Chapter 56 Delightful Surprise

  Whether the engine is liquid-cooled or air-cooled, it doesn't matter. In today's world where the aviation industry has just started to boom, the engine is the biggest factor limiting its development. Whether a liquid-cooled engine can completely replace an air-cooled one, including Zhang Yu, no one knows, so both types of engines will continue to be deeply researched, and AVIC Engine has already reached the stage of engine testing.

  Surprisingly, the engine came after the airplane. The power used by the first human flight was not a professional aviation engine. The original gasoline internal combustion engine was first applied to drive an airplane and successfully made Lindenthal's glider, Wright brothers' "Flyer", and Feng Ru's performance machine all flew into the sky. Later, specialized aircraft engines gradually appeared, but their performance was very immature, including biplane fighters and bombers flying over the European continent.

  The engine is the indispensable heart of an airplane, and its importance cannot be doubted. The power of the engine has not been able to go up, and humans can only be limited to slow-speed aircraft with double wings, and they cannot feel the beauty of flying higher and farther. Therefore, human research and design of engines have never stopped.

  Early engines almost all chose air cooling as the cooling method, so they had to design effective cowls, conduct comprehensive aerodynamic research on the cowl and cylinder surroundings, and solve complex metal materials and other problems. The arrangement of the cylinder structure, the position and opening of the valve, the number of valves on each cylinder, and the distribution ratio of heat in the air space of the fuel, etc., it is clear that this is a systematic project, and the power of one person is absolutely limited, so it is impossible to achieve everything. Therefore, until now, there has not been a truly practical engine.

  The "V-8" engine used on the "June Bug" in 1908 was one of the more successful early air-cooled aviation engines. It can be said that it fully reflects the technology of pre-WWI aircraft engines, with a rough design, suitable processing techniques and material selection, this engine and its derivatives were almost used throughout WWI.

  Cast-iron cylinders, integral cylinder heads, had almost become the absolute commonality of engines of this period. Although the era was progressing, and people were working hard on the materials and casting technology used for casting, as well as the function of the finned cylinder jackets, the manufacturing technology of some core components such as the casting molds had not yet developed to the point where they could continuously cast cylinders that met quality standards. As a result, engines with short valve life and high oil consumption became the only choice, forcing pilots to hover between thermal disaster and mechanical disaster.

  In 1909, a three-cylinder air-cooled fan-type engine powered a monoplane that finally made the 37-minute flight across the English Channel. This unusual engine had cast iron cylinders with overhead valves operated by rocker arms and pushrods from a central camshaft, inlet valves were pressure-operated and held closed by light springs, opening under the influence of higher atmospheric pressure outside and lower cylinder pressure inside during the piston's intake stroke.

  Anyway, after people's efforts, the performance and safety of the engine finally have some guarantee. With enough power to produce cylinders, although still choosing alloy forgings and machining, not casting popular medium and low carbon steel and nickel alloys, the engine's performance is indeed good. Direct air-cooled radial engines can finally allow aircraft to fly freely for a certain period, of course, this progress has become a "big mistake", and humans who love killing will soon use airplanes to slaughter their own kind, and there are shadows of airplanes in wars.

  Among them, the most famous is the 50-horsepower "Guardian God" rotary engine produced in France. The unit power-to-weight ratio of the rotary engine is higher than that of other types of engines, which immediately attracted attention. To meet the needs of the military, Germany, France and Britain introduced this type of engine and further researched it, eventually producing a large number of their own rotary engines, finally allowing aircraft to enter the war and making the war more brutal.

  After being embroiled in a large-scale war, Europe, which had always led the tide of technological progress, seemed to have stopped its forward march. Especially for the three countries that were deeply mired in the quagmire - England, France and Germany - all their energy was almost entirely consumed by the war. Now they were only thinking about how to bring down their opponents as soon as possible, rather than spending a lot of thought on scientific research.

  On April 9, 1919, after the formal establishment of Zhonghang Power Company, the struggle between the liquid-cooled group and the air-cooled group under its research department entered a white-hot stage. Although the competition between the two had been verified by experiments at the beginning of the company's founding, the liquid-cooled engine had an absolute advantage in medium power, that is to say, for the liquid-cooled group, the engine used in future fighter jets must be liquid-cooled. However, the air-cooled group could only try every means to make the high-power and high-performance advantages of air-cooled radial engines manifest, that is to say, their goal must aim at larger horsepower air-cooled star-shaped engines, and they would not easily give up the field of fighter jets either.

