Chapter 96: Why Do You Study?

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 mechanical flow of the impeller: Mach number, rotational speed, air intake angle, Reynolds number, Thomas coefficient, Richardson number, Plante 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, which further increased the independent variables of the flow field inside the compressor, making the simulation even 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 feasible in practice.

The main reason is that Yao Mengna conducted a simulation attempt with one of the experimental groups with the simplest slit, and found that the convergence time required was far beyond her expectations.

In fact, Lin Shikuan also encountered a similar problem, but it was later solved by Chang Haonan, who achieved accelerated convergence through methods such as local time step, multiple grids, and implicit residual smoothing.

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

This made her a little difficult.

"If you go to the junior...... help"

Yao Mengna is not averse to working with Chang Haonan.

Or maybe she likes to work with Chang Haonan very much.

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

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

There are a lot of things related to the improvement of Turbojet 14, and his previous management experience is insufficient, and he does feel a little lacking in skills during this time, and even often needs Yao Mengna to do some things, and he is almost in a state of severe sleep deprivation every day.

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

Before she met Chang Haonan, she always felt that she should be a genius.

In fact, most of the people around me feel the same way.

But in recent months, everything has changed.

Chang Haonan's appearance and the other party's exaggerated performance on that wing flutter analysis project almost directly broke her heart.

But fortunately, it was finally adjusted......

At least that's what she thought at one point.

"You're just an ordinary person, and there's nothing wrong with ordinary people."

Yao Mengna told herself.

However, where can a person's obsession for more than 20 years be given up casually.

Although she has accepted the fact that she is not as good as this new junior, she still wants to do something completely on her own.

"It's not always good to ask someone else for everything...... And he's really been burdened lately. ”

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

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

……

At the same time that Yao Mengna decided not to find foreign aid to verify and expand the content in that article, Yu Fei, the mentor of the author of the paper, Zhang Donglin, also entered the office of the dean of the college.

Previously, due to the dual limitations of the processing capacity of the metalworking center and the experimental conditions in their laboratory, it only took Zhang Donglin a month to get the data results, which were not very good.

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

This gave Yu Fei confidence to a considerable extent.

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

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

Even after graduating with a doctorate, Zhang Donglin may still have the opportunity to stay in school and continue to follow him to engage in research in related fields.

In short, when Yu Fei pushed open the office door, he was already fantasizing about being rated as a full professor for completing the project......

Then he saw his own dean wiping his sweat with a handkerchief, and two strange faces, a man and a woman, sitting next to him.

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

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

"Sun Xianmin."

"Ling Na."

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

The latter, who had not fully recovered from the excitement of YY just now, did not notice that their attitude was a little cold.

The four of them quickly moved to a small conference room.

The dean coughed lightly twice and was the first to speak:

"Associate Professor Yu, let's report on the general situation of the project you are applying for."

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

He had been fully prepared before coming here, and he was naturally confident at this time:

"High-performance engines require compressors with higher efficiency and boost ratios, resulting in an increase in stage loads and an increase in flow losses......"

"In previous experiments, our research group accidentally found that slotting on the surface of the blade can effectively improve the flow separation inside the compressor......"

"We have studied the flow of planar stating cotyledons, and tried a radial jet gap from the suction surface to the pressure surface and a chordal fracture structure that does not open the two pressure surfaces......"

“……”

"The results of the research have been published in the Journal of Aerodynamics, and we believe that it is a feasible route to reduce losses and improve the load bearing capacity of the compressor by opening jet seams in the blades, so we hope to get a grant to study this."

After almost finishing these contents in one breath, Yu Fei set his eyes on the three people opposite.

The air fell silent.

The next half minute was as long as half a century for Fei.

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

"Uh...... This is an associate professor, and it is required that the submitted project application should have a complete literature review. ”

Yu Fei was stunned:

"As I said before, this phenomenon was first discovered by our research group in experiments, and no one has studied it at all, so how can we write a literature review?"

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

"IMHO, the experimental data you got is so poorly correlated to want to get the results you just said...... Very reluctantly. ”

"In the field of engineering, the correlation coefficient of 0.82 can already explain some problems, at least it can prove that there is value in continuing research." Yu Fei frowned, but still replied patiently:

"Moreover, the experimental equipment on our side and the accuracy of blade processing cannot meet the requirements of more accurate experiments, which is why I submitted the project and hoped to apply for more funding."

"As you said, the accuracy of your experiments is very poor, so how can you be sure that this result is not due to an error in the instrument?"

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

"The fact that you can't find any literature in the relevant direction doesn't mean that you have originality, it only shows 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 come up with enough convincing evidence, otherwise you don't waste everyone's time here. If you want me to say, young people should not be too ambitious, be more down-to-earth, go and see what direction other developed countries are concerned about, and don't hide in their own world to do those useless work! ”

Yu Fei instantly clenched his fists.

(End of chapter)