I Am the President of the University

"I'm the president of the university(

(Note: The mathematical model competition involved in the novel is not taken from this year, but from last year's topic. There are more information about last year on the Internet, so we will take the 2019 digital model competition)

To solve a problem, you must first analyze it based on the problem.

There are three questions in question a.

There are also 2 small questions in question one and question three. The summary is:

(1) When the pressure in the high-pressure oil pipe is stable at 100MPa, how to set the opening time of the check valve each time? The pressure in the high-pressure tubing increases from 100 MPa to 150 MPa and stabilizes at 150 MPa after about 2 s, 5 s, and 10 s adjustment processes. How to adjust the opening time of the one-way valve?

(2) Determine the angular velocity of the cam under the number of injector operations, the size of the high-pressure oil pipe and the initial pressure given in question 1, so that the pressure in the high-pressure oil pipe is as stable as possible at about 100MPa.

(3) On the basis of Question 2, add another fuel injection nozzle. Each nozzle has the same fuel injection pattern. How should fuel injection and fuel supply strategies be adjusted? Please give a control plan for the high-pressure oil pump and pressure reducing valve.

【Question one:

The first small question: The problem defines a constant oil outlet method, and the defined oil inlet method is only related to the system pressure and the opening time of the check valve each time. Secondly...

The second small question: The problem requires us to adjust the system pressure from 100MPa to 150MPa and stabilize it at different times. This first requires us to...]

[Question 2: This question redefines the oil inlet and outlet methods. At this time, the oil inlet method will be related to the angular velocity of the cam. This requires us to re-describe the oil inlet and outlet methods on the basis of Question 1, and set the decision variables... 】

[Question Three:

The first small question: This question is based on the second question. A new fuel injector is added to the system, so the fuel delivery method will be changed. Is the fuel injection time of the newly added fuel injector...

The second small question: On the basis of the previous one, a pressure relief valve is defined. Since the problem does not describe its working method accurately, we need to define the working method of the pressure relief valve...]

After the analysis of the problem is finished, then you can clarify the ideas for the problem, and then divide the work, solve the problem and model, find the literature, prepare the thesis template, and write the program.

"Zhang Lei, please go to CNKI to check some documents for me, and prepare a paper template."

Lu Zhou didn't lift his head and continued, "Old Zheng, you should familiarize yourself with the next topic first, and you can prepare to program after I build the model."

The two nodded and waited.

Just then, there was a knock on the door.

The three of them looked towards the door, and stood Chen Hao impressively.

With three cups of Starbucks in his hand, Chen Hao walked in with a smile.

"Students, how's it going, is the topic difficult?" Chen Hao put the coffee on the table and said with a smile: "Drink some coffee to refresh yourself. I also ordered Kaifeng dishes for you. I can arrive."

"Thank you, principal!" Zhang Lei stepped forward to distribute the coffee with a happy face.

However, Zheng Tianyu scratched his head embarrassedly and said, "Principal, this is too costly for you."

Now in this classroom, not only is there a three-tatami bed in the corner, but a box of barreled instant noodles, red bull and snacks are stacked on the side.

This preparation made the three people really warm.

I also made up my mind to get a good result.

"It's okay, the game is important, I'll look at the topic." Chen Hao said with a smile, sitting in a position where Zhang Lei let out, looking at the topic on the screen.

After reading it in a while, I also typed a bit in my heart.

During the competition, it is not possible to discuss topics with instructors and outsiders, so Chen Hao could not help them.

Zheng Tianyu looked at Chen Hao curiously and asked, "Principal, do you think this question A is difficult?"

"It's okay, it's quite simple. But I can't teach you guys, come on, let me first look at student Lu Zhou's problem-solving ideas." Chen Hao finished speaking easily, and stood up behind Lu Zhou.

Lu Zhou was waving a hand on the a4 paper, and there were more and more formulas on the blank paper. Calculating on the paper, whispering:

"Since the change in fuel pressure is proportional to the change in density, and the question gives the relationship between the proportional coefficient and the former, the fuel state equation can be obtained:

dPdρ=E(p)ρ, where P is the pressure and ρ is the density. "

After speaking, Lu Zhou looked up, looked at Zheng Tianyu beside him, and said, "Old Zheng, you can use the software to help me calculate p(ρ)."

"Ok." Zheng Tianyu just took a sip of coffee and quickly tapped the keyboard according to the data given by Lu Zhou.

[[Fitresult, gof]=createFit(p, K);

rhospan=[0.850.9];

p0=100;

[rho,p]=ode15s(@(rho,x)(fitresult.p1*x^6+...

...

figure;plot(rho,p);(\'fuel density rho\');(\'pressure p\')】

As for Chen Hao on the side, the two of them were too busy to care.

After all, time is tight, only 72 hours.

Chen Hao nodded as he looked at Lu Zhou's thoughts on solving the problem, somewhat relieved.

"Come on, do the questions well, and remember to take a break."

After the exhortation, Chen Hao left directly.

And because the topic of this year's Mathematical Contest in Modeling is too perverted, the Internet is directly fried!

On the journal websites such as CNKI and Wanfang, the top three most searched keywords are: airport taxi, concentric drum, high pressure oil pipe.

These three are the three questions of this year's mathematical modeling competition.

Zhihu also raised a hot search, "How to evaluate the 2020 Mathematical Modeling Competition?"

Discussions on the topic of digital simulation competition on Weibo are also getting hotter.

"The menstrual period is disordered half a month in advance~www.wuxiahere.com~ The chair in the computer room is blood-stained, and it's fine if it's done well, none of the key issues have been solved..."

"The carnival of science and engineering schools, the wailing of financial schools!"

"I can't understand question A, question B won't count, and question C has no data."

"I made up fluid mechanics, hydraulic transmission, and process control in one night, and looked at the problem again and still looked confused."

"From the opening of the question to the change of the question, and then from the change of the question to making up..."

Beijing, in the computer room of Peking University.

Although it is rumored that students from top universities like Tsinghua and Peking University do not like to participate in outside competitions and are more keen on intramural competitions, the first place in the national competition is still very attractive.

Especially when competing for special scholarships, the top academic bachelors in those prestigious schools have all their resumes and journal papers...

There are seven teams of 21 people in the computer room, and each team is rubbing shoulders and pointing at the Higher Education Club Cup.

The team member beside Lu Ziming asked, "Ziming, which question do we choose?"

"Choose question A." Lu Ziming said lightly, "Question A is the most difficult. We are ready to start. This time we must win the Higher Education Club Cup."

The three majors of the team are Mathematics + Physics + Letters. Facing the problem of high pressure tubing, there is no difficulty at all.

Their opponent is...

Lu Ziming looked around the classmates in the computer room, his eyes were sharp.

As long as you beat the classmates in the same computer room, as well as the top teams of Tongji, Nankai, Nanda, and Huake, the championship will be stable!

As for the other schools...sorry, they are not among the imaginary enemies.

ps: Ask for a recommendation ticket! It's more than 300 votes to break 10,000, please support! ! !

I checked the information in this chapter for more than 2 hours in the early morning, and I really vomited, but don't spray water... I quickly transitioned out, it was too difficult to write details.