Refining Star River

"Navy-Stokes equation!" Tang Xue gritted her teeth.

"You...you are really ruthless!"

"You let me out." Tang Xue's flawless face showed a trace of pride.

"Compared with the world-renowned problems such as Riemann’s Conjecture, Fermat’s Last Theorem, and Goldbach’s Conjecture, the Navier-Stokes equation has a very low sense of existence. Even in the ancient Earth era, Few people mention it. The most important reason is that this problem is really not easy to understand, especially for ordinary persons. Even the PNP problem at the top of the list can be figured out by ordinary persons, but it is difficult to understand. The V-Stokes equation, which is why Minke rarely touches on this issue." Zhou Sen said with a bitter smile.

"I don't ask you to untie it, just talk about it!" Tang Xue felt a bit too much.

"It’s okay to say a few words. The description of this problem in human history is actually very obscure: "The undulating waves follow our boat that is winding in the lake, and the turbulent air current follows. With the flight of our modern jet aircraft. Mathematicians and physicists are convinced that both breeze and turbulence can be explained and predicted by understanding the solutions of Navier-Stokes equations. Although these equations They were written in the 19th century and we still have very little understanding of them. The challenge is to make substantial progress in mathematical theory so that we can unravel the mysteries hidden in the Navier-Stokes equation.' There is no beginning and no end to the words. Even in this passage, it is difficult for you to guess what the problem is, and it reveals a metaphysical problem."

"Be specific!" Tang Xue His eyes became surprised.

"The Navier-Stokes equation was not proposed by a single person. In ancient Earth in 1775, the famous mathematician Euler, yes, there is nothing wrong with the Four Great Heavenly Kings Euler in mathematics. Now he has come to blend fluid mechanics again. In the book "General Principles of Fluid Movement", he derived a set of equations based on the force and momentum changes experienced by the fluid when inviscid fluid moves. The equations are as follows: (axD+ bxD+c)y=f(x). This is the most important basic equation in inviscid fluid dynamics. It refers to the differential equation of motion obtained by applying Newton’s second law to inviscid fluid clusters. It describes the ideal fluid The law of motion. It has laid the foundation for ideal fluid mechanics."

"Viscous fluid refers to a fluid whose viscous effect cannot be ignored. Actual fluids in nature are viscous, so actual fluids are also called viscous fluids. Flow physique The nature of friction between the flowable layers between points due to relative motion and resists relative motion... It can be said that the Navier-Stokes equation is generated by many scientists and engineers, and it is a set of descriptions like liquid and The equations of fluid matter such as air. These equations establish the relationship between the rate of change of the particle momentum of the fluid, the change of pressure acting inside the liquid, and the dissipation of viscous forces and gravitational forces. These viscous forces are generated by the interaction of molecules. It can tell us how viscous the liquid is. In this way, the Navier-Stokes equation describes the dynamic balance of forces acting on any given area of ​​the liquid."

"In fluid mechanics, there are many Equation, but many equations are related to the Navier-Stokes equation. The Navier-Stokes equation can be said to describe most of the conditions in the field of fluids. Of course, the equation also has its scope of application. The equation only Applicable to Newtonian fluid. What is Newtonian fluid? Simply put: the fluid whose shear stress at any point has a linear function relationship with the shear deformation rate. Generally, high-viscosity fluids do not satisfy this relationship, indicating that Newtonian fluid A simple example with non-Newtonian fluids is the well-known siphon phenomenon. At low viscosity, the suction port must be below the page for siphoning to proceed, but for non-Newtonian fluids with high viscosity, the suction port must be higher than the liquid level. , Its siphoning can still be carried out because the viscosity is too big..."

"What applications of the Navier-Stokes equation?" Tang Xue asked Zhou Sen with an infatuated look.

"For engineering applications, Newtonian fluids are still handled in most cases, or can be approximated as Newtonian fluids. It can be said that this equation plays a fundamental role in fluid mechanics, but it also plays a The decisive role...Although the Navier-Stokes equation can describe the motion of fluids in space. The solution of the Navier-Stokes equation can be used in many practical applications. For example, it can be used to simulate weather and ocean currents. , The water flow in the pipe, the movement of the stars in the galaxy, the airflow around the airfoil. They can also be used for the design of aircraft and vehicles, the study of blood circulation, the design of power stations, the analysis of pollution effects, etc."

