Chapter One Hundred and Five: The Model-Back Before the College Entrance Exam, I Became a Sensation in the Science Community(Flowing waters fill the goblet.)

“Fine, then let’s meet by phone at the appointed time,” Li Yisheng nodded. Wu Tong was not a three-year-old child; they were only worried about her safety and couldn’t follow too closely, lest she feel constrained and become rebellious.

The conference hall was still reasonably secure. Wu Tong was not a capricious girl—she would not wander outside, and she kept her word. He could trust her.

“If any problem comes up, never jump into a fight with anyone. Contact us immediately,” Li Yisheng repeated as they parted. “Keep our phones switched on.”

The venue required silence, but that didn’t stop them from setting their ringtones to vibration, easy to feel in the palm. Their most important task at this meeting was simply to keep Wu Tong safe.

“Got it,” Wu Tong said with an OK gesture, and headed for her first target: the session on partial differential equations. Fluid mechanics—if she was working in dynamics, PDE was the essential backbone.

“Existence and uniqueness of solutions, extendability, and dependence on initial conditions. Extending further to linear equations...”
The session on dynamical systems and ordinary differential equations was presented by Professor Fu from the mainland.

Wu Tong slipped in quietly and took an unremarkable corner, listening intently. She took careful notes when something mattered, and occasionally jotted down sudden flashes of thought from mental collisions between ideas.

Though her mathematical foundation was among the best in the country, in dynamics, in the engine sector specifically, she was still an utter newcomer. Most of the material she found online was broad and shallow. After returning from Mount Tai, she had gathered more books and references through Kyoto University channels and international sources.

Her close reading made sense at the level of theory, but what she had seen and known felt too basic. She still felt like a castle in the air, never truly on the ground of the field. Still, when she saw the title of this track, she was curious enough to set aside time to attend.

“...According to the dynamic... transformation model...”

At the end of the presentation, Wu Tong lowered her head a little and felt suddenly awakened. Why was she forcing herself to make this hard a part of dynamics and then translate it back into a math problem? Why not just build the mathematical model? Mathematics was her real foundation now.

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She only needed a direction for optimization, not to build a new engine from nothing to something. From a mathematical model, she could compute and simulate better parameters—this was her strength.

It was absurd, she thought—an overreach in reverse, labor and time spent in the wrong place, trapped by fixed patterns of thinking.

Still, her study of dynamics had not been wasted. To reformulate a problem, one needed some groundwork. Her recent growth in fluid mechanics and dynamics was rapid, and her thoughts had already expanded from the engine alone to the whole neighboring field.

Several parameters flashed into her mind. Wu Tong bent over her notebook and began to calculate in an unbroken hand.

Take the longitudinal axis as horizontal. Let drag be X. Maximum speed: Mach 2.5. Length: 18.90 meters. Wingspan: 13.56 meters. Height: 5.08 meters. Fuselage area: 78.04...
Impact force for a rectangular cross-section: ... medium sweep angle; the computed inner inclination angle of the center body is 35 degrees... synchronized lift-to-drag ratio...

From the partial parameters she had already seen, Wu Tong began to turn the problem around, converting it into mathematical models and calculating toward idealized values. Because the issue involved sensitive details, she used aliases and special symbols for many terms, and the elaborate chain of computations became a cipher only she could read.

A Western student who had come to learn under a professor happened to glance at a corner of her insight notes. He abruptly recoiled and pulled his gaze away. He couldn’t understand it. Where did this prodigy come from? Were all East Asian mathematicians this formidable?

Every East Asian student she happened to meet seemed so fierce. What state, then, was Wu Tong in—already making waves on the international stage? It was no mystery; that year her rise was nothing short of sweeping and overpowering.

The session ended. Wu Tong closed her notebook and followed the crowd out, then reunited with Li Yisheng at the entrance and returned to her hotel room.

This was already the second afternoon since the opening ceremony. At the last talk of the day, Wu Tong had gained some useful ideas.

After dinner, she told Li Laoshi that she would be preparing tomorrow afternoon’s presentation and tidying up what she had gathered over the past few days. She said she wouldn’t go out the next noon, so no need to wait for her.

Back in her room, like a child who has found a new toy, she resumed her calculations with fresh interest, filling in the gaps of the rough model she had started earlier that afternoon.

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In the one place where she was absolutely alone, Wu Tong stopped concealing herself. As she computed, she even picked up a ruler and began sketching. A once-blurry aircraft outline gradually took shape under her hand, and the numbers she derived were methodically marked in their proper positions.

The F-22 Raptor, one of the most advanced fighters of modern times, achieved formal operational capability in 2007. Many countries had spent nights and days on guard against its sudden beyond-visual-range appearance—its “dimensionality-reducing” strike, its domineering grip on air superiority. It was also the machine many Chinese researchers had labored over day and night, pouring heart and effort into catching up and surpassing.

Wu Tong’s impressions and data about it had come from a casual pass through memories of a future she had glimpsed; they had gathered dust in her mind before. In today’s conference, she was suddenly stirred, and her mind, by instinct, widened into associations that awakened that trace.

She began, from what she had just learned, to approach it through fluid mechanics and aerodynamics. From the scattered figures recovered from memory, she converted them into a mathematical model, and with her uncompromising spatial orientation and inferential power, started reverse-engineering the shape data.

Some values might not match the precise originals she lacked, yet these were the optimal figures calculated from her models built through mechanics and dynamics. If they differed from the official data, Wu Tong trusted her own numbers would still be the better choice. If the actual aircraft had not achieved them, perhaps materials and manufacturing conditions had not yet reached those theoretical optima.

At that moment she did not yet fully realize what she was doing or defining herself as; she only happened to seize the opportunity for some validating deductive calculations.

At 1:00 PM on August 23, a complete fighter sketch emerged at Wu Tong’s pen tip.

A ridged nose, sharp leading-edge canards, fuselage and wings, twin-vector nozzles... A full fuselage layout appeared on the sheet, detailed figures crowded across it, each arrowed annotation in place.

Beyond the rough aircraft shape, Wu Tong further calculated the thrust-to-weight ratio of the engine, then from a materials perspective analyzed maximum fuselage stress tolerance, density, and mass, asking which materials now came closest under the strict limit of structural weight. With limited data in hand, she could only infer only a rough approximation.

Titanium-aluminum alloy?

(End of this chapter)