In the afternoon, Zhuoyue followed Professor Ji to his laboratory.

This is a large experimental base. After passing the security inspection at the door, their car drove in.

Professor Ji said: "There are not only aerodynamic laboratories, but also kinematic laboratories, materials science laboratories, structural mechanics laboratories, aero engine laboratories and avionics systems laboratories, etc."

Zhuoyue looked out through the car window. The laboratory base was like a science and technology park, covering an area of ​​more than 5,000 acres, and there was a large artificial lake. Next to the artificial lake, there was a building that looked like an airplane, and square buildings like a factory building were placed in an orderly manner around.

The car stopped in the parking lot, and they walked to a building, passed Professor Ji's fingerprint verification before entering the laboratory.

There were many people coming and going in white coats. When they saw Professor Ji stop to say hello, then looked at Zhuoyue and Professor Yang curiously, and then left in a hurry. Everyone seemed to be very busy and walked quickly.

After twists and turns, you can enter a room with an area of ​​more than 100 square meters.

I was surprised to see the equipment inside.

I saw a water tank of more than ten cubic meters near the wall of the house. There is a water inlet above the water tank and a sewer outlet is connected to the lower part.

There is a laser sheet above and directly in front of the water tank.

There is a dozen square open space on the left side of the water tank. There is a round hole with a diameter of one meter on the wall of the open space. There is a large fan in the round hole. There is a large fan opposite the large fan. There is a laser sheet above and on the left side of the fan.

Directly in front of them, two meters away from the water tank, that is, in the middle of the room, there are a row of machines, three computers in the middle, placed obliquely, and a holographic projector to the right of the computer and a printer to the left of the computer.

There are two square, skull-sized synchronizers between this row of machines and the water tank, placed on the ground.

Zhuoyue walked to the row of machines and looked at these machines in surprise. Women like bags, lipsticks and high heels, and men like cars and watches.

But excellence is a unique love for scientific research machines!

After a long time, Zhuoyue turned his head to look at Professor Ji on the side, pointed to the holographic projector and said, "Professor Ji, can this be done for three-dimensional technology experiments?"

"Of course," Professor Ji smiled and said: "The advancement of modern technology has allowed us to abandon the original experimental methods. Three-dimensional technology allows us to intuitively see the holographic panoramic renderings of the experiment."

"At the same time, because of the emergence of three-dimensional technology, we have many more experimental technologies. The experimental technology in turbulence is the high-spatial-time resolution three-dimensional velocity field measurement technology."

Looking at Zhuoyue who was eager to try, Professor Ji smiled and said, "Do you want to try it?"

Zhuoyue asked excitedly: "Is that OK?"

The best experiment he has done in turbulence before is to measure compressible turbulence. A relatively old technique is to use optical analysis to use the average particle displacement obtained by the Young's interference bar to obtain the velocity field.

This technology appeared in the 1980s, and it was almost eliminated in many places.

"Of course, you can do it yourself." Professor Ji took a step forward, walked to Zhuoyue's side, and said, "I'll explain the operation steps to you."

After a long time, Zhuoyue became familiar with the buttons and operating steps on the machine.

"Did you remember? If you remember, you can try it."

Zhuoyue suppressed his nervous and excited mood and said, "Remember."

"Then let's start!"

Zhuoyue breathes out and presses the start button.

In an instant, with a buzzing sound, the computer started, the synchronizer was running, the holographic projector sounded, and the laser sheet lighted up.

Afterwards, he pressed the water to release the water. In an instant, a rotating water column fell from the water tank. He turned his head and looked, a 1:10-simulated water column formed by laser appeared on the holographic projector.

Professor Ji said: "Now start choosing the mobile display!"

Excellent first choose streamline!

There are three types of flow display, namely flow lines, traces and chromosomes. The three types of display have different effects.

Soon, a curve appeared on the computer screen, which was the curve of the velocity direction of all parts of the water flowing.

Professor Yang came over and the three of them looked at the computer screen together.

Professor Ji said: "Turn into a trace!"

Press the trace button and the mouse randomly clicks on a certain water flow point in the water flow, and a curve with different amplitudes appears on the screen.

This is a curve formed by different time periods of the velocity direction of the water flow point he selected.

"The chromosome at the end!"

