Exclusive Memory Chapter 5 Part 7

 In the last few minutes before the bell was struck, we finally reached the Riverside Square. The square is facing the confluence of the north and south rivers, and a small part is suspended, so standing on the side with the railing and looking down to see the rushing river rushing eastward under your feet, you will suddenly feel that you are on a boat.

In the corner of the square, there is a huge bell tower, and many people are waiting to welcome the countdown to the New Year.

This time is the most violent period of fireworks, and the gorgeous fireworks rush into the air one by one, very dense. Even people dare not look up straight, lest the soot fall into the eyes.

When I saw the flying fireworks, I suddenly remembered the question I asked Peng Yu, "Teacher Mu."

"Huh?" When he answered me, his eyes still fell elsewhere.

"Airplanes fly into the sky according to that uncle's law, so..."

"Bernoulli," he said.

"So when the plane does the flipping action, the up and down direction of the wing is different, why doesn't it fall?"

I looked in the direction he was looking, and it turned out to be a little boy holding incense and lighting fireworks, and it seemed that he was very timid, and the line of fire did not ignite, so he turned his head and flew into his mother's arms, making the adults laugh.

"Why did you suddenly become interested in airplanes?" He lifted the corners of his mouth, asked with a smile, and moved his gaze to my face.

My face instantly turned red, and I coughed deliberately, and in order to hide my embarrassment, I hurriedly explained: "Because... Because I talked to Peng Yu about this last time, I think if I figure it out, I can show off in front of him next time and save the majesty of being a teacher.”

My gaze became more and more determined, and finally even I thought that it was because of Peng Yu that I was interested in airplanes. So as the saying goes, to convince the enemy, you must first believe yourself.

"Really?" He casually said, "You guys still talk about this?" 

"Well."

Uh -- that's a little deeper.

"You said that flip, we call it horizontal roll, is it a 360-degree rotation vertically?"

"Yes, yes, yes." I'm glad he understood what I meant.

"What you want to ask is, why doesn't the plane fall when it flies upside down? Flying upside down means the pilot with his feet up and his head down. ”

"Bingo, exactly." Those who know me, Teacher Mu also.

"Actually, actually, it's not that the reason why the plane can take off has many functions, not all of which can be explained by Bernoulli's law."

"What's the reason for that?"

"The shape of the airplane's wing can indeed provide a certain amount of lift when the airplane is flying normally, but the lift of modern wings mainly comes from the elevation angle, that is, the acute angle formed by the air flow blowing towards the wing." He pondered for a while, It seems to be thinking about how to explain it to me, an absolute layman, so that it is easy to understand. "I don't know if you have observed carefully. When the plane is flying upside down, the nose is not horizontal or diving, but it will be tilted upwards. If Experiment with a piece of paper at an angle, and you blow hard down on it, and it goes up."

He thought for a while and continued: "To put it simply... the principle is like flying a kite. The head must be lifted up, and there is naturally an air support. But it must be ensured that the head is tilted up at an appropriate angle. When the force is greater than the downward force generated by the shape of the wing in inverted flight, it can fly inverted."

When he talked about his profession, his eyes were always crystal clear and bright. I was a little distracted, and when I thought about what he explained, I seemed to understand it, but I didn't seem to fully understand it.

"Can all planes fly upside down?" I asked.

"Theoretically so."

"Theoretically? So what's the problem in practice?"

He said with a smile: "Because there is a troublesome thing. Generally, if the plane is turned upside down, the fuel tank will also be turned upside down. Maybe the fuel will be stopped, causing the engine to suddenly shut down."

"Then what to do?"

"For general military or aerobatic aircraft, the easiest way is to install an inverted fuel tank, which is enough to support the aircraft to fly inverted for about 30 seconds. "

As we spoke, bells rang suddenly behind us, and then people began counting down the last ten seconds of the new year in unison. I got up excitedly: "This is the most effective time to make a wish." Then I closed my eyes and folded my hands together, and after silently saying the wish in my heart, it was exactly three seconds before zero.

"3—"

"2--"

"1--"

I suddenly turned around and said loudly at the first time: "Happy New Year!"

At that moment, firecrackers were set off, the night sky was as bright as day, and the crowd was restless. Infected by this scene, I couldn't help but open my arms and wanted to hug him.

When the movement was in mid-air, I suddenly realized my overstepping, and my hands became stiff, neither closing nor continuing, very embarrassing.

But Mu Chenghe leaned his body forward slightly, then lowered down, and embraced me with his arms.

ery light, very light.

He seemed to just lightly touch my back with his fingers.

However, even so, through the thick clothes, this action still made my heart skip half a beat.

I touch his shoulder with my face and smell his scent.

In just one or two seconds, it made me feel as long as a century, even a little greedy.

He said: "Xue Tong, Happy New Year!" Then he let me go without a trace, his eyes were open and his face was upright.

My originally satisfied heart was filled with a little melancholy.

More than ten minutes after zero o'clock, the flow of people began to disperse one after another. Some went home; some went to supper and continued to the next round of entertainment.

So the traffic suddenly became congested.

Once the alcohol is gone, walking in the early morning of a winter night like this really feels very cold. The night wind was very strong, and my hair was covered, so it was blown up and down, and my cheeks hurt raw.

Mu Chenghe left me next to a small cigarette stand that was still open. The stall owner was a middle-aged aunt who lit an incandescent lamp and propped a big umbrella against the wall, just enough for me to shelter from the wind and cold.

Then, he walked to the intersection by himself against the wind , and helped me hail a taxi.

Helpless, there were not many cars, and he was very good-tempered. He managed to stop a car with someone at the same time, but when he saw that the other party was a lady, he gave it to her without saying a word.

Ten or twenty minutes later, the man returned without success, with a depressed expression on his face that she had never seen before.

"It's got to be the hardest thing in the world," he said.

Next Chapter ---->