  So, who is more capable and whose products are more practical in value still needs to be tested by real products. After all, the various factories of the newly established aviation group in other places have already started preparing for the production of key components of the first experimental fighter and transport aircraft. The air-cooled and liquid-cooled groups only need to produce their own engines and use actual test results to see who is more suitable. If it's still not working, then we can only use planes equipped with different engines and use actual flight results to see who is stronger.

  On June 24, 1919, the designs of the two groups were transformed into physical objects through the efforts of technical workers. The workers helped to push out two four-engine samples for the air-cooled group at once. The first was a double-row air-cooled star-shaped engine with a design power of 700 kilowatts, which was obviously intended for fighter aircraft applications and also indicated that they were not willing to give up this field and produced two for future experimental verification. The other was a four-row giant air-cooled engine, with twenty-eight cylinders in four rows, its power reached an astonishing 1800 kilowatts, and two were prepared for experimentation.

  The liquid-cooled group did not have the arrogance of the air-cooled group, they carefully crafted an engine, with a design power of only 700 kilowatts, and prepared two for future experiments. Although it was a bit lighter in weight, they were very confident, because they discovered a huge problem, the air-cooled engine had a significantly larger body size, which would be a huge disadvantage when applied to fighter jets.

  If both engines are to be equipped with suitable aircraft, it is clear that the group must develop different aircraft for each engine and experiment with them, which would indirectly increase the financial burden on the group. Of course, in the high-power engine project, the liquid-cooled team had indeed given up, as the liquid-cooled engine had no advantage whatsoever for transport-type aircraft that required range and payload, requiring a large amount of cooling water. Therefore, they concentrated their efforts on the medium-power segment, which was also an area where the liquid-cooled team would not give up, because they had no way to retreat.

  On June 26, in a certain test area of Liuzhou China Aviation Group, after some preparation, the six engines participating in the test began engine testing experiments. In the experiment lasting several days, technical personnel will test the main performance indicators of the three engines, including engine power, power-to-weight ratio, and fuel consumption rate, which are important indicators that determine the life and death of the engine.

  On July 3, the test results were released after repeated calculations and verification. The two engines of the air-cooled group performed relatively well, with a design power of only 700KW for both the air-cooled and liquid-cooled groups' medium-power engines. However, the experimental results of the air-cooled group reached a satisfactory 736KW, and its power-to-weight ratio was also very satisfactory, reaching 1.43 kilowatts per kilogram.

  The liquid-cooled unit, with a power-to-weight ratio of 1.22 kW, has a power output of only 728 kW, but its stability is extremely satisfactory. However, the air-cooled unit's dominance in high-power engines, specifically the 1800 kW monster, had very poor test results. It was forced to stop shortly after running due to engine overheating and dared not continue, but during its run time, it showed an astonishing 2000 kW of power. If not for the poor cooling treatment, this engine would likely have been directly mass-produced.

  "The higher the expectation, the greater the disappointment."

  This sentence perfectly describes the common fate of the two groups, who were full of confidence and prepared to show off, but one ended in a fiasco and the other was extremely disappointing. What they left behind was a detailed summary and slow improvement. However, they did come up with some technical parameters for the engine, which was sufficient for the overall design of the aircraft. The group agreed to design and produce two versions of the fighter jet, which would be tested separately in the future. Of course, the best outcome would be that neither version is superior to the other. It's undisputed that the air-cooled engine will not undergo significant changes in the future, and even if there are some dimensional changes, it won't require too many changes to the main structure of the aircraft. Therefore, the formal design of the large aircraft can also begin now.

  Long before the establishment of China Aviation Group, the aviation research project team had completed model testing of all-metal single-wing aircraft using wind tunnels. For the future aerodynamic layout of single-wing aircraft, a rough estimate of the geometric shape and some parameters have been made. Now that the initial engine size data can be determined, China Aviation Group immediately started the specific design work of the aircraft, striving to have a suitable model to match it when the engine is finalized. Of course, this strange aircraft design and manufacturing process is because China Aviation was really nothing at first, and everything in the future may be very different from now.

  The High-tech Development Zone of Liuzhou is located in the northeast of Liuzhou City, and the winding Liujiang River runs outside the park. After years of construction, the green trees along the river have been shaded, and the high-tech park is just across the wide avenue adjacent to the Liujiang River. Further inland, a wide cement road crosses the park, with a green isolation belt separating the two-way eight-lane road, allowing vehicles to drive in an orderly manner. Due to its important role and location, it has a loud name - High-tech Avenue.

