Some comrades may say that since the engine must be supercharged in order to pursue high-altitude and high-speed performance, then what is the difficulty of supercharging?

Not to mention, this question is really not simple. Because the pressurization method of different engine mechanism types is different. Let's start with a brief introduction!

As mentioned earlier, there are three main configurations of piston aero engines - star, V, and inline. The most common use in World War II was the star and V-engine. As mentioned earlier, these two engines represent two different forms of cooling - air-cooled and water-cooled.

The star-type air-cooled engine is more cost-effective when the power is small, and when the power reaches a certain range, such as about 1500 horsepower, it has no advantage over the water-cooled engine.

This lack of advantage is not only reflected in the full weight of the engine, but more importantly, in the way of supercharging. In a radial engine, each cylinder has to be inlet and exhausted separately because the head of each cylinder is facing outward, which creates a great obstacle for the application of superchargers.

Let's put it this way, the star-shaped air-cooled piston engine can only use the supercharged method due to its structural limitations! In fact, even if it is enough to use mechanical supercharging, as for turbocharging, think about it, it is very fatal to install compressors for the intake circuit of each cylinder, and turbocharging also requires the installation of exhaust gas turbines, so that the two sets of equipment to install the star engine is enough for the designer to lose his hair, and even if it can be installed, the cost and weight are almost unacceptable. The complexity and maintainability of the system is even more outrageous!

That said, star-shaped air-cooled engines are inherently unsuitable for turbocharging. Some comrades may say again, since it is not suitable for turbocharging, then there is no need to use it. Isn't there still supercharging?

That's right. However, there is still a big difference between the mechanical supercharging method and the turbocharging method. The potential is not the same. To put it simply, the advantage of the supercharging method is that it can play a role at any speed of the engine, and the throttle response is fast, but the disadvantage is that it has to eat a lot of engine power, and the weight of the system is relatively large. In other words, the supercharging method will cancel out a considerable part of the power, which is really costly for the piston engine, which is difficult to increase every little bit of power.

This is not the case with turbocharging systems, which do not draw power directly from the engine. Instead, an exhaust gas turbine is installed in the exhaust circuit of the engine, and the power recovered from the exhaust gas is used to drive the compressor to complete the pressurization. This has little effect on the power of the engine (engine output decreases due to the increased exhaust back pressure, but it is much smaller than mechanical supercharging). Not only does the engine consume less power, but more importantly, the turbocharging system is lightweight and reliable.

Of course, turbocharging also has a small problem, that is, the exhaust gas turbine must reach a certain engine speed before it can start working properly, and when the engine speed is low, the turbocharger is actually "resting". That is to say, unlike mechanical supercharging, turbocharging works linearly, and its throttle response is relatively slow.

However, this small disadvantage is that the flaw is not hidden. For fighter jets and interceptors, when they climb to high altitudes, the turbocharging system will definitely work properly, and this is not a problem at all.

However, turbocharging is more suitable for liquid-cooled engines (there is no problem with using mechanical supercharging for liquid-cooled engines), and air-cooled engines can almost be said to have nothing to do with turbocharging. As a traverser, especially Li Xiaofeng, who is preparing to vigorously develop long-range aviation and a strategic air force, the only way to escort high-altitude long-range bombers is a V-type engine equipped with liquid-cooled turbocharging, not an air-cooled star-shaped engine.

And to be honest, the Soviet Union did not give full play to the advantages of liquid-cooled engines in World War II, and the relatively successful AM-38 liquid-cooled engine was equipped on a large scale to the Il-2, a model that actually does not need a liquid-cooled engine, and the MiG-3, which urgently needs the AM-35, can only stand aside and stare dryly.

Especially in terms of pressurization technology, the Soviet Union is not generally rotten, large-scale applications are mechanical pressurization, fortunately the opponent Germany does not have high-altitude strategic bombers, most of the air battles are triggered by the low-altitude Stuka and the Black Death in the attack of both sides, so that the Soviet Union meets the B17 and B29 aircraft groups of the US imperialists, and it is really no way.

