This Liu Lang is still powerful, he has learned this level in a short period of time, no, I have to ask him!

Professor Claire thought as she asked the question again.

"Okay, this is the specific operation of the piston and cylinder, and now I will ask you a few big questions about the engine......... What are the principles and differences between turbojet engines and turbofan engines?"

"Turbojet engine, after the air enters the engine from the intake tract, it is first compressed by a high-speed compressor, producing high-pressure dense air to provide a large amount of oxygen, the combustion chamber is injected with oil to combustion, and the turbine is impacted backwards, and the turbine drives the compressor in front, and the gas flow is ejected from the nozzle to generate thrust.

A turbojet has only one air channel, which is technically called a "duct", while a turbofan engine has two air channels, that is, a turbojet engine is a single-ducted engine, while a turbofan is a double-ducted engine.

The difference is obvious, the larger the bypass ratio, the more fuel-efficient, the better the economy, the high bypass ratio engine has very good energy efficiency at subsonic speed, so it is widely used in passenger aircraft, transport aircraft, etc. ”

"Then let me ask you again, there is a turboprop engine, how does it work?"

Claire asked again.

Liu Lang complained a little in his heart, this question has not much content in the materials at all, just a simple statement, fortunately, he also sent some information to ask other professors.

The essence of the turboprop engine is similar to the turbojet engine connected to a reducer, and drive the external propeller, the fuel efficiency of the turboprop engine is usually higher than that of the turbofan engine, but it is not perfect, one of the reasons is that the turboprop engine has an additional reducer, that is, the transmission gear, the existence of the transmission gear increases the weight of the engine, and the second will bring some power loss. ”

"What about ramjets?"

Claire immediately asked again.

"Professor, the ramjet engine should be the latest engine being studied in the United States, ......right? Well, whether it's a turbojet or a turbofan engine, they have a "compressor" in the front, which is a big one, weighing hundreds of pounds, and it would be great if it could be removed, but the question is, how to compress air without a compressor?

If the aircraft flies faster, then the oncoming air will be faster, and when it is several times faster than the speed of sound, the air is naturally compressed, and the high-pressure air enters the combustion chamber, mixes in the fuel, burns violently and is sprayed back at high speed to get power, this is the principle of the ramjet engine, I don't know how to make it, professor, do you know?"

The ramjet engine is one of the most advanced engines today, and the design and manufacture are the core secrets of the country, and Professor Claire has only mentioned it a little in his previous lectures, but he has not even told everyone the principle, and Liu Lang is only a speculation, and he can imagine that this kind of engine will inevitably be installed on fighter jets, that is, it will reduce weight, and it can obtain power at high speed, and I believe that the latest generation of fighters in the United States will install this kind of engine.

Professor Claire asked five questions in a row, Liu Lang answered them one by one, two of which did not appear in the data at all, Liu Lang thought for a moment and then said the answer according to his strong logical reasoning ability, although it was not perfect, but it basically said the key.

"Haha, you little guy, it's a miracle!"

Professor Claire, who was not smiling, suddenly laughed, and then touched his head, with a smile of relief in his eyes, Liu Lang's performance was too perfect, this is by no means something that can be done by rote memorization of these materials, it is to fully master all the relevant basic knowledge to answer his questions, and it can be done to such a degree in a short period of time, Liu Lang is enough to call it a miracle.

"Jimmy, you're a man who keeps creating miracles, okay, I've decided now, you can get involved in the development of some of my key projects!"

Liu Lang is waiting for this sentence, the core technology is the key, as long as he is exposed to it, even if he doesn't understand it, it doesn't matter, he can at least forcibly write down this knowledge and digest it slowly in the future.

"Professor, thank you for your trust in me, I will definitely live up to your expectations of me, master the knowledge as soon as possible, maybe I can help you in the future!"

"No, no, you have unlimited potential, and your future achievements must be above me, I don't want to learn from Humphrey David!"

Claire waved her hand repeatedly.

Humphrey David is Faraday's teacher, he suppressed this genius everywhere because of his jealousy of Faraday's talent, but genius is a genius after all, not anyone can suppress it, the final result is that after his death, Faraday became a figure who changed human history, as for him, the original achievements were also bleak because of his jealousy.

"Professor, you've won the award, I'm just a student who likes machines, and I can't compare to those big people who changed history!"

What Liu Lang has to do is to keep a low profile, the fewer people who know about it, the better, if those intelligence departments of the US government know about it, I am afraid that the other party will come to investigate him.

", can't a mechanic change history? The Wright brothers haven't changed? Mr. Ford hasn't changed, and Watt, he's a shipbuilder, he invented the steam engine, and he directly pushed the world into the era of the Industrial Revolution, which of these people isn't a big man who changed history? You have the potential to change history now, and if you end up as an ordinary professor, that's your own reason, don't see me then, I won't talk to a person who wastes his talent!"

Claire was angry at Liu Lang's words.

"Okay, Professor, you're right, I'll do what you ask!"

Of course, he would dream that the country's industrial system could independently manufacture an engine of its own, and put it in the self-developed automobile.

But Liu Lang also understands that the engine, which is the pinnacle of the machinery industry, is not something that can be built just by thinking about it.

When Liu Lang was at Huaxia University, someone proposed to build a car engine in the way of imitating German machine tools, such as Santana's engine, and Professor Xiong scolded those students at that time.

Others don't know, but Professor Xiong knows very well that in order to celebrate the 10th anniversary of the founding of the People's Republic of China, the FAW Factory imitated the American Chrysler engine to make Hongqi cars.

After spending several years on a lot of manpower and material resources, it is still a mess, and the final product can only be placed in the museum, and you can imitate the third-rate machine tools in the West, but the first-class automobile engine is simply impossible, at least there is no possibility in China now.

It's not that the students don't understand, Liu Lang also wanted to understand it in depth at that time, so he simply asked Mu Xiaohu to get a Santana from a certain department, and then dismantled it.

After Professor Xiong's detailed explanation, everyone finally realized that this was an impossible task at all.