Chapter 40: Blue Sky Dream, Where Does It Come From And Where Does It Go

  "When we were young, we often saw small birds flying freely in the sky, flapping their wings and soaring into the distance. The blue sky was dotted with white clouds, and in this beautiful natural setting, they could enjoy themselves to their heart's content. Flying towards the blue sky became our earliest childhood dream!"

  "If we could really grow a pair of wings and fly into the blue sky, that would be monstrous! Let's see if we humans can find a way to harness mechanical power to conquer the skies!" Zhang Yu looked at Wang Zhuo, who had two black eye circles, and could only help him pick up the scattered drawings.

  It's been said that the second row of students who returned to China are very hardworking. Today, Zhang Yu specially made time to come and take a look. As a result, he found that his own room was in an even more chaotic state. This clearly told Zhang Yu that these people were indeed workaholics who forgot to sleep and eat. "Wang Gong, this baozi congee is soft and needs to be eaten slowly." Looking at Wang Zhuo wolfing down his breakfast, Zhang Yu vaguely felt the same kind of exhaustion he had when he was working on the Beetle project.

  "I've always treasured them, never used them as a tablecloth!" After finishing the last meat bun and drinking a few mouthfuls of porridge, Wang Zhu wiped his mouth with both hands. One breakfast was settled. "I accidentally slept for eight hours last night, which is enough. By the way, since you came uninvited, I have many questions to ask you here. Why don't we sit down and study them together?"

  "Research is fine, but this office doesn't seem to have a place for me to sit!" Zhang Yu looked around and saw two chairs, both piled high with books and magazines. The only stool had a bowl on it that was so dirty it was impossible to tell what day it had been used to hold leftovers."

  "We'll sit on the floor, and the drawing can be fully unfolded!" After that, Wang Zhuo immediately asked Zhang Yu to help move those chairs and stools aside, clearing out a large space for the two to sit on the floor. Of course, there was more than one square meter of space between them, just enough to unfold the drawings.

  "According to the information you provided, after analysis, we also decided to abandon the research on biplane aircraft. As the data described, the reason why an airplane can fly into the sky is mainly due to its flight speed and wing area. The greater the flight speed and wing area, the greater the lift generated, and the larger the single-machine payload or the faster the speed. We have the conditions to develop better engines to give aircraft more power..."

  As Wang Zhuo said, early aircraft, due to the lack of good engines and rough and simple structural materials, could only increase the area of the wings as much as possible to obtain sufficient lift. One wing was not enough, so two or even more were used. However, biplanes and multi-winged planes had slow speeds and poor maneuverability. With the progress of aviation engine technology, they would inevitably be eliminated one by one, because better engines made it possible for single-wing aircraft to have sufficient lift as well. Of course, the best and most advanced aircraft in the world at present are still biplanes used on the battlefield during World War I.

  "Biplanes have their own reasons for existence and usage, with slow speeds and considerable payloads, they will never be outdated. For example, in the future we can use them as agricultural aircraft to spray pesticides, which is still suitable for slow-flying planes. So I can only say that our research focus is on monoplanes, but not categorically excluding biplanes. By the way, have you finished reading all the materials I gave you?" Zhang Yu still liked sitting on the floor while working, with large sheets of paper spread out directly on the ground, making it very convenient for both parties to view the full sheet of paper during discussions.

  "Just as you said, we put all our research on the all-metal monoplane. With advanced engine technology, we studied the three sets of drawings you provided. The single-engine high-speed aircraft, the twin-engine transport plane, and the four-engine large transport plane, we researched each one." As he spoke, Wang spread out a main view drawing of an airplane and began discussing it with Zhang Yu.