This kind of situation must be what Li Xiaofeng does not want to see, and he must not let the Soviet Union's high-altitude strategic bombers bravely enter the hinterland of Germany's air defense without escort, right? That's almost the equivalent of death.

Under Li Xiaofeng's reminder, Arksnis quickly realized that if the Red Air Force was to become a strategic force, fighters and interceptors with excellent high-altitude performance must be developed.

Under the strong demand of the Air Force, the designers naturally have to take action, and after some comparison, in order to meet the high-altitude performance, the air-cooled engine is naturally not enough to see (for example, the B-29's Wright R-3350 air-cooled engine is quite unreliable, and it is easy to overheat under combat load, and the B-29D with Pratt & Whitney's R-4360 is used to solve the problem.) ）

After some comparison, the designers generally believe that the air-cooled engine is more troublesome whether it is applied mechanical supercharging or turbocharging, and in the long run, a liquid-cooled engine engine with a relatively high power-to-weight ratio and has applied supercharging means (12Ycrs uses two-stage mechanical supercharging) is naturally very valuable to introduce. This is not only a reference for the AM-34 that does not meet the performance standards, but also a mature mechanical boosting system, which can be said to kill two birds with one stone!

For veteran designers, especially those like Polikarpov, liquid-cooled engines are more in line with their pursuit of high altitude and high speed, and naturally they will support Li Xiaofeng's initiative to introduce French engines.

Don't underestimate the energy of Polikarpov's group of designers, who were still very strong with Lenin and Trotsky, especially on technical matters, and the two mentors were still more willing to trust the opinions of professionals.

Obviously, this time, the opinions of technical experts and military experts are highly conflicting, so which side should be accepted?

This is not a simple question, and both Lenin and Trotsky were aware of it. This is no longer a simple technical and military issue. In fact, it is a political problem within the military. It's obvious. Li Xiaofeng is carrying Tukhachevsky, once the winner is decided, it means that one of these two people will have to pay a heavy price.

Both Lenin and Trotsky had to be cautious about this. For Trotsky, in particular, he was quite embarrassed. Why is it difficult? Because he has always respected experts and technical streams, he had previously made trouble with Lenin over the Lysenko problem, which added a lot of prestige to him.

This time, Tukhachevsky's opinion is the opposite of that of the experts. Moreover, it is not one or two experts, but almost the entire aviation industry that unanimously agrees with Li Xiaofeng's opinion, and supporting Tukhachevsky is tantamount to slapping all experts in the face, and Trotsky must weigh it.

Trotsky had an opinion on Tukhachevsky's approach, wasn't it the introduction of French engine technology? What a big deal, there is a lot of money in the airline, what is this money, and Li Xiaofeng has a good reason, the technology of the French is indeed worth introducing. Why bother with such a trivial matter?

In Trotsky's view, there were many ways to slap Li Xiaofeng in the face. There is no need to be so petty, you kid doing this is tantamount to a full-scale declaration of war. I have to die to die!

In fact, Tukhachevsky did not expect that things would develop to this point, and he did not expect that the vast majority of aviation experts would be on Li Xiaofeng's side. It can only be said that Tukhachevsky is too ignorant of politics and too ignorant of human feelings.

In the past ten years, Li Xiaofeng has made great efforts in the field of technology, when the Cheka arrested people indiscriminately, it was he who said good things to save people for aviation experts, and the welfare and funding of experts have always been his help to find a way, it can be said that in this decade, most technical experts owe him favors!

And now, aviation technical experts are more optimistic about liquid-cooled engines, Li Xiaofeng is more in line with their tastes, coupled with the previous relationship, it is obvious which side to support.

But now, Tukhachevsky can't admit defeat, because admitting defeat means ruining miè, not to mention that he doesn't think he will necessarily lose!

Why did Tukhachevsky have such confidence? The reason is simple: technical cooperation between Russia and Germany has been going well in the past ten years, and he believes that the problem of the AM-34 will soon be solved with the help of German technical experts. And as soon as the technical problems of the AM-34 were quickly resolved, there would be no excuses for the introduction of French power.