  Independent "gardens" are distributed on both sides of the avenue, like square grids. There is a small green space around each "garden", separated from the avenue. Some gardens have already built high-rise buildings or factories, while others remain flat and empty, with grass covering the entire territory, making people passing by the High-tech Avenue think it's a future park.

  Of course, the largest scale in the high-tech zone is the Industrial University, but the second one is the autonomous region's industrial new star China Aviation Industry Group. People entering the high-tech zone can find the headquarters of AVIC, the tall and majestic blue and white building, which represents the dream of AVIC people pursuing blue sky and white clouds, and also a clear regional coordinate.

  Under the guidance of the prominent headquarters building, it is easy to find the location of China Aviation Group's headquarters park. From the fourth intersection of High-tech Avenue, there is a special entrance for the group, and another entrance may be used by an even larger group in the future. After waiting for the left-turn signal light to turn green, you can drive slowly to the entrance of China Aviation, and if you pass the security check and enter the park, you will soon arrive at a central roundabout.

  The main body of the turntable is a circular green area, but on a large granite stone wall lying in the small lawn, the golden font engraving indicates everything here, "China Aviation Industry Group". The building opposite the entrance is that magnificent ten-story headquarters building. After the establishment of AVIC, it became the office place for nearly a thousand people. Not far from the left and right sides of the building are two more majestic buildings. The 'stout' building on the left is responsible for various meetings, while the one on the right is an important unit, where the aircraft design department of AVIC is working hard.

  "For the sake of our blue sky dream, we can be said to have worked tirelessly! To think about it, it's even more exhausting than when we first planned to make cars."

  After finishing another day of voluntary assistance work, Zhang Yu and Zhang Yusheng were both exhausted, sitting in the car and leaning back comfortably on the chair, feeling like they were about to collapse. The progress of the engine was smooth, obviously with a deadline looming for the aircraft design project. To design a better plane, the two Zhangs came to help voluntarily, although they didn't make any huge contributions, but in some details, they both made reasonable suggestions, allowing the design team to avoid many detours.

  "After this experience, I really admire Wang Gong and his team. They are passionate and have a stronger work ethic than me...” Zhang Yu rubbed his temples, finally catching up on the rare rest day of the weekend, only to be dragged by Zhang Yu to do a day's worth of volunteer work here. The reason was simple - Zhang Yu's understanding of piston aircraft was not even as good as that of a 21st-century liberal arts student. "Tell me, at this rate, how long will it take for the plane to fly into the blue sky?"

  When hearing the praise of the design personnel, Zhang Yu, who was also rubbing his temples and doing eye exercises, could only nod in agreement. However, when it came to the question of when this plane would be able to fly into the blue sky, Zhang Yu immediately stopped his movements, furrowed his brow for a moment, and said: "I think it will take at most one or two years to prepare for the test flight. After all, what's so difficult about this propeller plane? The core components of the engine are fine, there shouldn't be any problems with the other parts."

  Regarding the development of propeller-driven aircraft, Zhang Yu did not exaggerate at all. Piston-powered aircraft can be said to be one of the simplest flying machines in human aviation history. There is no complicated control system, basically no complex electronic circuits, and even if there is a certain control system, it is simply a hydraulic transmission system. In short, the only thing that restricts its development is the engine. The design of the exterior shape, the structure of the aircraft body, the use of materials, the production and manufacture of parts and components, etc., are not problems. Of course, it is precisely because of this "simplicity" that in another time and space, during World War II, an industrial power like the United States could have a battle with thousands of aircraft. If the technology were too complex, how could there be such large-scale battles?

  "Right, I received a transferred call yesterday. It was a woman who called me, but I didn't know her at all, and I've never revealed my office phone number to anyone unfamiliar? The operator wouldn't have made the mistake easily..."

  "It was just a wrong number, why are you making such a big deal out of it?"

  "What's the big deal? That girl insisted that she was looking for me, and even gave me her phone number, which I had given to her myself. I was puzzled, when did I give a girl my phone number?" Zhang Yusheng said as he turned around, looked at Zhang Yu a few times, and seemed to understand. "So it was you who gave her the number? When did this happen? Tell your big brother about it, we brothers should all find our wives soon, it's time to get lively! What do you say, Yu Ran?"

  Yu Ran, who was sitting in the front passenger seat, had already made up his mind not to participate or speak up when he heard the conversation between the two people in the back. He directly looked out of the window, pretending that he hadn't heard what they were saying. As a result, he didn't expect to be asked about it in the end. "Actually, Commander should also find a girlfriend. Of course, this includes Premier too. You're all not young anymore, and you should have a family."

