It wasn't until Chang Haonan stepped up to the podium and connected his laptop to the projector that the turmoil caused by the entire classroom gradually subsided because of him.

The environment was even quieter than after Liu Hongbo came in.

Because everyone was eagerly waiting to see what the author of the textbook, who was about his own age, could say.

When compiling this textbook, because considering the needs of undergraduate teaching in the future, Chang Haonan added a lot of basic mathematical concepts such as vectors, matrices, and tensors in the previous chapters, which is basically equivalent to re-explaining the content of linear algebra in a general way.

However, since it is now a graduate course, it is certainly not possible to start with this basic part, but to go directly to the basic concepts of engineering analysis and the introduction to the finite element method.

Of course, the first lesson, as is customary, does not involve too much overly complicated content.

"It's a pleasure to stand here and give you this first lesson on the principles and methods of numerical simulation."

Chang Haonan didn't start the intellectual content immediately, but made a slightly light-hearted joke:

"I remember when I was in high school, our math teacher used to say to us, 'Are you or me?' Why don't you come up and talk about it? I guess your middle school teachers have said something like that. ”

"But now, I seem to be really up......"

A joke that only students and teachers understand, made the atmosphere of the whole classroom suddenly cheerful.

Even Liu Hongbo, who had already sat next to the podium and took out a small notebook to take notes, showed a knowing smile.

Although university teachers rarely care about whether students are attending lectures or not, classroom discipline is always maintained.

So he has used similar expressions no less.

As a result, I never expected that not only did a student really go up to speak, but he personally invited him to go up.

However, this will also be the last tenderness that the entire classroom will experience in the next two and a half hours.

Chang Haonan did take into account the gradual process when designing the structure of the textbook, but this does not mean that he will reduce the density of knowledge.

In fact, even if a terrifying 288 class hours have been arranged, if Chang Haonan really wants to evaluate it, the course progress is still relatively tight......

"Generally speaking, the analysis of engineering systems requires us to idealize the system we study into a way that can be solved mathematically, and among the practical problems that you may be exposed to at the graduate level, which are not so complex, we can divide the commonly used models into two categories: the centralized parametric model and the continuum mechanics model, which correspond to what we often call discrete systems and continuous systems......"

Chang Haonan quickly wrote down the board book on the blackboard while speaking.

PPT can indeed make lecturing easier, but at least when Chang Haonan was a student, he always felt that at least for the classroom, board books could not be replaced to a large extent.

Because the action of turning the page of PPT is too simple for the lecturer on the stage, it is easy for people to ignore the student's receptivity.

The effect of the teacher writing on the blackboard is generally better than just putting the PPT once.

As the chalk in Chang Haonan's hand gradually became shorter, the content on the blackboard became richer and richer.

“……”

"Before you start solving a real problem, you can break down the solution process into the following steps. The first is the idealization of the system, then the equilibrium of the elements, the assembly of the elements, and finally the corresponding computational ......"

"This idea is very different for numerical simulation, especially the basic finite element method, and we will demonstrate it with a simple example and a complex example."

"Let's start with this homeostasis problem...... There are three rigid trolleys U1, U2 and U3 on the horizontal plane, and each trolley is connected by a linear spring system, and the displacement of each car and the force in the spring are calculated under the following four load conditions......"

It's actually very easy to make simple things complex and make everyone unaware of them, you just need to use leapfrog ideas and add all kinds of new concepts in one go.

But today's Chang Haonan has long lost the motivation to show off his skills in front of these peers.

The theoretical part of the course does require some talent, but at least 80% of the students in this classroom are from engineering majors.

After all, this is not the era when more than 20 years later, every undergraduate graduate can do CFD simulation.

From a practical point of view, most of them just need to be able to use this tool well, which is already very difficult.

For him, the most important thing is to get the content in a nutshell, and it's best to get everyone in this class to get started with the basics in two and a half hours, or at least understand the significance of numerical simulation in engineering.