“However, the current theoretical research on the solution of the Navier-Stokes equation is still insufficient, especially the solution of the Navier-Stokes equation often includes turbulence. Turbulence, also known as turbulence, is a kind of fluid flow. State. When the flow rate is very small, the fluids flow in layers without mixing, which is called laminar flow or tablet sugar; gradually increase the flow rate, and the fluid streamline begins to oscillate. The frequency and amplitude of the oscillation increase with the flow rate. But increase, this kind of flow condition is called transitional flow; when the flow velocity increases to a large extent, the streamline is no longer clearly distinguishable, there are many small vortex in the flow field, called turbulence, also called turbulence, turbulence or turbulence Flow. Although turbulence is very important in science and engineering, the disorder, energy consumption, and diffusion of turbulence are still one of the unsolved physics problems."

" , The basic properties of the solutions of many Navier-Stokes equations have not yet been proven. Because Navier-Stokes equations rely on differential equations to describe the motion of fluids. Unlike algebraic equations, these equations do not seek to establish what is being studied. The relationship between the variables, and seek to establish the relationship between the rate of change or flux of these quantities. In mathematical terms, these rates of change correspond to the derivative of the variable. Among them, the simplest case is the ideal fluid with 0 viscosity The Navier-Stokes equation shows that acceleration is proportional to the derivative of internal pressure..."

"Note that the official statement of every mathematical problem in human mathematics problems is except for the PNP problem. It is written by Fields Medal winners who have made achievements in this field or on this issue to ensure that the problem can be refined and summarized, thereby ensuring the rigor of the problem, and the PNP problem is related to the computer, so the official statement is Written by Turing Prize winner Stephen Cook, the existence and smoothness of the Navier-Stokes equation. An official statement written by Charles Feifman. If you have no way to understand it, you can simply understand it as a scientist hopes that Find out the general solution of the Navier-Stokes equation, that is to say, prove that the solution of the equation always exists. In other words, can this set of equations describe any fluid, under any initial conditions, at any point in the future The situation."

"Can it be solved?" Tang Xue was surrounded by clouds and mist by Zhou Sen.

"This is difficult...a set of Simultaneous Equations that are difficult to clarify with mathematical theories. You also need to prove that the solution of this equation always exists. This has caused many scientists to collapse. There are only about one at present. More than a hundred special solutions were solved. And the mathematician Jean Leray proved the existence of the so-called weak solution of the Navier-Stokes problem, which satisfies the Navier-Stokes problem on the average, but It cannot be satisfied at every point. Since then, the research on the Navier-Stokes problem has stagnated, so it is also called the most difficult mathematical or physical formula... In the process of constantly solving the Navier-Stokes equation, countless new mathematical tools and mathematical methods were born, leading the continuous development of mathematics. This is the meaning of these difficult conjectures."

Zhou Sen finished speaking and looked at the two siblings with a calm expression on his face.

Tang Xue and Tang Changfeng both looked at Zhou Sen with dull faces, especially Tang Xue with incredible expressions.

Although Zhou Sen didn't solve the equation, he knew enough about it to make Tang Xue look at him with admiration.

What impressed Tang Xue most is that Zhou Sen has a very comprehensive understanding. Without in-depth research, he would never have such a deep insight.

Of course, Tang Xue doesn’t know. Actually, in the five major Star Domains, this equation has been solved. It’s just that Zhou Sen doesn’t want to be greedy in this planet, so he just explained some hard things. Once again, but he didn't expect that, he just repeated some common sense things to make Tang Xue shocked.

The retelling of Zhou Sen’s explanation has paid off. Now, Tang Xue has completely believed that he is a scientist, because Zong sect, let alone telling, can’t understand even some of the vocabulary in it, such as "Laminar flow", "turbulent flow", "turbulent flow", "turbulent flow", and "turbulent flow", these highly professional vocabulary, can never be said by that decadent guy.

"Can you really overthrow the West Asian Empire?" Tang Xue said hopefully.

"Yes, but..."

"But how?" Tang Xue asked hurriedly.

"I will design some weapons, you have to help me build them."

"Our supply chain has been broken, and the machines we can run are now becoming fewer and fewer. ..." Tang Xue hesitated.

"It doesn't matter, as long as you have the venue and resources, I can help you make equipment."

"Are you alone?" Tang Xue said with an incredible expression.

"I am definitely not the one, but as long as you have a team, I can teach you!" Zhou Sen looked affirmed.

"We have encountered many difficulties, such as transportation is a problem. At present, all key intersections have checkpoints. This has caused us not only to break the supply chain, but also to transport some materials..."