In Tukhachevsky's view, even if Polikarpov and a group of soil experts support Li Xiaofeng, compared with German experts, soil experts are soil experts, and the Germans will solve a qiē problem!

"Well, then wait and see, if the problems faced by the AM-34 can be solved quickly, then there is really no need to introduce French technology!"

After some reflection, Trotsky reluctantly agreed to Tukhachevsky, giving him invaluable support. In this way, Lenin had very little choice, and to support Li Xiaofeng would be tantamount to a slap in the face to Trotsky, who, in view of the recent tensions between the Trotskyists and the Leninists, would not be able to provoke Trotsky again at this time.

But it was impossible to get Lenin to support Trotsky, and Li Xiaofeng was his man anyway, how could he turn his elbow outward?

After going back and forth, the matter was deadlocked, Lenin chose not to express his opinion, he was ready to let time speak, if the Germans really helped to get the AM-34 ready, then naturally there was nothing to say, when the time came, just help maintain Li Xiaofeng, so that the Trotskyists could not beat the water dogs. And if the AM-34 can't be done within the allotted time, then all he has to do is agree to the introduction of French technology, and as for Tukhachevsky, hehe, that's a matter for Trotsky to worry about.

So will the AM-34 be able to solve the problem quickly? The answer given by history is no, and the AM-34, equipped with TB-3 bombers, was full of problems, and directly led to the failure of the first three finalization of the TB-3. It was not until 1935 that the AM-34 began to be stable and reliable. And the AM-34FRN (that is, AM-35), which later shone brightly, was not completed until 1938.

That is, for more than a year, almost two years, the AM-34 was practically unreliable, especially after the constant accidents on the TB-3. The pressure on Mikulin and AM-34 will be very high. Tukhachevsky, who naturally supported the AM-34 against the introduction of French technology, will also Alexander.

And that's not all. Tukhachevsky's confidence in the AM-34 comes mostly from Germany, and he hopes that German technicians will help solve technical problems. But he really made a mistake, since Hitler came to power, the honeymoon period of technical cooperation between Germany and the Soviet Union, which lasted for ten years, came to an end, a large number of cooperation projects were terminated, and German technicians were recalled one after another. Tukhachevsky's expecting too much help from the Germans would practically not work.

Li Xiaofeng naturally knew this, and soon the mustache would pour a basin of cold water on Tukhachevsky. By 1934, trade between the Soviet Union and Germany would fall sharply, approaching zero indefinitely, and it was not until 1938 that the mustache was preparing for an attack on Poland, the need to paralyze and the cooperation of the Soviet Union was relaxed again. It can be said that from 1933 onwards, the USSR could not count on the Germans at all.

"Then you mean, we're just waiting to see Tukhachevsky's jokes?" Yakov asked worriedly.

As a close assistant to Li Xiaofeng, Yakov could obtain a lot of unknown information, and a certain immortal was also willing to reveal some historical developments to him, under the influence of Li Xiaofeng, Yakov was extremely worried about the future direction of Germany, for example, in the Reichstag arson case, the Nazis framed the Communist Party has profoundly demonstrated their hostility to Communism.

The USSR as the big brother of the world Communist Party. Being hostile to the Germans almost meant war, and what worried Yakov even more was the attitude of the British and French. These two countries were simply indulging the Germans, and the attitude of the troubled people that was sometimes revealed was even more alarming.

In Yakov's view, it could almost be said that a new world war was inevitable, perhaps five to ten years at the slowest possible. And now the USSR was simply not prepared for it, and there was not much time to waste in this situation.

For example, in the field of engines, it takes three years for an engine to be mass-produced from the introduction of technology, and the introduction of the 12Y series in 1933 can be mass-produced in 1936, and it can even be improved in a targeted manner, and when the AM-34 does not progress well, it may take a lot of valuable time to introduce it!

