The Science Fiction World of Xueba

Time passed by every minute and every second.

half an hour later.

"Command center, command center, the helium drainage is complete, and the temperature measurement of the pump casing is still 15K higher than the standard temperature..."

The news from the front made the atmosphere in the command and control center hall suddenly tense.

"Old Wu, is there any other way?"

Launch commander Wang Yudao.

Wu Chunmin shook his head and said with a wry smile: "Although the natural circulation pre-cooling mode is simple, it is the only measure that can be taken at present. Even if other methods are useful, it will take time. The launch window is too close, and we simply don't have enough time to perfect it." A new pre-cooling solution."

"If the temperature exceeds 15K, how big is the launch risk?"

"It's hard to say, but it is very likely that it will affect the ignition of the engine."

Wang Yu turned his gaze to Liu Xuesong again: "Old Liu, what do you think?"

Liu Xuesong said: "There is no room for chance in a space launch, we can't let a problematic rocket go to the sky!"

"In this case, this launch may have to be cancelled."

"Even if it is cancelled, it may not be a matter of time to find out the fault of the pre-cooling system. This will not only affect the follow-up project of the 921 rocket, but also have a great impact on the progress of the aerospace aircraft project."

For a while, there was a lot of discussion in the hall.

Liu Xuesong glanced at Pang Xuelin who was standing silently at the side, feeling a little helpless.

Originally, he wanted to invite Pang Xuelin to come and show him the 921 rocket, a product representing the highest level in China's aerospace industry, but he didn't expect such a big mistake before the launch, which made people look down on it for nothing.

Wang Yudao: "If it really doesn't work, we can only order to terminate the launch procedure and postpone this mission."

"etc!"

At this moment, Pang Xuelin's voice suddenly came to mind: "Professor Wu, you just said that there is a way to improve a new pre-cooling plan. What kind of plan is it?"

Wu Chunmin was taken aback for a moment, and said, "There is another way, that is, discharge pre-cooling.

That is, before the engine is started, under normal pressure, the front valve of the pump and the pre-cooling discharge valve are opened, and the low-temperature propellant flows through the pipeline in front of the pump and the pump under the pressure of the storage tank, and finally passes through the pre-cooling valve in front of the main propellant valve. The cold discharge valve discharges. Since the propellant is discharged in a large flow in a short period of time, pre-shooting refill is required to replenish the low-temperature propellant consumed by pre-cooling. In this way, not only is propellant waste much more than cyclic precooling, but also there are several problems in discharge precooling. "

"what is the problem?"

"The first problem is that the discharge precooling needs to discharge hundreds of kilograms of liquid oxygen in a short period of time (about 5 minutes), and the storage tank must be replenished before shooting. However, the discharge of a large amount of liquid oxygen requires some corresponding measures. pipelines and ground handling equipment. On the contrary, the liquid consumption of circulating pre-cooling is produced in three hours. The whole process is continuous, and no special operation will be brought to pre-shooting due to pre-cooling. Moreover, the pre-cooling The liquid oxygen returns to the storage tank, and only the gas phase components are discharged, so special ground treatment and pipeline equipment are not required. Therefore, the use of circulating pre-cooling can greatly simplify the pre-shooting operations and ground equipment. The second question , when the low-temperature propellant passes through the ground filling pipeline for a long time, it absorbs the external heat flow to increase the temperature, and the high-temperature propellant enters the storage tank, which increases the temperature of the overall propellant in the storage tank and reduces the quality of the propellant. The expected temperature requires an extremely accurate mathematical model for the weight of the discharged propellant. The problem is that the 921 rocket uses a cyclic precooling method. If we want to temporarily change to a discharge precooling method, a very complicated process is required. Calculation, now there are only more than two hours left before the launch window closes. Excluding other pre-launch preparations, the real time left for us to do theoretical calculations is less than one hour. It is impossible for us to complete it in such a short period of time. Such a complex computational effort."

Pang Xuelin said: "Is there any treatment equipment for exhaust pre-cooling?"

At this time, Wang Yu, the launch commander, interjected: "That's true. Our launch tower has prepared several systems according to different rockets. If the 921 rocket wants to use exhaust precooling, the launch tower can provide supporting equipment."

Pang Xuelin smiled faintly, looked at Wang Yu, and said, "Commander Wang, can you let me try it? Within half an hour, I will figure out the amount of liquid oxygen to be discharged for the discharge precooling, and the launch procedure will continue to advance simultaneously."

"Half an hour?! Professor Pang, are you sure?"

Wang Yu frowned, hesitant.

Liu Xuesong and Tao Yongchang also looked at Pang Xuelin in shock.

Wu Chunmin frowned even more involuntarily. He knew very well how terrifying the amount of calculation required for the pre-cooling system was. During the process of pre-cooling calculations, it was inevitable to solve the two-phase flow.

The models for calculating and analyzing two-phase flow mainly include homogeneous model, phase separation model and slip flow model. Among these models, the homogeneous model is the least difficult, and the slip flow model is the most difficult, while the discharge precooling adopts the slip flow model. Even with a complete mathematical model and the help of a computer, Wu Chunmin can It takes at least one to two days to complete such a calculation, but Pang Xuelin said that he is sure to complete it within half an hour. How is this possible? !

Several other big cows who understand the complexity of pre-cooling calculations have similar ideas to Wu Chunmin, but they did not raise any objections.

On the one hand, Pang Xuelin's reputation is too great.

The addition of these two awards, the Nobel Prize in Chemistry and the Fields Special Award, has almost lifted him to an unprecedented height, and it is an insurmountable peak in Chinese academic circles.

On the other hand, it is Pang Xuelin's achievements.

Needless to say, those super difficult problems in mathematics, even in the field of engineering, lithium-air batteries, carbon nanomaterials, room temperature superconducting materials and other achievements, each of which has a very significant impact on the current global industrial system, superconducting materials It is even expected that Pang Xuelin will win the Nobel Prize in Physics again next year.

Therefore, since Pang Xuelin said that he was sure, no matter how doubtful everyone was, it was impossible to directly object.

And they also want to see if this boss is as powerful as the legend says.

Soon, the staff in the command hall found the banknotes for Pang Xuelin.

Pang Xuelin picked up the banknotes, asked Wu Chunmin about the parameters of the circulation pre-cooling system, and quickly calculated on the manuscript paper.

Liu Xuesong, Wu Chunmin, Wang Yu and others came behind Pang Xuelin one by one, wanting to see the big guy's calculation ideas.

Soon, however, they gave up.

Because Pang Xuelin's calculations on the manuscript paper are like a scripture, not to mention those who are engaged in aerospace engineering, even a professional mathematician, it is impossible to figure out the formula written by Pang Xuelin on the manuscript paper for a while.

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