Chapter 161 The return journey of a wisp of smoke

Author: September Sauce

Chapter 161 The return journey of a wisp of smoke

On the other side, Chengdu.

Chen Nian sat in the office, looking at the thick pile of draft paper in front of him with a frown.

As early as a few days ago, he had entered normal working mode. Now, in addition to his fixed daily study schedule, he spends all his time on the theoretical analysis of the two-stage counter-rotating lift fan.

It must be said that this is an extremely complex task.

Although the F-35's body design and center of gravity data have been obtained, it is still difficult to rely on these things to deduce the precise design data of the fan arranged behind the seat.

Therefore, there is only one thing he can do:

Try to refer to similar aircraft as much as possible and look for clues from them.

During this period, Chen Nian consulted a large amount of information, but there was very little that was actually useful.

In fact, the world's first vertical take-off and landing fighter aircraft appeared in 1950, but the "vertical take-off and landing" method of that thing directly made the engine thrust greater than the power of the body, allowing the aircraft to take off in an upright position. For Chen Nian,

The question is of no help.

Similarly, the second-generation STOVL equipped with additional take-off and landing engines and the third-generation STOVL with tilting engine are also useless, and the design logic is completely different.

The only useful thing is the fourth-generation dual-mode STOVL, but this thing is only available on the F-35.

Chen Nian felt as if he was trapped in an endless loop.

After a busy week, he made no progress in deducing the theory.

So, he secretly made up his mind:

If you are still stuck here within two days, then use the plug-in directly.

The reason why the goal is set to two days later is because according to his current growth rate of source points, it will basically be possible to accumulate enough source points to analyze the core technology of the two-stage counter-rotating lift fan in about 10 days.

If you continue to waste it, you will not have enough time to study, which is equivalent to a net loss of 0.18 points per day.

Thinking of this, Chen Nian couldn't help but sigh.

He reluctantly pushed away the messy papers, stood up and walked out the door, wanting to take a breath of fresh air.

Unexpectedly, as soon as he went out, he bumped into Yang Wei who happened to be looking for him.

"Chen Yunyong has done it!"

Chen Nian was overjoyed when he heard what he said.

"Done? How? When will it be ready?"

"I exchanged it for the EC-130H. Speaking of which, it's all thanks to you to get to the root of this matter."

"It is estimated that it will be in place next month at the latest. At that time, a group of experts in the aviation field will come with him, starting from Shanghai, passing through AH, and flying over by military aircraft."

"What is Haohao's main field?"

Chen Nian continued to ask.

"We have everything, including people who work on finite elements, people who work on aerospace engineering, and people who specialize in materials. A small number of them were brought back from the United States by Chen Yunyong."

"Those people basically worked in private companies before, and they themselves had a certain willingness to return to China. After review, they were allowed to come back."

"By the way, you don't mind this, right?"

Yang Wei asked slightly worriedly.

In fact, for him personally, his origin and past experiences are not too important.

As long as it can pass the review and meet relevant confidentiality requirements, he believes that some overseas service experience can actually be relaxed appropriately.

After all, when they chose to stay there, they did not want to betray, but were simply attracted by better conditions.

This is a very real problem.

After finally learning it, who wouldn’t want to be able to sell their skills at a good price?

Money is the courage of heroes. When everyone is generally in difficulty, pursuing money is not a heinous matter.

What's more, when it comes to treating talents, in some cases in the past, the respect we gave them was not enough. This is a real issue that needs reflection.

Now that the higher-ups have begun to consciously improve remuneration to attract talents, it is even more important to ignore past grudges and show our sincerity.

This also has the chill of buying horse bones for thousands of dollars.

Of course, this is what he thinks, not necessarily everyone thinks so.

Objectively speaking, there are still many people who are prejudiced. They just hope that Chen Nian is not included among these people.

Hearing his words, Chen Nian smiled and replied:

"Of course I don't mind, as long as you follow the rules."

"But this Mr. Chen is really awesome. He makes a lot of money with his beautiful sword, and he can actually kidnap him back."

"No, everyone still has some ideals, and they don't necessarily have to be money worshippers."

Chen Nian nodded in agreement. These days, there are indeed some experts and scholars who still have ideals.

The domestic economy is not good, and there are many temptations abroad. They are really relying on their passion to survive.

"How are you preparing? Is there any progress?"

"No."

Chen Nian answered without any hesitation.

"Do we need to apply for foreign aid? We can talk to Russia. They have similar research."

"No need for now, just give me a few more days."

"Don't worry, Xiao Nian, the progress of this kind of project cannot be measured by the sky."

Yang Wei said dumbfounded.

Good guy, I still wanted to comfort him and tell him that it doesn't matter even if the output is delayed two months, but what did they say?

Give it a few more days.

This is no longer a conversation on the same channel.

The two chatted for a few more words, and Chen Nian walked out of the room to relax. When he came back, his thinking was much clearer.

He spread out the scratch paper on his desk, re-entered the state, and planned to start the deduction from the beginning.

According to the take-off quality of the F-35B aircraft, Male Horse Company adjusted the entire aircraft layout for the lift required for the aircraft to take off. This is the premise of everything.

According to the center of gravity data and the body weight data, the total lift required for the F-35B to take off vertically should be about 18.14 tons. However, this part of the thrust is not entirely provided by the lift fan. Among them, the vector nozzle and attitude adjustment nozzle

It also needs to bear 55% of the lift.

In other words, the thrust provided by the lift fan should be about 8.16 tons.

In order to generate this part of the lift, the lift fan not only needs to have a relatively large pressure difference, but also needs to pass enough flow.

Then, the diameter of the lift fan must be strictly planned.

This part is the hardest.

Chen Nian frowned and carefully recalled the data he had seen in the previous life. He also referred to the thrust of conventional thrust fans, combined with the overall body size of the F-35, and finally determined a number:

Lift fan diameter 1.27m.

This is the only reasonable size in the entire body layout.

In this way, the inlet mass flow rate of the fan should be about 210kg/s.

"Suppose the 0-0 section is the pressure far field, the inlet is the 1-1 section, and the outlet is the 3-3 section. The lift fan inlet Ds=1.27m, the inlet hub ratio Dh-s=0.454, liters

The fan efficiency η=0.87, the nozzle total pressure recovery coefficient σe=0.98, q=204kg/s, assuming the boost ratio is π*”

".q(λ) is the dense flow function, from which we can deduce q(λ), Ma1, p1, T1 on the inlet cross section"

"The lift fan inlet airflow velocity V1 is determined by the continuity equation."

"Compressor efficiency formula is available"

"The final lift expression is"

Chen Nian recited a series of calculation formulas in his mind, and his movements became smoother and smoother.

At this moment, his brain was operating at full capacity, and even beads of sweat began to appear on his forehead.

He is like a super computer, frantically calling up knowledge from two time spaces and two worlds, trying to fuse them together to arrive at the final result.

"So, in order to further accelerate the air, the lift fan outlet is a tapered nozzle, and the constraint conditions can be given: Ma3<1, A3
"In addition, considering the ground effect during takeoff and landing, there is a lift loss in the lift fan, and the general loss rate should be around 50%."

"Traversed the changes in the exit cross-sectional area A3, lift F, and pressure ratio π* with λ within the range of the speed factor λ∈[0,1]"

2.165!
To be continued...