Chapter 835 Smooth electromagnetic research work
Chapter 838: Smooth electromagnetic research work
Meetings within the aerospace field are still being held, and discussions on the lunar orbital mass projector are ongoing.
In the conference room, in addition to questions and suggestions on various details from experts and scholars in various fields, the most common questions were probably about why the country suddenly started such a 'science fiction' project, and who came up with this technology.
Not surprisingly, a young figure appeared in everyone's mind, and there was deep envy in their minds.
For everyone present, even the academician-level bosses, there is no one who does not envy that person.
Not even 30 years old, he is already at the pinnacle of academic circles.
With the title of academician of both academies and double winner of Fields Medal and Nobel Prize, he has reached the pinnacle in terms of reputation. He can be said to be the first and unprecedented person in history.
As for scientific research, there is no need to say more.
Perhaps most people in academia envy him for having several hundred-billion-dollar projects at his disposal, but those who know the inside story are even more envious because all of his research is always discussed separately among high-level officials.
It does not need to pass the review of the Science and Technology Commission, nor does it need funds managed by the Natural Science Foundation of China.
What others see as a super job, in his hands is just a matter of talking to the boss.
Just like this lunar orbital mass projector, this kind of project that even seems to be extremely science fiction in the aerospace industry, a super project costing hundreds of billions, is just the result of one person and one letter.
Of course, most scholars and researchers are just envious.
In other words, even if you are envious, you can't envy this kind of thing. You can only treat it as a 'myth' in your heart.
After all, any of the technologies and achievements that Xu Chuan has accomplished would take others a lifetime to study, and they would not even be able to complete them.
Like controllable nuclear fusion technology.
Just five years ago, it was dubbed the ‘Forever Fifty Years’ by academics. At that time, if anyone had said that controllable nuclear fusion reactors would light up the entire land of China in five years, everyone would have thought that he must be crazy.
But now, this story, which can be said to be a fantasy, has actually happened on this red land.
If he can reach this point, no matter which country he is placed in, I am afraid that matters related to him will only be handled on a special basis.
While the space agency's seminar on the Lunar Orbital Mass Projector + Lunar Orbital Space Station was going on, the initiator of this project locked himself in a villa at the foot of Purple Mountain.
Gao Hongming acted very quickly. After Xu Chuan asked for the experimental data of the electromagnetic railgun project, it took only two days to obtain the complete experimental data from the military and research institutions and units with related experiments.
Sitting in the study, Xu Chuan held a bag of yogurt in his mouth and tapped on the keyboard with his hands.
It is extremely difficult to establish a mathematical control model for the magnetic field inside the electromagnetic railgun.
Among other things, the analysis and calculation of three-dimensional elliptical electromagnetic fields and high-dimensional large-scale backscattering problems are world-famous mathematical problems.
This problem has important scientific and industrial applications, including the determination of PDE coefficients, initial value reconstruction, estimation of field source functions, testing of interfaces or boundary conditions, etc., which all require the solution of ill-posed nonlinear operator equations. It can be said that almost all Derived from research on it.
More importantly, it also involves effects such as reflection, eddy current, and diffusion of electromagnetic fields, which leads to an even higher level of complexity.
It is no exaggeration to say that the complexity of this problem can be compared with some T1 level mathematical conjectures.
Of course, complexity is complexity, not difficulty. There are still areas between the two.
Especially for Xu Chuan, this is not the first time to deal with such a highly complex problem.
After all, he also solved the millennium problem that was so complicated as the NS equation.
He peels off the cocoon, finds the thread that solves the problem, and then cleans it all the way, solving the problems in front of him one by one. This is what he does.
It sounds simple, but it is extremely difficult to find the most critical thread from a ball of thread that has been played with by a cat for countless days.
What's more, none of the difficulties you may encounter in the process of peeling off the cocoon are not so easy to solve.
Villa, in the study.
Xu Chuan is communicating with Xiaoling, an AI academic assistant.
Like other mathematicians who solve difficult problems, when faced with an extremely complex problem, the first thing he does is to search, collect and read various related papers and literature.
However, compared to the time before when he had to do it himself or ask a student assistant to help him, which took a lot of time to collect this information, the speed at which he can collect this information is much faster now.
You only need to lock in a detailed scope and classification, tell the AI academic assistant Xiaoling the required paper direction and literature field, and it will be able to handle this in a very short time.
Although the paper information collected by Xiaoling still needs to be reviewed by Xu Chuan himself, compared with the previous screening of massive papers by himself, this can already greatly save his preliminary preparation work and time.
After spending two days going through the thesis materials collected by Xiao Ling, Xu Chuan sat at his desk and took out a stack of manuscript paper from the drawer and spread it flat on the mahogany desk.
His eyes fell on the tip of the pen he was holding. After thinking for a while, he wrote the first mathematical task on the manuscript paper.
[(+k)u=0, in Dc, u=u^s+u^i, lim|x|→∞|x|^(n1)/2·(u^s/|x|iku^s ).】
This is the Helmholtz equation, and it is also one of the tools commonly used in mathematics to solve electromagnetic field scattering problems.
In layman's terms, if a problem involves the inverse problem of a partial differential equation (PDE).
Then this type of problem generally has the following form: given a PDE and some information about the equation solution u (based on practical application considerations, this information should be easier to obtain through measurement, such as boundary values or asymptotic behavior at infinity, etc. < br>
This is then used to invert some unknown information in the PDE, such as coefficients, domain, and even the model itself. As for the backscattering problem, it is generally assumed that the wave cannot penetrate the scatterer, that is, the scattered wave field only exists outside the scatterer.