Based on this, he must remind Li Xiaofeng that he must not wait for Tukhachevsky to make a fool of himself with the mood of watching a joke, otherwise it will definitely be the Soviet Union that will make a fool of himself in the end.

In fact, Li Xiaofeng didn't mean to read the joke, he knew better than Yakov how precious time is, and the introduction of the 12Y series a year earlier has a completely different meaning compared to a year later. For him, the introduction of the 12Y series is a must, but given the current complex shape, it may be difficult to introduce it directly, is there any way to bypass the obstacles set up by Tukhachevsky?

"Do we have the funds now to build a new line of piston engines?" Li Xiaofeng asked suddenly.

Yakov immediately understood what someone meant, it was unlikely that the 12Y series would be introduced immediately in the name of the Soviet government, and the only feasible thing was probably to introduce technology for production in the name of NORINCO.

Yakov immediately replied: "There are no problems with the funding!" ”

Li Xiaofeng nodded slowly, but he did not immediately agree to do so, because in his plan, there is no need for NORINCO to invest in aviation gasoline engines, because this industry will soon be eliminated, and in the mid-to-late forties, the future will belong to jet engines, and it is too wasteful to invest in aviation gasoline engines.

In Li Xiaofeng's previous planning, NORINCO focused on diesel engines in the engine field in World War II, striving for a breakthrough in both low-speed and high-speed diesel engines, and must occupy a world-class position, so he invested in B2-34.

And now, because of Tukhachevsky's interference, a production line for aviation gasoline engines is launched, is it cost-effective?

In fact, it is not only the production problem that makes Li Xiaofeng difficult, but also the conditions of the French, to buy 12Ycrs, you must first purchase 500 12Ybrs, who will use these 12Ybrs engines? The I-16 used the M-25, and it was impossible to purchase the 12Ybrs, and with Tukhachevsky's determination to make trouble, the 12Ybrs would never be allowed to enter service with the Red Army. Isn't the bought 12Ybrs scrap metal?

Although Li Xiaofeng is rich, he is not so loser, if he doesn't find a user for 12Ybrs, he really can't make up his mind to introduce the 12Ycrs engine. But who is the user of 12Ybrs? The military must be out of play, so civilian?

Li Xiaofeng immediately smiled bitterly, there was a ghost civil aviation market in the Soviet Union, and people were thankful that they could get on the train when they went out, but they couldn't even think of airplanes. And the USSR also did not have civilian aircraft, and the paratroopers made cameos with bombers such as TB-1 and TB-3......

Bomber? Transport?

A spark suddenly flashed in Li Xiaofeng's mind, he seemed to think of something, and after scratching his ears and cheeks for a long time, he suddenly asked, "Yakov, what day is it?" ”

Yakov was also surprised, and replied in a daze: "April 15." ”

April? Li Xiaofeng scratched his head again, he remembered that Douglas's DC-1 seemed to have made its first flight in July 1933, and according to the time schedule, the DC-1 should have been manufacturing prototypes.

Why did Li Xiaofeng think of DC-1? The reason is very simple, as the most successful model in the entire thirties, the DC-1, which was developed from the DC-3, was an unprecedented success, and even the Soviet Union introduced the DC-3 (Li-2 transport aircraft). If we can cooperate with Douglas to introduce some DC series transport aircraft equipped with 12Ybrs engines, it seems to be a problem?

At least Li Xiaofeng remembers that the original DC-1 was equipped with a Wright SGR-1820-F series engine with 710 horsepower, while the 12Ybrs power had 760 horsepower. It can be fully installed, and the liquid-cooled 12Ybrs engine may be a little heavier, but the modified engine compartment can completely reduce wind resistance, and the original performance of the DC-1 can be maintained.

As soon as he thought of this, Li Xiaofeng couldn't sit still, and he immediately ordered: "Contact Douglas Company immediately......" (To be continued......

PS: Bow and thank zz120, drink a thousand cups and people are not drunk, kill potatoes and Juventus comrades in seconds!