"No problem, what do you think this is?" Zhou Sen pulled out the flying skateboard hidden under the sofa.

"What?" Tang Xue and Tang Changfeng glanced at each other, neither of them knew what this thing was.

"This is a flying skateboard."

"What is a flying skateboard?" Tang Xue asked blankly after seeing a flying skateboard for the first time.

"Look!"

Zhou Sen stepped on the flying skateboard, leaned slightly, the flying skateboard took off in the living room, and then flew in the small space .

Tang Xue looked at Zhou Sen in midair enthusiastically, and Tang Changfeng's eyes glowed even more.

"This flying skateboard is equipped with an anti-gravity device. When the time comes, I will give you a design drawing. You can mass-produce various types of anti-gravity devices. Then, you can modify various types of anti-gravity devices. All kinds of vehicles, so that you can bypass those roads and transport them secretly." Zhou Sen flew two laps before landing and sitting on the sofa.

"I know who you are..." Tang Xue looked at Zhou Sen with surprise.

"I..."

"Wang Wang..."

Just when Zhou Sen was about to speak, suddenly, Howling Celestial Dog came from outside There was a violent roar and rolling sound, and it seemed that Howling Celestial Dog had suffered.

Someone!

"peng!"

Zhou Sen has not had time to react. Amidst the loud noise of Heaven-shaking, Earth-shattering cry, a majestic and strange force actually turned the whole building The walls and roof of the wood house were swept in the air, but the furniture in the living room was completely motionless. Then, the huge roof was disintegrated in the air, and then, crushed to powder by an invisible force, the powder was blown into the sky by a gust of wind. Sweeping in the air, grandiose is like a long dragon flying in the air, magnificent.

What a ferocious power!

Zhou Sen's inner shock was beyond addictive. He did not expect that there would be such a tyrannical character on this planet.

A middle-aged man in a white robe stands in the yard with his hands in his hands. He is extraordinary. Howling Celestial Dog barks at him in the distance. Judging from the embarrassed appearance of its covered in dirt, it It should have been a disadvantage just now.

"West Asia War God!" Tang Xue said with a trembling lovable body.

"War God of the West Asian Empire?"

"Yes."

"Then there is only war!" Zhou Sen slowly stood up and pulled out After Tang Dao, a raging fighting intent exuded all over his body.

"You are not his opponent." Tang Xue's voice was trembling, which is evident in her fear of the War God in West Asia.

"the one to emerge victorious, I don’t know yet!"

Zhou Sen was aroused fiercely, with a smirk at the corner of his mouth, carrying a Tang knife, never without walls and roof In the living room, the step by step walked out of the yard. Just when Zhou Sen left, the flying skateboard summon from top secret entered the mecha button. Because of the atmosphere with swords drawn and bows bent, no one noticed the flying skateboard. Disappear out of thin air.

"Huh!"

Not good!

An extremely dangerous breath permeated.

Just after Zhou Sen and Tang Changfeng passed by, Tang Changfeng suddenly made a move.

Unfortunately, because the distance is too close, even with the bravery of Zhou Sen, it is impossible to avoid the sneak attack from behind. In fact, Zhou Sen does not have a dike Tang Changfeng at all.

"peng!"

A powerful force slammed Zhou Sen into the air, and then fell heavily to the ground motionless. From start to finish, the Western Asia Empire War God is completely motionless, and the white robe on his body is windless and automatic, giving people the illusion that they are flying at any time.

"Chang Feng, you are crazy!" Tang Xue roared sharply.

"Sister, I'm not crazy!"

"You...you...you actually betrayed us..." Tang Xue's eyes were red and her face was pale, and she was incredulous. Shaking his head.

"Sister, I'm sorry, awakened is too important to us." Tang Changfeng said with a smile on his face.

"Are you sure he is awakened?" Tang Xue looked at Zhou Sen who was motionless on the ground in despair. She knew that Zong Sect's last ray of hope was shattered.

"He meets all the characteristics of awakened, I think, you already know his identity." Tang Changfeng said with a smile triumphantly.

"Changfeng, you disappointed me so much...Changfeng...I don't have your younger brother...no..."

Tang Xue said with a desperate look While shaking her head, she suddenly pulled out the gun and aimed it at her temple without warning, but when she pulled the trigger, the expression on her face was frozen, because her fingers had lost consciousness. No, not just the fingers, her whole body is unconscious.

"Sister, you can't die yet. The emperor has seen your picture and never forgets you." Tang Changfeng hehe said with a smile.