  Aerospace engineering is actually very similar to automotive engineering, it requires professional aircraft design, material selection, component manufacturing, aircraft assembly and shaping, etc. The entire process is almost a replica of the automotive industry, one is running on land, the other is flying in the sky, the two industrial systems are similar but also have differences. In terms of specific manufacturing, the two are almost the same, but the difference lies in the materials used for manufacturing and product design. Of course, aircraft design requires more consideration and is more complex, but it is restricted by natural conditions, and the change in aircraft models is not great. On the other hand, the materials used in aviation have been advancing continuously and at a faster pace than the automotive industry.

  The materials used in human spaceflight have gone through several stages of progress, including wood, steel, aluminum alloy, titanium alloy, plastic, composite materials, and special alloys. In the first stage of material use, spruce and ash were used most frequently. The Wright brothers' first aircraft with a piston engine used wood for nearly 50% of its structural weight, including World War I biplane fighters and large bombers, which were also made from engines, wood, steel wire, and other materials.

  Wood, due to its certain strength and toughness, especially its light weight, made it quite successful in the application of slow-speed biplanes. However, with the increase in aircraft speed, load, structural complexity, usage cycle, and environmental changes, many unpredictable factors would pose great challenges to the fragile wooden structure. Sooner or later, more durable and reliable metals would be used in aircraft materials, but the autonomous region just wanted to enter the second phase a little earlier, so as to occupy the commanding heights of the aviation field.

  "Will future aircraft consume large amounts of aluminum alloys? Aluminum is widely used in metals today, but it's unclear whether it will meet the needs of the aviation industry in the future."

  The two men discussed the theoretical issues of aircraft structure design, and slowly transitioned to the second problem, which was the materials needed for aircraft manufacturing. Without suitable materials, it would be impossible to turn the painstaking research on paper into a usable physical object through processing and manufacturing, making even the best theoretical research and aircraft design futile.

  After looking at the drawings for a long time, Wang Zhuo, who originally had a talent for making airplanes, finally understood Zhang Yu's kindness and immediately raised a realistic question.

  When Wang Zhuo raised this question, Zhang Yu nodded in satisfaction. He knew that Wang Zhuo had already established the importance of metal aircraft in his heart. "This problem has been solved. In Pingguo County, not far from Nanning, we have established a large-scale aluminum smelting plant for metal aircraft. The duralumin alloy containing copper, magnesium, manganese, silicon, and iron elements has been applied to our cars. We have found that by adjusting the content of the added elements, we can effectively control the strength of the aluminum alloy. Different strengths of aluminum alloys can be mass-produced. Currently, on cars, especially sedans, we have used a lot of aluminum alloy materials, which have achieved very good results in terms of weight reduction and structural strengthening."

  In the manufacture of metal aircraft, the application of aluminum is exceptionally extensive. Aluminum alloys can be used in large quantities for aircraft frames, skins and load-bearing components. Although the strength of aluminum alloys decreases with increasing temperature, when the aircraft speed is higher, aerodynamic heating will affect the strength of aluminum alloys. However, within the flight range of 2.2-2.3 Ma, aluminum alloy materials can still be used to make aircraft structures. In other words, within a certain flight speed range, aluminum alloy aircraft are still king.

  Of course, Wang Zhuo, who did not grasp the overall development of the autonomous region, would definitely not know the current development status of the autonomous region and naturally would not know that China Aluminum Company has already had a relatively large production capacity. However, after getting Zhang Yu's satisfactory answer, he was relieved of his worries.

  "This is the best, the plane achieves takeoff and landing on land, its biggest difficulty is the structural strength of the plane, the plane's high-speed flight and agile maneuverability also depend on the power system and transmission control system. Let's put aside the two major researches for now and consider the structural strength of the plane..."

  "I know what you're thinking. Having a great engine and related systems is not enough if the body structure can't guarantee safety, just like a car. Aluminum alloy may be used for some parts such as aircraft frames, but it's not suitable for other places, such as the rear beam of the wing, main landing gear axle and seat, and wing root connectors. These places require materials that can withstand certain strength, don't forget what we're doing!"

