Chapter 1498: Fighting father is risky

As we all know, the three-rotor engine is the pride of British Aerospace Development. Rolls-Royce’s housekeeping skills. Tan Er used it as a condition for negotiating bargaining. The three-rotor engine also paid a price. The company went bankrupt due to various irregularities in the development process and serious budget overruns. If it weren’t for the British government’s rescue, it was nationalized for a period of time and then invested a huge amount. The cost has finally completed the development of the new engine. Rolls-Royce, one of the so-called "Big Three in Civil Aviation Development in the World", may have long been completely cold.
The so-called "rotor" in the aviation field, in simple terms, actually refers to the number of rotating shafts in the engine, the most primitive of course is the "single rotor", all rotating parts are sleeved on this shaft, no matter it is High-pressure compressors, medium-pressure compressors, and low-pressure compressors are still the turbines that drive them. Everyone has the same speed. The representative model is the M53 engine installed on the Gaul Mirage 2000 fighter. This engine has few parts and simple structure. , Easy to maintain, but the performance is also poor, the thrust-to-weight ratio is difficult to exceed 6, and the fuel consumption is high. Compared with the dual-rotor engine, the fuel consumption is at least 20% higher. Therefore, the Phantom series fighters are all small without exception. Short legs.
After the evolution to the dual-rotor engine, the drive shafts of the high-pressure compressor and the medium- and low-pressure compressors were separated. In simple terms, a thin tube was covered with a thick tube, and the two tubes were rotated. Each, everyone does not interfere with each other. With this design, the high-pressure section and the medium-low pressure section can work at their respective relatively appropriate speeds, so the engine's working efficiency is higher and it is less prone to surge.
However, after turbofan engines became popular, and because of the difference in performance required for the two most typical uses of transportation and combat, the technical route took a different turn, the situation changed again.
Compared with combat engines pursuing various extreme operating conditions and transient response capabilities, for the engines required for transportation aircraft, the pursuit of economic and environmental protection indicators such as solidity, fuel economy, high thrust, low noise, and low carbon emissions must be pursued. .
With this as the design goal, engines with large bypass ratios are definitely an undoubted development trend, but even if these engines have adopted a dual-rotor system to distinguish the speed of the high-pressure section and the low-pressure section, there is still another key The parts are not coordinated-the low-pressure fan used for external duct work, that is, the part represented by the word "fan" in the turbofan engine.
The larger the bypass ratio, the larger the diameter of the "fan", and the lower the speed it can withstand.
According to the basic formula of physics "linear velocity=angular velocityradius=rotation speedπradius2", it can be known that at the same rotation speed, the larger the diameter of the "fan", the higher the linear velocity of the fan tip is inevitably Exceeding the speed of sound, I'm sorry, there will be a lot of problems with sonic booms, stalls, shock waves.
This problem is not so obvious on military engines with low bypass ratio, because its bypass ratio is small, the diameter of the fan must also be small, and the linear velocity of the fan tip is also low. This is a big problem on the transport aircraft engine. The diameter of the "fan" can easily exceed 1.5 meters or even 2 meters. In order to save fuel and also have greater thrust, there is a trend of getting bigger and bigger, so Solving the speed of this "fan" is a major issue that the aviation industry has to face.
In this regard, Ivchenko Design Bureau and Rolls-Royce Co., Ltd. came up with the same solution-or we should add another drive shaft to separate the middle and low voltage sections.
From the perspective of working principle, after adopting this system, the physical connection between the fan, medium pressure compressor, and high pressure compressor is completely cut off, and they can all work at the optimal speed. Compared with the dual-rotor system, it can be greatly improved. By reducing the number of work stages, it is possible to control the weight of the engine while improving work efficiency and stability.
The theory is such a theory, but it is really difficult to realize the project. It is so difficult that Luo Luo is ruined...
Of course, Rolls-Royce has now passed the most difficult stage. With the success of the RB211 engine, Rolls-Royce has begun to make efforts in three-rotor engines, and the "Ruida" series of civilian engines have shown a good market prospect.
In comparison, the life of the Ivchenko Design Bureau is much better than that of Luo Luo, because he has a good dad to fight... When he did the most basic research and invested the most, it was precisely the Soviet Russia’s goal to achieve The strategy of the United States is peaceful and does not hesitate to invest the money.
The 1970s was the peak of the Cold War. At that time, it was the talented designer Lotharev who succeeded Ivchenko as the director of the 478 Design Bureau. After proposing a new "three-rotor" engine system, he adopted a relatively cautious approach. In order to verify all the technical feasibility, the D36 engine was born. This engine with a standard thrust of 6.5 tons and a bypass ratio of 5.6 immediately showed good performance. Performance, economy, and development potential have almost dominated all the power units of Soviet-Russian fixed-wing jet aircraft under 100 tons in the same period. The Ivchenko Design Bureau has made persistent efforts to enlarge on the basis of D36 and developed another one. The "PLUS" version, that is, the D18T with a thrust of 25 tons. It is with the support of this engine that there will be a large strategic transport aircraft such as the "An 124" and a large strategic transport aircraft such as the "An 225". Few airports can take off and land.
Of course, this kind of "fighting father" has a well-known hidden risk. Unfortunately, the Ivchenko Design Bureau now has to face this kind of actually very low risk outbreak-father is gone. .
According to Liu Daxiang, the top expert of China Aviation Development, it is a bottomless pit to engage in aviation development. "The three generations of aviation development are poor, and the experiment will ruin a lifetime" is a true portrayal of this industry. Only when Jinshan Yinhai fills in can it be possible to get some Achievements, and China’s own weak national strength in the past few years has also objectively restricted the research process of the Aviation Development. Therefore, it was possible to use the outdated "Speey" developed by Luo Luo in the 1960s as a treasure.
But ah, now the feng shui takes turns, China’s current national strength is obviously prospering, but the original blue star's second overlord Soviet Russia crashed down. After 15 sons each got some inheritance, the second son Uklan was stunned. It was discovered that they couldn't afford such a luxurious toy as Hangfa.
Some students are about to ask, since the Ivchenko Design Bureau is so strong, and there is a factory with mature craftsmanship like Madassic that can produce products, why does it not want to sell aviation to make money? After all, few countries in the world can really produce this thing, and the demand is so large, it should be easy to find a market, right?
It seems to make sense, but in practice it is completely different.