Chapter 96 Why do you study it?

The boundary conditions encountered in turbomachinery are among the most complex in the field of CFD.

Since the boundary layer approximation is invalid in many cases, these equations must be solved as a coupled system.

And there are a large number of flow, heat transfer and geometric parameters in the turbomachinery flow: Mach number, rotation speed, intake angle, Reynolds number, Thoma coefficient, Richardson number, Prandtl number, blade pitch, bending torsion, aspect ratio …

On the basis of these parameters, Yao Mengna introduced a jet slit that had never been tried before, further increasing the independent variables of the internal flow field of the compressor and making the simulation more complex.

Therefore, as the computational simulation program was gradually completed, she gradually realized that the process she had just written down on paper was not very feasible in actual operation.

The main reason is that Yao Mengna conducted a simulation attempt with the simplest experimental group and found that the required convergence time far exceeded her expectations.

In fact, Lin Shikuan and others also encountered similar problems, but they were later solved by Chang Haonan, who achieved accelerated convergence through methods such as local time steps, multigrids, and implicit residual smoothing.

However, these things are still a bit complicated for people who are just starting out in the field of numerical simulation. In addition, the time is tight and the tasks are heavy, so in the end, the latter is responsible for writing the relevant programs alone.

This put her in a bit of trouble.

"If you go to your junior fellow student for help..."

Yao Mengna does not object to working with Chang Haonan.

Or rather, she enjoys working with Chang Haonan.

And she also knew that with the other party's ability, it shouldn't take long to solve this kind of problem.

But Chang Haonan is now not only in charge of the digital design team.

There were so many things related to the improvement of Turbojet 14, and his previous management experience was insufficient. During this period, he really felt a little overwhelmed. Yao Mengna was often required to do some things on his behalf, and he was in a state of severe lack of sleep almost every day.

On the other hand, Yao Mengna also has some selfish motives.

Before meeting Chang Haonan, she always thought that she should be a genius.

In fact, most people around me feel this way.

But in recent months, everything has changed.

Chang Haonan's appearance and his exaggerated performance in the wing flutter analysis project almost broke her heart.

But fortunately, I finally adjusted...

At least that's what she thought for a time.

"You are just an ordinary person, and there is nothing wrong with ordinary people."

Yao Mengna told herself this.

But a person's obsession for more than 20 years can't be given up casually.

Although she had accepted the fact that she was not as good as this new student, she still wanted to do something entirely on her own.

"It's not easy to ask others for help with everything...and he has indeed been overburdened recently."

This reason was so impeccable that Yao Mengna easily convinced herself.

She decided to refer to the program Chang Haonan had written before and try to see if she could solve the problem alone.

……

Just when Yao Mengna decided not to find outside help to verify and expand the content of the article, Yu Fei, the tutor of Zhang Donglin, the author of the article, also entered the office of the dean of the college.

Previously, due to the dual limitations of the metalworking center's processing capabilities and their laboratory experimental conditions, Zhang Donglin only spent a month to obtain data results that were not very good.

However, the editors and reviewers of Journal of Aerodynamics showed extraordinary interest and efficiency, and it took more than two months for his paper to be published.

This gave Yu Fei confidence to a considerable extent.

Although Journal of Aerodynamics is not a top journal in China, it is, after all, managed by China Aviation Industry Corporation and sponsored by Beijing University of Aeronautics and Astronautics. Being recognized by its editorial board seems to be equivalent to taking the most critical step.

As long as you can get sponsorship for a separate project, you can definitely show off your skills in this direction.

Zhang Donglin may even get the opportunity to stay in school after graduating with his doctorate and continue to engage in research in related fields with him.

In short, when Yu Fei opened the office door, he was even imagining that he would be promoted to full professor for completing the project...

Then, he saw his dean, who was wiping sweat with a handkerchief, and two other unfamiliar faces, a man and a woman, sitting next to him.

"This is Associate Professor Yu Fei who applied for that subject before."

The dean first introduced to the two people next to him, and then turned to look at Yu Fei: "These two are comrades from the Commission of Science, Technology and Industry for National Defense. They are responsible for reviewing and approving your project application with me."

"Sun Xianmin."

"Ling Na."

The two shook hands with Yu Fei respectively and announced their names at the same time.

The latter, who was immersed in the excitement of having sex just now and has not fully recovered, did not notice that their attitude was a little cold.

The four people quickly moved to a small conference room.

The dean coughed twice and spoke first:

"Associate Professor Yu, let me first report on the general situation of the project you applied for."

"No problem," Yu Fei picked up a piece of chalk and walked to the blackboard.

He had made full preparations before coming here, and he was naturally confident at this time:

"High-performance engines require compressors with higher efficiency and boost ratio, resulting in an increase in stage load and flow loss..."

"In previous experiments, our research team accidentally discovered that grooves on the blade surface can effectively improve the flow separation inside the compressor..."

"We have currently studied the flow of planar stator cascades and tried radial jet slits that open from the suction surface to the pressure surface and chordal slit structures that do not open up the two pressure surfaces..."

"..."

“Relevant research results have been published in the Journal of Aeronautical Dynamics. We believe that opening jet slits on the blades to reduce losses and improve the load bearing capacity of the compressor is a very feasible route, so we hope to get a Grant money to study this.”

After finishing these contents almost in one breath, Yu Fei turned his attention to the three people opposite.

The air became quiet.

The next half minute seemed as long as half a century to Fei.

In the end, it was Ling Na who spoke first:

"Uh... This is an associate professor. According to the requirements, the project application submitted should have a complete literature review."

Yu Fei was stunned:

"I have said before that this phenomenon was first discovered by our research team in experiments. No one has studied it at all. How can we write a literature review?"

Hearing this answer, Ling Na and Sun Xianmin looked at each other, and then continued:

"With all due respect, the correlation of the experimental data you obtained is really poor. It is very difficult to obtain the results you just mentioned..."

"Both of you, in the field of engineering, the correlation coefficient of 0.82 can already explain some problems. It can at least prove the value of continued research." Yu Fei frowned, but still forced himself to answer patiently:

"Moreover, our experimental equipment and the accuracy of blade processing cannot meet the requirements for more precise experiments. This is why I submitted the project in the hope of applying for more funds."

"As you said, the accuracy of your experiment is very poor, so how can you be sure that this result is not caused by the error of the instrument?"

This time, Sun Xianmin, who was sitting opposite, showed a slightly sarcastic look:

"You can't find any literature in the relevant field. It doesn't mean that you are original. It just means that others don't think this kind of research is meaningful at all."

"If you want to apply for a special project, you must at least provide convincing evidence. Otherwise, don't waste everyone's time here. I would say that young people should not be too ambitious and be more down-to-earth. Go and see What are the directions that developed countries are focusing on? Don’t hide in your own world and do useless work!”

Yu Fei clenched his fists instantly.