  Zhang Yu's implication was that Wang Zhuo should think about the current autonomous region's industrial expertise, and even large-scale automotive system engineering can be taken down. If a product with good quality can be produced, it is naturally guaranteed by strong self-strength. It is worth noting that a car has 34 systems, including more than 130 independent assemblies, requiring more than 40 technical conditions, and the ability to manufacture 63 bearings, including standard bearings, which requires the ability to produce 29 standard standards. With nearly seven thousand parts in the whole body, how can we lightly enter the automotive manufacturing without being familiar with material preparation and application?

  "We have widely used Hadfield steel in the manufacture of automobiles and mechanical equipment. Hadfield steel contains 17-19% nickel, about 8% cobalt, about 3% copper, about 0.15% titanium, with a maximum carbon content of only 0.03%, plus limited amounts of manganese, silicon, sulfur, phosphorus, aluminum, boron, calcium and zirconium. Hadfield steel has higher fracture toughness and impact strength than ordinary low-carbon steel, and its heat treatment is simple."

  Here is the translation:

  After much effort, Zhang Yu managed to find some disposable paper cups and filled one for each of them. After drinking a cup of cold water from an unknown time, Zhang Yu continued: "Although the production cost is extremely high, its application in various hardware has indeed achieved very good results. Just like making cars, we can't sacrifice quality and performance to save costs on our planes either. If it's safe flying in the sky but causes accidents when landing, wouldn't that be a joke?"

  Zhang Yu threw the empty paper cup into the trash can and rummaged through the papers. "Right, I remember giving you a lot of engine materials, where did you put them?" After searching for half a day, they were all diagrams of various parts, or large drawings, but couldn't find any related to engines.

  "It's under my butt!" After saying that, Wang Zhuo awkwardly pulled out a large stack of drawings and said apologetically: "These things are too profound for me, it's simply too difficult, I've been able to survive these days with panda eyes all thanks to them causing trouble!"

  "Do you know the importance of these things far exceeds our automotive technical data? Use it to wipe your butt, you're really creative!" Zhang Yu took over the flattened drawings, unfolded them one by one and started reading. After a while, he said: "The Wright brothers' plane is like a toy, since you've been studying in the US for so long, how much do you know about their engine usage?"

  "Aircraft engine technology is the key to the entire aerospace industry, and it has been a major challenge for the global aircraft manufacturing industry. If there were good enough airplanes, I estimate that even the Wright brothers would not have worked so hard on their biplane designs. Of course, I've studied the four-cylinder inline water-cooled engine used by the Wright brothers, but this engine was not a professional aviation engine, its power-to-weight ratio was too small. In Europe, the Hispano-Suiza V-type liquid-cooled engine has already appeared, with a power output of around 130 horsepower and a power-to-weight ratio of around 0.7. I estimate that they can achieve a breakthrough in lightweight aircraft speed of over 150 km/h."

  "What's more? Continue to share your insights." If Zhang Yu hadn't read the data of Wang Zhuo from another time and space, he would have been quite skeptical of the carefree and unruly person in front of him who had no living rules. Due to their similar lifestyle and work habits, Zhang Yu could only half believe and half doubt whether he was an aviation genius as described in the history books of later generations, and needed to prove it with his abilities.

  "Moreover, air-cooled engines are extremely difficult to cool, and in order to cool them down, the engine has to be placed outside, greatly increasing the aircraft's air resistance. However, liquid-cooled engines can easily solve this problem, but there is also the issue of insufficient power. Therefore, I think that our aircraft manufacturing must first overcome the technical difficulties of the engine, otherwise we cannot even talk about metal structure aircraft. In my opinion, liquid-cooled engines are quite good and can be widely used to a certain extent. However, I know you will definitely have a better solution, please share it with me!"

  After circling around for half a day, Wang Zhuo finally brought up the key points he had been considering, which in his opinion should be the focus on engine development, and only then other aspects of research. Being circled around like this, Zhang Yu couldn't help but laugh, thinking that he was testing the other person, but it turned out that the other person was actually probing him, both people seemingly knowing that aviation should prioritize power research, yet both wanting to lead the other into thinking about other aspects, to see if the other person really had any ability. In the end, after circling around, the two of them coincidentally put their focus back in the same place and stopped circling.