  "How come I keep hearing that you, Captain Yu, want to settle down?" Zhang Yu said, leaning forward with his head poking out. "Yu Ran, you little rascal, tell me the truth, did you find true love in college? If you really want to get married and start a family, we can give you a long leave of absence, three months not enough, then one year, even if you have a kid before coming back, it's not too late."

  "It's not that I want to get married, it's our deputy captain who has found a partner." Upon saying this, Yu Ran turned his head and seriously said to the two big shots: "Deputy Captain Xie met a girl during last year's Spring Festival family visit leave, and they got along very well. This kind of thing is not good for anyone if it drags on, and both families are urging them, so I'm currently approving his request for leave!"

  "Why didn't you agree with him?"

  Zhang Yusheng, who had not spoken for half a day, suddenly came out with this shocking sentence. As the deputy captain of the inner guard team, who bears heavy responsibilities at all times, how could he say that there is a fake and it's a long honeymoon? Of course, he also realized his mistake, especially after Zhang Yu gave him a big white eye.

  "Don't listen to his nonsense, let Xie Yi that kid write a formal leave application and I'll make sure it's approved. Of course, the premise is that this marriage thing must be done in accordance with reason and law, don't force the girl."

  Zhang Yu naturally knew that his deputy captain, who was playing around all day, had compared gun skills with Lin Xuewen before and lost miserably, blaming the gun for not being as good as others. However, it was precisely this "I am the number one in the world" spirit that made Zhang Yu feel satisfied, so he arranged for a deputy captain position responsible for the daily training of the inner guard team.

  "This is natural, I will let him submit the report as soon as possible." Yu Ran said to this point, as if he remembered something, and then continued: "The other day that girl came to us, she said that she must see Commander again. However, I didn't dare tell you, but I didn't expect her to think of calling..."

  As soon as these words came out, the atmosphere in the car was like the Yellow River's Hukou Waterfall, turbulent and unstoppable. Zhang Yusheng opened his eyes wide and stared at Zhang Yu with a fierce gaze, the meaning of which was very clear: "You little rascal, you actually dared to randomly write my phone number."

  However, Zhang Yu Ke was not intimidated and instead sat down calmly, putting his legs up on the table. Feeling comfortable, he asked Yan Ran, "Did she tell you what she wants to do? Is there something big bothering her again? I'm in charge of the violent organization, if there's a problem, just go to the government."

  "She didn't say anything, just gave me the opportunity to hand you a letter!" Yu Ran said, and then pulled open the zipper from Zhang Yu's briefcase side pocket and took out a letter handed it to him. "The letter, I put it in on Monday. But these days you've been very busy, so I thought this wasn't something important that needed to be dealt with urgently."

  "My grass, you've started receiving love letters! I'm a god." Zhang Yusheng looked at his little brother with a gloomy face as he took the letter and prepared to open it, while he himself had an expression of surprise. After a moment's thought, he quickly asked Yu Ran curiously. "What's the background of that girl? What's her surname and name? Where is she from? What work does she do now......"

  "Can't you shut up!" Zhang Yu quickly scanned the letter and rudely interrupted Zhang Yusheng's gossip. "Take a look yourself, what kind of love letter is this? A denunciation letter actually needs to be delivered to me, have they made a mistake?" Zhang Yu was extremely disappointed as he handed the letter back to Zhang Yu, not forgetting to glare at Yuan Ran with anger. This kid Yuan Ran was just like Xie Yi, full of shortcomings, and still stood there stupidly staring even though he knew it wasn't the time to continue watching the excitement.

  "It seems to be enough to disappoint you, I thought it was a girl's admiration and affection for you, but it turned out to be such a thing..." Zhang Yusheng said seriously, of course, not forgetting to put the letter into his own pocket. However, Zhang Yusheng, who always maintains a relatively optimistic attitude at any time, quickly adjusted his mood and said: "I will deal with these corrupt officials, our future brother's wife has not even passed the door yet and has already made great achievements! Congratulations!"

  "What a wonderful celebration!" Zhang Yu suddenly burst out with profanity in front of everyone, and then continued even more fiercely: "Yu Ran, when you have time, get that dead girl to come out, I really..."

  "You really miss her?" Zhang Yusheng's words were even more outrageous, and he continued to speak without fear: "Then it's even more auspicious!"

  PS: Thank you to everyone who supports me, because of you, I will work even harder, thank you.