Volume One, Chapter Seventeen: Enough Supplies

The truck slipped silently into the abandoned factory complex under the faint light before dawn.

Shen Qingyun nearly burst out of the vehicle, his graying hair whipping wildly in the cold wind. His faded work overalls were stained with grease. "Well? Did you get it?"

Du Yuze jumped down and handed over a small metal box.

Shen Qingyun grabbed it and opened the lid, his cloudy eyes fixed intently on the contents inside. He reached out with hands roughened by calluses and scars, carefully picked up a sealing ring, and held it close to his eyes. After a moment, he exhaled deeply and visibly relaxed. "It's genuine... good quality."

His joy was short-lived.

"Is that all?" came a hoarse voice from the workshop door. A man around fifty emerged, lean in build, wearing a greasy leather apron and carrying a large wrench. This was the factory’s finest mechanic, Li Guishou. "Twenty pieces? What’s that good for? Not even enough to fill the gaps between teeth!"

Shen Qingyun’s face fell. "Xiao Du, is that really it?"

"Old Jin only had these," Du Yuze replied.

"I told you, you can’t trust black market stuff!" Li Guishou slammed the wrench onto the workbench, the clang ringing sharply. "All this effort, and this is what we get? We can’t even perform one full ground test!"

Pang Qingquan got out of the cab, his legs still weak. Leaning against the door, he wanted to argue but found himself speechless. Last night’s ordeal still haunted him.

"It’s enough," Du Yuze said firmly.

"Enough?" Li Guishou sneered, scrutinizing Du Yuze as if he were a fool spouting nonsense. "Young man, do you know what you’re saying? The key to pneumatic modification is verification! We have to repeatedly test the wing’s vortex patterns at different angles to find the critical point! Twenty sealing rings could be scrapped in a single high-pressure run! Just once! Do you understand?"

"We don’t have the conditions to verify," Shen Qingyun sighed, deepening the lines on his face. "Forget repeated tests—we don’t even have a wind tunnel. The whole base has only that precious contraption in the research institute, and the queue extends into next year. Without a wind tunnel, all our modifications are just empty talk."

A sense of despair settled over them. Li Guishou paced irritably in the workshop; Pang Qingquan hung his head, while Shen Qingyun stared blankly at the metal box as though it were not a beacon of hope but a heavy-handed irony.

"We can build one ourselves."

Du Yuze’s words froze the air.

Li Guishou stopped mid-step, turned, and looked at him as if he were an alien. "What did you say? Build one ourselves? Build what? A wind tunnel? Do you know what that is? Hundreds of tons of special steel, ultra-precise control systems, a monster that could drain a small city’s electricity! And you want to tell me we can build one ourselves?"

"Not a wind tunnel," Du Yuze’s tone was steady. "A test platform that can simulate high-speed airflow."

He walked toward the corner of the workshop where a dismantled J-5 fighter lay in pieces. The nose section had been removed by a crane, exposing complex piping and structure inside.

"Lift the nose, suspend it in midair," Du Yuze instructed, pointing to the massive metal piece. "Clear twenty meters ahead."

"And then?" Shen Qingyun followed, sensing what Du Yuze was about to say but reluctant to believe it.

"Use that." Du Yuze pointed to a huge industrial blower at the far end of the workshop—the factory’s giant fan used to supply air to boilers. Its power was immense; when started, the whole workshop hummed.

Li Guishou was enraged. "Blow a fighter with a blower? Du Yuze! I don’t care who you are, but you can’t joke with our hard work! That’s madness! The airflow will tear you to pieces!"

"Unstable airflow means useless data," Shen Qingyun shook his head. Though he admired Du Yuze’s boldness, the idea was absurd. "What that blower produces is turbulence, not the high-speed laminar flow a plane encounters in flight."

"We can make it laminar," Du Yuze said.

"How? You gonna blow it with your mouth?" Li Guishou mocked bluntly.

Du Yuze ignored him and moved to a dusty control panel, quickly scanning the instruments and switches. His mind raced.

[System: Analyzing performance parameters of existing industrial blower, matching flow field characteristics needed for J-5 wing root at Mach 0.8.]

[System: Calculating... prerequisites required: precise angle of attack and sideslip angle.]

"Master Li," Du Yuze turned, "I need you to set the crane’s nose arm to 5.2 degrees pitch-up and 1.5 degrees yaw to the left."

"And why should I listen to you?" Li Guishou stiffened.

"Trust me," Du Yuze said simply.

