MTL - The Science Fiction World of Xueba-Chapter 498 I'll try

Time passed by one minute and one second.

After half an hour.

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

The news sent back in front made the atmosphere in the hall of the command and control center suddenly dignified.

"Old Wu, is there any other way?"

Launch commander Wang Yudao.

Wu Chunmin shook his head and smiled bitterly: "Although the natural circulation pre-cooling mode is simple, it is currently the only measure that can be taken. Even if other methods are useful, it will take time, the launch window is too close, we simply do n’t have enough time to improve A new set of pre-cooling options. "

"If the temperature is 15K, what is the risk of launching?"

"It's hard to say, but it is likely to have an impact on engine ignition."

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

Liu Xuesong said: "The space launch can not be tolerated by any chance, we cannot let a problem rocket go to heaven!"

"In this case, this launch may only be cancelled."

"Even if it is cancelled, trying to find out the failure of the pre-cooling system is probably not a matter of time. This will not only have an impact on the follow-up project of the 921 rocket, but even the progress of the air and space plane project will probably have a great impact.

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

Liu Xuesong glanced at the silent Pang Xuelin, who was a little helpless.

He originally wanted to invite Pang Xuelin to come over and let him look at the 921 rocket, a product representing the highest level in China's aerospace industry. Unexpectedly, there was such a big flaw before the launch.

Wang Yudao: "If it doesn't work, we can only order the termination of the launch procedure and delay this mission."

"and many more!"

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

Wu Chunmin froze for a moment, and said, "Another way is to discharge pre-cooling, that is, before the engine starts, under normal pressure, open the pump front valve and pre-cooling discharge valve, the low-temperature propellant under the pressure of the tank, It flows through the pipeline in front of the pump and the pump, and is finally discharged by the pre-cooling discharge valve in front of the main valve of the propellant. Since the large flow of propellant is discharged in a short time, it needs to be supplemented before the shot to supplement the low-temperature propulsion of the pre-cooling consumption In this way, not only is the waste of propellant more than that of circulating pre-cooling, but there are several problems with discharge pre-cooling. "

"what is the problem?"

"The first problem is that the discharge pre-cooling needs to discharge hundreds of kilograms of liquid oxygen in a short time (about 5 minutes), and the tank must be replenished before shooting. The discharge of large amounts of liquid oxygen requires some corresponding The pipeline and ground treatment equipment. On the contrary, the liquid consumption of circulating pre-cooling is generated in three hours. The whole process is continuous, and it will not bring special operations to the pre-shooting because of pre-cooling. The liquid oxygen returns to the tank, and only the gaseous components are discharged, so no special ground treatment and pipeline equipment are required. Therefore, the use of circulating pre-cooling can greatly simplify the pre-shooting operation and the ground equipment. The second problem 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, causing the temperature of the overall propellant in the storage tank to rise and the quality of the propellant to decline. The expected temperature has an extremely accurate mathematical model for the weight of the propellant discharged. The problem is that the 921 rocket uses a cyclic pre-cooling method, and we want to temporarily change to discharge pre-cooling, then it needs to be very complicated. Calculations, there are only more than two hours left until the launch window is closed. Except for other pre-launch preparations, the actual time left for us to do theoretical calculations is less than one hour. We simply cannot complete in such a short time Such a complex calculation. "

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

At this time, the launching commander Wang Yu interjected: "This is true. Our launch tower has prepared several systems according to different rockets. If the 921 rocket wants to use exhaust pre-cooling, the launch tower can provide supporting equipment."

Pang Xuelin smiled faintly and looked at Wang Yudao: "Commander Wang, can you give me a try? Within half an hour, I will get the amount of liquid oxygen required for discharge pre-cooling, and the launch procedure will continue to advance synchronously."

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

Wang Yu frowned, somewhat hesitant.

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

Wu Chunmin frowned involuntarily, but he was very aware of how terrible the amount of calculation required for the pre-cooling system. During the pre-cooling calculation, it was inevitable to solve the two-phase flow.

The models for calculating and analyzing two-phase flow mainly include homogeneous phase model, split-phase model and slip flow model. Among these models, the homogeneous model is the least difficult and the slip flow model is the most difficult. The exhaust pre-cooling uses precisely the slip flow model. Even with a perfect mathematical model and a computer, Wu Chunmin It takes at least one to two days to complete such calculations, but Pang Xuelin said that he can be sure to complete them within half an hour. How is this possible? !

Several other Daniels who understood the complexity of pre-cooling calculations and Wu Chunmin had similar ideas, but they did not raise any objections.

On the one hand, Pang Xuelin's name is too big.

The two major awards, the Nobel Prize in Chemistry and the Fields Special Prize, combined, almost lifted him to an unprecedented height, and it is an insurmountable peak in Chinese academic circles.

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

Naturally, those super difficult problems in mathematics needless to say, even in the field of engineering, lithium-air batteries, carbon nanomaterials, room temperature superconducting materials and other achievements, UU Kanshu www.uukanshu.com each has a very great impact on the current global industrial system. With a major impact, superconducting materials are even expected to allow Pang Xuelin to win the Nobel Prize in Physics again next year.

Therefore, since Pang Xuelin said that he was sure, no matter how suspicious he was in the hearts of everyone, he could not directly object.

And they also want to see if the gangster's level is as good as the legend.

Soon, the staff in the command hall retrieved the paper money to Pang Xuelin.

Pang Xuelin picked up the paper money and asked Wu Chunmin the parameters of the circulating pre-cooling system while quickly calculating on the manuscript paper.

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

But soon, they gave up.

Because Pang Xuelin's calculations on manuscript paper are line-by-line like a book, let alone those who are engaged in aerospace engineering, even a professional mathematician, will not think about the formula written by Pang Xuelin on manuscript paper for a while.

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