A chromosome is also called a vein line. A chromosome is a fixed point in the water flow and a microcolumn of fluid flowing through this point.

"Okay, turn it off!"

Purely press the close button, all machines stop running, and the water in the water tank flows out from the outlet.

Professor Ji looked at Zhuoyue and asked with a smile: "How do you feel?"

Zhuoyue smiled and said, "It's much better than the machine experiments in school."

"Haha... the equipment in the school is old, so I can just do it for you students, but the equipment here is the latest. Those Europeans are not short of money, so I asked them to get me this set of equipment."

"Although it's not the top, it's also very high-quality."

“Do you want to try more mobile displays?”

Zhuoyue's eyes lit up and he asked, "There are other flow displays?"

"Of course, I have not only chromosomes, but also hydrogen bubbles, suspended particles, free surfaces and flakes of light."

"This is just water flow, I have a low-speed air flow display."

"There are smoke wires, silk wires and fluorescent microfilaments, respectively."

Zhuoyue was excited when he heard it. He had only seen most of these experimental methods on PPT, and he had never even seen them on PPT, and had only heard of them.

Professor Yang glanced at Professor Ji, "Isn't there a laboratory? Isn't it lucky to be behind this laboratory? It depends on his intentions."

Professor Ji asked with a smile: "Which type do you want to experiment?"

“Suspended Particle Flow Show!”

The flow of suspended particles is the most advanced experimental method. I heard that the experiments performed are very beautiful, and the water sprayed out is like a combination of countless fireflies.

"Let's go to the next room!"

The equipment in the next room is similar to the equipment in the previous room, except that there is no fan and only a water tank.

The water in the water tank does not flow down from above. There is an iron pipe about ten centimeters in diameter on the right side of the tank.

The room was very dark, with only three lights next to the computer. The lights were only facing the computer, and the water tank was very dark.

Professor Ji said: "I'll come here, you can watch from the side."

"Yeah!" Zhuo Yue nodded.

Professor Ji explained while operating.

"The flow of suspended particles is shown by mixing some visible solid particles or oil droplets into the water stream to understand the flow structure of the water stream from the motion state of the solid particles or oil droplets."

"The materials generally available are silver-white balls and oil droplets made of a mixture of polystyrene particles, aluminum powder, wax and rosin."

As he said that, he started the machine and pointed to a button and said, "The silver-white balls have been mixed long ago. This button puts these silver-white balls in the water."

After he pressed the button, he could only hear countless clicks and sounds continuously and densely, just like countless small iron balls rolling in the iron pipe.

After more than ten seconds, the sound gradually disappeared!

"This button is launch!"

After he pressed the launch button, a light green water flow spewed out in an instant, like a flame, and a gorgeous picture appeared.

Zhuoyue looked at this scene with a confused look.

Scientific research is not as boring as outsiders imagine. It has its beauty, but it cannot be seen or imagined by ordinary people.

Only scientific researchers can enjoy it during experiments.

A series of curves are displayed on the computer screen. The holographic projector simulates the picture in the water tank and the printer prints the curves in the computer.

After a long time, Professor Ji turned off the machine and withdrew his gaze with regret.

In the next few days, in the laboratory, they experimented with all the remaining flow displays.

Not only is there a flow display of water flow, but also an air flow display.

Professor Ji held dozens of papers covered with curves and particle images in his hand and said, "Let's calculate the results of the experiment!"

In the office of Professor Ji's laboratory!

The three of them sat down around a table, and all the experimental reports were spread out on the table.

Professor Ji said: "According to Reynolds' experiment, I know that the upper and lower critical flow velocity is laminar rheological turbulence, and the lower critical flow velocity is turbulent laminar flow."

"So, we can study the rules of turbulence, statistics and spectrum of turbulence pulsation."

"According to my research over the years, the velocity field of turbulence is an irregular function of time, space coordinates and experiments..."

“…”

【When ξ=0, =∫s??(k)exp(ik.ξ)dk    ?dk    ?dk    ?.】

"The spectrum s??(k) represents the distribution of pulsating kinetic energy in the wave number segment (k,kdk)."

Professor Ji threw down his pen and said, "This is my research over the years. Do you see what should you do next?"

Zhuoyue said: "Professor Ji, based on the experiments over the past few days, I have come up with a method, and you can see how it is."
To be continued...