But obviously, this kind of 'limited' calculation method is not what Xu Chuan needs.
For electromagnetic railguns, various issues such as internal magnetic field reflection and derivation are much more complicated than this.
In the study, the soft light illuminated the manuscript paper. While thinking, Xu Chuan wrote on the paper and said to himself:
".Give appropriate boundary conditions on the boundary D of the scatterer. If the scatterer is acoustically soft, you can consider u|D=0; and when the scatterer is sound-hard, we have
uν|D=0. ”
"But on top of this, the so-called impedance boundary condition needs to be considered, that is, (u/v+λu)·|D=0, λ∈C, Imλ>0"
"Then the scattering field at infinite ν distance has the following asymptotic expression: u^s(x)=e^ik|x|/|x^(n1)/2{u∞(x)+O(1/| x|)."
Looking at the manuscript paper under his pen, Xu Chuan's eyes showed a hint of joy.
According to his experience, before solving a complex problem, finding the entrance to the complex problem is the most effective and fastest way.
And as long as he found this opening, at least he would be able to see how to go next.
Regarding the magnetic field data problem of the electromagnetic railgun, he has successfully found the thread.
For Xu Chuan, it was only a year ago that he devoted himself wholeheartedly to theoretical research in mathematics.
After the weak Riemann Hypothesis was proved, he began to do more research in the fields of aerospace and physics.
However, for him, the familiar feeling of immersing himself in mathematics research work is not unfamiliar.
Especially in the fields he is interested in, every piece of additional knowledge acquired is like a dose of dopamine, bringing him satisfaction and happiness.
Especially when all his attention was focused on the black mathematical symbols on the white manuscript paper, it seemed as if the whole world had disappeared, leaving only the Arabic numerals and ancient Greek symbols in front of him.
The pen slides smoothly across the paper, leaving wonderful characters one after another, as if every stroke is a poem, and every word is a bright star, lighting up the whole world.
Late at night, a gentle lamp lights up in the quiet study, and the Purple Mountain outside the window seems to be sleeping. Occasionally, there are some rustling sounds, just like love words in a dream.
Staring at the manuscript paper on the desk, Xu Chuan's eyes were bright and he muttered softly:
".The first unique result can be obtained with the help of the spectral theory of the Laplace operator: the far field generated by infinitely many plane waves can uniquely determine an acoustically soft scatterer."
"Using the singular source field method, we can solve the problem that the far field generated by infinite plane waves can uniquely determine an acoustic hard scatterer."
"Then if the incident wave is a time-harmonic electromagnetic wave, the corresponding PDE model is a time-harmonic Maxwell equation. That is"
"."
For Xu Chuan, he has to consider not only the analysis and calculation problems of mathematically solving the three-dimensional elliptical electromagnetic field and high-dimensional large-scale backscattering problems, but also the mathematical model part.
In the field of electromagnetic field applied research, based on electromagnetic field theory and integrating new achievements in numerical calculation methods and computer software technology, a new branch of disciplines called electromagnetic field numerical calculation has been derived.
Numerical integration method is one of the basic contents in the application of numerical calculation methods. It not only lays the foundation for numerical quadrature of various types of integral expressions.
And with the increasing development of numerical calculation methods, it has become an indispensable component in the construction of various numerical methods.
However, for the analysis and calculation problems of three-dimensional elliptical electromagnetic fields and high-dimensional large-scale backscattering problems, due to the lack of compactness conditions caused by critical nonlinear terms, it is difficult to solve the problem through trapezoidal quadrature method, Simpson quadrature method, Gaussian quadrature method, etc. Product method and elliptic integral method are used to solve this problem.
But for Xu Chuan, it is not too difficult to creatively complete a new method for the lack of compactness conditions caused by critical nonlinear terms.
The only thing that needs to be considered is to combine computer software technology with anisotropic electromagnetic field numerical calculations, and use the computer's fast calculation speed and high accuracy to improve the speed and accuracy of anisotropic electromagnetic field numerical calculations.
The numerical calculation of rectangular long direct current-carrying conductors is realized through the direct integration method of field source discretization, and these numerical calculation methods are compared.
According to the running results of the analytical solution and numerical solution calculation program for the magnetic field of long direct current-carrying wires, it can be seen that the numerical solution and the analytical solution are very close and can meet the general requirements of electromagnetic field engineering.
Although this may not completely solve the problem, at least it can solve part of the problem!
Thinking of this, Xu Chuan pushed aside the full draft paper and wrote a new line of calculations on a piece of white paper.
【×E^sikH^s=0，×H^s+ikE^s=0】
Looking at the mathematical formulas on the manuscript paper, a smile gradually appeared on Xu Chuan's lips.
It seemed that he was going to spend a few days studying this issue in seclusion.
After stretching and yawning, Xu Chuan picked up his phone from the table, sent a text message to Zheng Hai, telling him that he needed to study some math problems, then stood up and walked towards the bathroom.
Although at the beginning, he did not expect to find the answer to this question in just a few days.
But unexpectedly, the analysis and calculation of three-dimensional elliptical electromagnetic fields and high-dimensional large-scale backscattering problems have been progressing quite smoothly.
In just two days, he had successfully found an entry point to this problem, and even completed preliminary simulation calculations on various issues such as magnetic field reflection and derivation in stages.
The process went so smoothly that Xu Chuan himself couldn't believe it.
As for now.
He was going to take a shower and get some sleep!
Wait until you get up tomorrow to start formally solving this problem.