Those two words made Pang Qingquan tremble. Those same words had saved them from utter despair in the scrapyard. He opened his mouth to urge Li Guishou, "Master Li… why not give it a try?"

Li Guishou glared at Pang Qingquan, then looked at Shen Qingyun.

Inside, Shen Qingyun battled with himself. Reason told him this was nonsense, but an inexplicable instinct—a gambler’s desperation—made him decide. "Old Li, listen to him. Anyway… it can’t get any worse."

Grumbling, Li Guishou climbed onto the crane’s control platform and started the machine. The heavy chains creaked as the massive J-5 nose was slowly lifted and held suspended at the strange angle Du Yuze specified.

"And then, genius?" Li Guishou poked his head out from above.

"Cotton thread and glue," Du Yuze said. "On the right wing’s surface, from leading edge to trailing edge, paste rows of cotton thread every five centimeters."

Even Shen Qingyun was baffled. What kind of crude method was this? This was something from the days when biplanes were tested decades ago.

Despite their doubts, they complied. Half an hour later, the wing was covered with cotton threads of varying lengths, looking both ridiculous and pitiful.

"Everyone, retreat behind the safety line," Du Yuze stood before the industrial blower’s controls. "Engineer Shen, get your pressure sensors ready."

Shen Qingyun retrieved a rudimentary device he made himself from his toolbox—a pressure gauge connected to a slender metal probe. He took a deep breath and moved to the wing’s side-rear position, as Du Yuze had just indicated.

"I’m about to start," Du Yuze’s hand hovered over the switch.

Li Guishou and Pang Qingquan hid behind a pile of steel, only their heads visible.

"Crazy, all of them are crazy," Li Guishou muttered under his breath.

Du Yuze flipped the switch.

The workshop was instantly engulfed by a deafening roar. The blower awoke like a beast, spewing furious airflow directly at the suspended nose.

The cotton threads on the wing whipped wildly, chaotically, like wild grass in a storm.

"See? I told you! It’s all chaos!" Li Guishou shouted, but his voice was mostly drowned by the noise.

Shen Qingyun’s heart sank. Just as he expected—utterly irregular.

"Power, seventy percent!" Du Yuze shouted at the control panel, turning a large dial.

The wind suddenly intensified!

A miracle happened.

At the moment the airflow crossed a certain threshold, the wildly flailing cotton threads seemed to be smoothed by an invisible hand, all neatly pressing back against the wing surface in smooth, flowing lines! They ceased their frantic dance and pointed steadily backward, clearly tracing the airflow direction.

"This… this is…" Shen Qingyun’s pressure gauge quivered violently.

"Look at the wing root near the leading edge!" Du Yuze’s voice rang out again.

Everyone looked where he indicated. At the junction of wing and fuselage, the cotton threads closest to the leading edge didn’t lie flat but began to spiral slowly and rhythmically—forming a small, stable vortex!

Shen Qingyun held his breath. Trembling, he carefully extended the sensor probe toward the vortex’s edge.

The pressure gauge needle jumped sharply, then steadied at a reading.

"My God…" Shen Qingyun murmured, "Pressure gradient… separation point… perfectly accurate! It matches the transonic vortex model I studied in textbooks!"

He suddenly looked up at the young man standing before the roaring wind and deafening noise, his figure tall and resolute.

"Increase power to eighty-five percent!" Du Yuze commanded again.

The wind’s howl sharpened.

The small vortex on the wing suddenly expanded and began moving along the leading edge toward the wingtip! The previously flattened cotton threads were successively drawn into the new vortex, forming a larger, clearer rotational pattern.

"The vortex… the vortex breakdown point is moving backward!" Shen Qingyun shouted excitedly, frantically recording data from the sensor. "Our modification works! It really delayed the shock wave formation!"

Li Guishou emerged from behind the steel pile, standing dumbfounded, mouth agape, speechless. A lifetime of mechanical work and trusting his own eyes and hands was shattered by what he now witnessed.

This was no mere blower. At this moment, it was a wind tunnel. A crude yet astonishingly precise wind tunnel.

Finally, Du Yuze shut off the power.

The roar faded, and the workshop fell into an eerie silence.

Pang Qingquan leaned against the wall, feeling as if he had just awoken from a dream.

Shen Qingyun cradled his precious sensor and the sheets covered with data, as if holding a rare treasure, muttering over and over, "It’s feasible… really feasible…"

Li Guishou slowly walked under the J-5’s wing, gently touched the wind-streaked cotton threads, then turned around and approached Du Yuze. He stared at the young man, younger than his own son, for a long while.

"How did you get that brain of yours?"