Rising: Ten Thousand Years Chapter 106: : Completely listen to the scriptures

Li Zhen raised his hand and showed an index finger.

He has mastered the way of lecturing, and he understands that when lecturing, it is easier to impress everyone with physical movements.

"Remember, I'm going to say the theorem. In fluid mechanics, it needs to be applied: continuum assumption, mass conservation theorem, energy conservation theorem, momentum theorem, stress tensor, viscosity assumption. Questions are allowed."

After Li Zhen finished speaking, he put down the triangular ruler and looked up. A piece of people with their heads down and writing notes.

After they finished writing their notes, everyone raised their hands in an instant.

"Hou Qiang asked a question."

Hou Qiang quickly stood up, her tone was extremely fast: "What is a sticky assumption?"

Li Zhen naturally knows that many of these theorems have not been explained to them, but Li Zhen can't remember which ones have been explained and which ones have not been explained, so I will give you a chance to ask questions:

"Viscosity assumption. The stress applied to the fluid and the resulting deformation rate are related to a macroscopic property of the fluid in a certain relationship, which is expressed as the internal friction of the fluid. This is the assumption of viscosity. And due to the viscosity In the case of no external energy supplement, the moving fluid will gradually stop. Viscosity plays an important role in the fluid motion near the surface of the object, so that the flow velocity decreases layer by layer and becomes zero on the object surface. Under certain conditions The fluid can also be detached from the surface of the object. This is the viscosity assumption."

Li Zhen paused every word and spoke as slowly as possible.

The group of 'Shashasha' took a deep breath, not daring to breathe out, and frantically picked up their pens to record.

This paragraph is too long, you have to hurry up, if you don't hurry up, you will forget it later.

At this moment, Lin Xiufeng's eyes were red and bloodshot, and his whole heart was screaming, and he was about to collapse.

He had never felt such a strong pressure. He was obviously observing a class, but when he heard the ground, he was going crazy. Want to roar, slow down, slow down. Slow down, I didn't hear you clearly.

Those other teachers are also going crazy, and their hands are going to break. This rapid writing is simply a kind of torture. Your writing speed must be equal to his speaking speed. When talking about concepts, you can choose key points to memorize, but when talking about theorems, you must not miss a single word.

'Shushasha' don't say that you are absent in class.

In Li Zhen's class, you don't even want to waste the time scratching your head.

"Continue to ask questions. Lan Xunke."

Lan Xunke, the first member of the Kyushu Institute of Physics, hurriedly stood up: "What is the continuum hypothesis?"

"All matter is composed of molecules. Although the molecules are discretely distributed and perform irregular thermal motions. But in a small range, the average value of the fluid molecular microgroups that perform thermal motions is stable. Therefore, it can be It is assumed that the fluid is composed of continuous matter, and the physical quantities such as temperature, density, and pressure are all scalar fields with continuous distribution.”

"Continue to ask questions."

"What is the law of conservation of mass?"

"In a chemical reaction, the sum of the masses of the substances participating in the reaction is equal to the sum of the masses of the substances produced after the reaction. This law is called the law of conservation of mass. It can also be called the law of indestructibility of matter. This is the basic principle that exists universally in nature. One of the laws. I would like to emphasize here that everyone should not confuse the conservation of mass with the conservation of energy.”

Li Zhen picked up the cup and took a sip of water to moisturize his throat: "Simply speaking, mass conservation refers to "mass", that is, the total mass of reactants is equal to the total mass of products; energy conservation refers to "energy", that is, The total energy of the reactants is equal to the total energy of the products plus the total energy absorbed or released. One is mass and the other is energy, so don’t get confused.”

"I ask, what is the law of energy conservation?" Lin Xiufeng shouted.

Li Zhen glanced at him and said lightly: "The content that has nothing to do with this class should be discussed with other people after class."

The words are very euphemistic.

But Lin Xiufeng understood the meaning, that is, if you can't keep up with the progress, don't make trouble. If you don't understand, ask others after class, don't affect my time...

Lin Xiufeng smiled bitterly, he felt that he didn't understand...

These various theorems are unheard of and unseen.

In fact, people from the Kyushu Institute of Physics can understand that they don't need Li Zhen's detailed explanation. Li Zhen told them the concept, and they could understand it roughly. Then after class, we discuss together again, and we will be able to fully understand.

Li Zhen said again: "I will mainly talk about the stress tensor, the applied response, and the force of the force. The concept of the stress tensor is a bit vague for everyone..."

"The forces acting on fluid microelements mainly include surface force and body force, and surface force and body force are respectively...so they are bounded... Stress is obtained by the inner product of a second-order tensor and the normal direction of the surface As described, only three quantities of the second-order stress tensor are independent, so as long as the stress on three different surfaces of a certain point is known, the stress distribution of this point can be determined..."

Everyone is going crazy. They didn't expect the detailed explanation of this stress tensor to be so long. A breathless record.

Hands are about to break.

In the next half an hour, Li Chen began to illustrate and explain those theorems with examples.

And then began to explain fluid mechanics.

"Fluid mechanics not only includes the basic theory of natural science, but also involves the application of engineering technology science. From the perspective of fluid force, it can be divided into hydrostatics, fluid kinematics and fluid dynamics; from different The study of "mechanical model" can be divided into ideal fluid dynamics, viscous fluid dynamics, incompressible fluid dynamics, compressible fluid dynamics, etc..."

"There are many branches of fluid mechanics ~ IndoMTL.com ~ focus on recording. Fluid mechanics covers: hydrodynamics, aerodynamics, osmotic mechanics, explosion mechanics, environmental fluid mechanics, biorheology..."

"Let's talk about the concepts of these branches, let's talk about biorheology first..."

“…”

After the lecture lasted for more than an hour, Li Zhen looked at the time: "Okay, get out of class is over. There is a lot of content in today's lecture, everyone should consolidate after class, and be sure to infiltrate all of today's content within tomorrow. If necessary Where you memorize it by rote, you must memorize it by rote. Get out of class!"

After speaking, Li Zhen took the triangle ruler and left.

Since the transferred teachers seem to be useless, Li Zhen doesn't count on them anymore. It's time to go to class today, so as not to waste another day.

"Thank you Master Li!"

Everyone stood up and bowed.

After Li Chen left, the entire auditorium completely exploded.

Holding the notebook in his hand, Liu Jinghong stood on the table and yelled, "Who the **** understands what biorheology is. I didn't understand that."

"I don't understand one key point. Why is explosion mechanics included in fluid mechanics? How can the shock wave of an explosion be a fluid? Master Li just said it, but I don't understand it. Who the **** will explain it to me? Ah."

"Change a notebook with clear handwriting. Whoever tells me a lesson that I didn't understand before, I will ask him to copy my handwriting and give him a hundred coins!"

"Who will change with me. Who will tell me about the conservation of mass, and I will explain the stress tensor to him."

“…”

The group of teachers were completely dumbfounded, completely listening to the scriptures!

They understand what the study mode of the Kyushu Academy of Sciences is.