Therefore, although his pace is very fast from the beginning, for students who can go to Beijing Airlines University for graduate school, as long as their minds keep following his board book, then there will be no insurmountable gap in understanding.

Soon, the first steady-state problem was explained.

Immediately afterwards, Chang Haonan turned the PPT to the next page, and at the same time showed a smile:

"Next, let's try a slightly more complex problem."

"This is a real practical problem, so if you can't understand it, or can't keep up with the train of thought, it's normal, don't be discouraged, this is just the first lesson, you just need to know that there is such a solution to this kind of problem, it's enough."

Chang Haonan's own projects are basically highly secret, so it is naturally difficult to talk about them directly in class, so he directly "borrowed" from Fang Zhen a problem of calculating the air elastic response and vibration load of wind turbine blades.

Hearing him say this, the students who had just breathed a sigh of relief suddenly tensed up again.

“…… The non-cyclic exponential function is expressed as Φ'(S)=4/M×exp(-S/Tα)=4/M×exp(-t/K1T1)......"

"where the eigenconstant T1-c/a, a is the local sound velocity, and the factor K1=0.75/[(1-M)+πβ^2M^2(A1b1+A2b2)]......"

“……”

After all, it is still difficult for these newcomers who have just entered their graduate careers from the steady-state problem of an almost ideal model to Fang Zhen's graduation project of a fourth-year doctorate.

In addition, Chang Haonan's statement of "it doesn't matter if you can't keep up" just now did make some people's attention not as focused as they were just at this time.

"I'll go, I can still understand a little bit in front of this, and the back feels like it's almost like a book from heaven......"

The buddy who had just accosted Chang Haonan first held a pen in his hand and muttered in a dazed voice.

"It's okay, I felt like a book from the beginning ......"

Narrator: The other person gave him a blank look.

"I can only say that I am worthy of being the editor of the textbook, and I am so terrifying......"

The third person also sighed.

"Have you noticed that Mr. Chang's book has been left there all along, and I haven't brought it with me at all......

Someone finally found a bright spot.

The people around him almost turned their heads to look at the place where Chang Haonan was sitting just now.

Sure enough, a textbook was sitting there.

In other words, the blackboard books just now were all written by him without references......

"It's worthy of being a textbook editor, it's terrifying......"

Another person made the same exclamation.

However, in most people who are at a loss, it is not that there is no great god who can keep up with the train of thought throughout the whole process.

Although the principles of some of the steps themselves may not be well understood because many intellectual things have not yet been learned, it is not easy to understand the overall process.

When Chang Haonan finally demonstrated the calculated aerodynamic/elastic comprehensive equation of motion, in addition to applause and exclamations, one person in the audience raised his hand.

"Is there anything wrong with the student who raised his hand?"

Standing up was a somewhat thin boy with glasses almost half the size of his face:

"In ...... Well, it should be the part that calculates the dynamic stall model correction before the six-page PPT. ”

Speaking of this, someone could still ask such a detailed question, which really surprised Chang Haonan, so he quickly turned the PPT to the page that the other party said.

"Here you set the starting point of the analysis at the root of the blade, set an equivalent angle of attack and an equivalent separation point, I don't understand why this is ......"

Chang Haonan turned his head, glanced at the curtain, touched his chin and thought for a moment.

There are a few students below who have also understood a lot and have begun to guess.

"I guess it's for the next step to be less computational......"

"I think it's because it makes the equations more symmetrical in form, and I know that many geniuses have this fetish."

“……”

"What ...... this?"

Chang Haonan turned around and stood in front of the podium:

"Actually, there is no reason, theoretically, you can actually leave them alone, but I once set two similar dimensionless quantities at random."

"Whoa......

Some people below have breathed a sigh of relief, thinking that they have thought too much.

But then Chang Haonan continued:

"Because it was actually the first project in the world to use this method to do airbomb modeling and analysis, they have learned my method step by step and continued to do it, and now it has become a standard......

“……”

There was silence in the audience.

(End of chapter)