Chapter 2549 Collision of Wisdom 3
"Of course, in fact, the seaiv aircraft is just a compromise between ideal and reality, because we must use engines produced in France, which determines that my aircraft can only use second-rate engines. Secondly, because of the need to consider engine damage during the war Because of this, I could only choose to use an air-cooled engine instead of a liquid-cooled engine. But no matter what, it was still sufficient when it first appeared."
"In terms of power selection, there is a gap of one and a half grades between us and the top level. However, in fact, I have never given up the pursuit of the most cutting-edge aviation performance. In the design of the seav aircraft, I am prepared to use the British Eagle liquid-cooled engine, and in order to adapt to this engine, my team and I optimized the shape and structure of the entire aircraft. It was originally prepared to deal with your country's later more advanced aircraft, but the war was over. It can only stay in the prototype stage forever." Marcel said with a sigh.
"So, now you're going to use a Daimler Benz engine to resurrect him?" Heinkel asked.
"Well, yes, if possible, I also hope that this bidding can revive my factory." Marcel said.
"It depends on your ability. By the way, in this bidding, both the Bavarian government and giants such as Junkers and Fokker will come up with their own new products." Heinkel said.
"In addition, I would like to ask, has your country found in aviation flights that using gasoline from different origins will lead to a relatively large gap in the flight performance of the aircraft?" Marcel asked.
"Can you be more specific?" Heinkel asked.
"Of course. For example, when our aircraft uses domestic fuel, it is easy to cause detonation. You and I know very well that under normal circumstances, the operation of the cylinder should be like this. As the piston pushes, the cylinder The mixture of air and gasoline inside begins to compress. When it reaches a certain level, the spark plug begins to ignite. At this time, the gas ignites and expands. This process starts from the spark plug and then spreads around. But sometimes, when the piston moves to the ignition point Previously, the oil-air mixture inside the engine would ignite in advance! However, it would cause the cylinder to vibrate. At least it would affect the engine output, and at worst it would directly lead to the engine being scrapped," Marcel said.
"We have also encountered this problem. Generally speaking, it should be an oil problem." Heinkel said. "It rarely happens with our engines at low compression, but it's more common in some high-compression models, and for that, we had to add something."
"Yes, this problem is not obvious when the compression ratio is low, but it becomes more serious when a high compression ratio is used. At present, the only thing the French Air Force can do is to use it when high power is required. You can inject a mixture of water and methanol into the cylinder, but this problem is just an idea and has not been completely solved," Marcel said.
In fact, the so-called engine knocking problem was discovered very early in history, and for this reason, engineers used high-speed cameras to observe the process and causes of knocking. Then why did people measure the anti-knock performance of gasoline and specially put forward the so-called octane number concept? What does this concept mean? That is to say, a mixture of n-heptane and isooctane is used to describe the anti-knock value of gasoline. As for why we chose these two substances instead of others, the reason is very simple. The volatility of these two substances is almost the same. No matter how they are mixed, the ratio will not change.
Well, what does the so-called No. 87 fuel in history mean? This means that the anti-knock ability of this gasoline is the same as a mixture of 87% isooctane and 13% n-heptane, so the greater the isooctane ratio, the better the anti-knock effect. It also means the fuel performance it represents is better.
So now the question arises, how did the so-called No. 130 fuel in the war come out? After all, it’s only 100 when it’s completely octane! the reason is simple,
Add anti-knock agent to improve it! In fact, the so-called No. 130 fuel no longer means the so-called isooctane ratio. Historically, the best additive that appeared before World War II was the tetraethyl lead series.
Well, maybe someone wants to ask, why does adding water and ethanol prevent detonation? The reason is simple. Adding the water and ethanol mixture first will cause the temperature to decrease. One of the reasons for knocking is that the temperature and pressure cause combustion to start early. On the other hand, ethanol has better anti-knock performance, while water vapor is It won't explode... Therefore, after adding ethanol and water, the anti-knock performance of the mixture in the cylinder will naturally be greatly improved!
However, in this current dimension, neither the Germans nor the Americans have evolved to the point where they have begun to use various additives to improve fuel performance. Even the simplest and most crude emergency method of spraying a mixture of water and ethanol in later generations has not yet been developed. Just thinking about it without doing it. So what is the solution for the participating countries? The Germans' method was very simple. Because they found that Romani's fuel quality was relatively high, they directly restricted the use of crude oil produced in Romania for aviation engines and tried to improve the level of refining. What about the Allies? The solution is also very simple, just limit the power... When a certain temperature and pressure are reached, knocking will occur, so wouldn't it be enough to reduce the power?
"A mixture of water and ethanol to improve temporary knock performance is only an emergency solution. In fact, we should start from the perspective of fuel to improve knock resistance, so we are currently trying to synthesize some kind of additive to improve this performance. . But it takes time and a huge investment," Heinkel said.
In the end, after the discussion, Heinkel still spoke highly of Marcel. After all, the latter did have very profound knowledge in aviation theory, and some of his methods were also very good. This is the most valuable thing!
There are also unique technical details, such as the shock absorbers specially installed on the two large-caliber machine guns placed inside the wings during the subsequent visit to reduce the impact of the vibration of the machine guns on flight during shooting.
"Marcel Brochet is a very good aircraft designer. He definitely represents the highest level of the French aviation industry. If such a master can join the Bavarian aviation industry, it will undoubtedly be beneficial to our career. Very important role," Heinkel wrote in a letter to the crown prince.
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