those are suitable for off-road use and are a bit bulky. I want you to develop a pedal type power car with a small displacement that can be driven on hardened roads in the city. This kind of power car should have a simple structure, cancel the clutch, and use the belt to drive. Minimise noise and exhaust emissions. This is civilian, and in the future it will be more popular with women, the elderly, and children than bicycles. ”

After speaking, Zhang Zhimu drew the basic shape of the pedal power car with a pen. The team leader who developed the power car said, "This is no problem. We'll look into this stuff right away. However, it will delay the development of the aircraft. ”

Zhang Zhimu said: "Now, for the time being, you don't need to be too distracted by the delta wing. Let's develop a pedal power car first! ”

Li Yunhe came over and said: "Mr. Zhang, they have the basis for developing off-road power vehicles, and it should be no problem to develop civilian power vehicles." After speaking, he said to the team leader, "When you develop civilian products, you must consider the appearance and comfort." You can take a look at the new bikes we produce. Their bikes are getting better and better. ”

When Zhang Zhimu was sent out, Li Yunhe's words made Zhang Zhimu look at him differently.

-------------

Mt. Fuji erupted, Japan was earthquaked. --Progress of "Memories of the Southern Song Dynasty".