  "I also know a bit about this liquid-cooled engine, I heard about it when I was in the US, the rotary cylinder air-cooled star-type engine invented by the French Seguin brothers. However, this thing indeed has limitations due to the fixed crankshaft and rotating cylinders, which cannot increase power output. A fixed-cylinder air-cooled star-type engine can definitely achieve better cooling effects."

  "To reduce engine drag, we can use an engine cowl, which also solves the cooling problem. If the engine is designed with two or four rows of cylinders, increasing power is not a problem either. The exhaust turbocharger will also increase the intake pressure under high-altitude conditions, improving the engine's high-altitude performance. If variable pitch propellers can be implemented, it will further increase the efficiency of the propeller and the power output of the engine."

  Zhang Yu quickly explained the various design functions by comparing them to the drawings. Of course, some chemical methods can also solve these problems, such as filling metal sodium into the exhaust valve to effectively solve the overheating problem of the exhaust valve; spraying a mixture of water and methanol into the cylinder can increase power by one-third in a short time; high-octane fuel will improve the anti-detonation performance of the fuel, increasing the combustion pressure inside the cylinder from 9, both improving the power and reducing the oil consumption rate.

  "We can actually start a project for the aviation industry now. Relying on a small research institute to study and not putting it into practice, how can we make substantial progress? Especially when the imperialist powers' planes are being used as weapons, we still hold a lot of advanced technical data and are thinking hard about better plans, why not boldly try it out?"

  "Just like that monster Premier said to you before: we originally had nothing, dare to innovate and work hard, even if we fail, we will still have gains, at most we can start again. Do you really believe in his nonsense?" Zhang Yu picked up the materials, stood up and looked at Wang Zhuo with two super dark eye circles. "Aerospace engineering seems to be just around airplanes, but it's much more difficult than automotive engineering. If you really want to climb, you need to have enough mental preparation."

  Zhang Yu sincerely told Wang Zhi the fact that he knew human beings, especially a region that wants to be a strong technological country, must advance from the piston era to the gas turbine era. Piston engines are not terrible and not a daunting task, but as the industry progresses, aviation gas turbines will replace piston engines, opening up an extremely difficult path for the jet age.

  In other words, for the aero-engineering industry dominated by piston engines, Zhang Yu is not worried that Wang Zhu and others do not have the ability to digest, but has established a foothold in the aviation industry, just like choosing a direction for oneself. Except for persisting without hesitation, there is no other way out. However, with the advent of the jet age, the huge thrust-to-weight ratio of turbojet and turboprop engines, the low fuel consumption and high takeoff thrust of turboprops, and the turboshaft engine used in helicopters, none of these are not tempting big items. Once you embark on this path, it will inevitably take up a lot of time, with at least five or six years, or even more than ten years, spent in hardship.

  Of course, Zhang Yu did not mention the future development issues to Wang Zhu and others, but dedicating himself to such a difficult industry was like jumping into a fire pit willingly. As someone who knew the situation, Zhang Yu had to let Wang Zhu consider carefully. "This aviation business is not like making cars, once it's launched, there will be a large amount of resources invested, and the autonomous region government will definitely have requirements for achievements. Cars, we can get results in just a few months, but planes are not that easy! Perfect theoretical research can make the road ahead easier to walk, so think about it carefully and give me an answer in a week!"

  "It's also true that there are many comrades in the institute, shouldn't we take on more responsibility? We still need to discuss it together, unity is the ladder of progress!" Wang Zhu said, and immediately started picking up the documents on the ground. The two were busy for a while before these treasures that should not be treated so carelessly were restored to their proper place, which was inside the iron cabinet. "Let's go ask others for their opinions. Blue Sky Dream, where are we headed..."