Chapter 313

Fly?

Who doesn't want to fly?

Since ancient times, humanity's yearning for the sky has always been strong, and due to religious beliefs, they thought the sky was where gods reside. However, limited by ancient technological backwardness, flight was definitely impossible to achieve.

Countless people have tried to fly up to the heavens.

Yet all ended in failure.

So Liu Zheng's words instantly excited the three people.

"Young master... can this thing fly up to the sky?"

"Can it take flight?"

"Impossible? This..."

Although we know our young master is formidable, but that's flying up to the sky! In history, how many capable people couldn't do it—can Liu Zheng do it?

Liu Zheng chuckled.

He currently can't actually build an airplane, rocket, or flying vehicle, but being deeply influenced by later technology, constructing a glider is no problem for him.

This is something that suddenly popped into his mind these past few days while he was eating melons, watching shows, and fishing.

Why?

Very simple—it's aimed at the Xiongnu!

Liu Zheng pondered for a long time: why were ancient Xiongnu soldiers so difficult to deal with? Because their mobility was too strong. They could advance or retreat, making them very troublesome.

So what method is there to deal with the Xiongnu?

In history, there are actually records. The Book of Han mentions that back then, Wang Mang recruited extraordinary people from the populace, researched wings made from bird language, with feathers attached to head and body, feet pushing off the ground to truly fly hundreds of steps before landing—this should be the precursor to wingsuit flying.

And at that time, Wang Mang was precisely aiming to attack the Xiongnu!

Of course, regarding flight, in the early Ming Dynasty, there was a person named Tao Chengdao who held two kites, sat on a snake-shaped flying cart bound with forty-seven rockets, and used the rockets' reaction force to fly toward the sky—unfortunately he crashed, which is the story of "Wanhu Feitian."

While admiring these pioneers, Liu Zheng naturally wouldn't risk himself...

What he wants to build is a glider!

This is what he's been tinkering with these past few days.

A glider is the only way for him to achieve flight in this era. The main structure of a glider consists of a triangular frame, control frame, mast, tension wires, and umbrella cloth.

The triangular frame is composed of a keel, crossbeam, and two leading edge beams combined, establishing the planar shape and area of the umbrella wing.

The early triangular frame was on a plane, with the keel as long as the leading edge; later it gradually developed, the apex angle increasing, the keel relatively shrinking and becoming curved.

Since Liu Zheng has scientific knowledge, he naturally went straight for the most perfect design! He intends to control the glider's weight between ten and thirty kilograms, with the center of gravity slightly forward; of course, he still needs multiple test flights to determine the most suitable size and angle.

Near the tip of the leading edge, he also fixed an outer wash strut, whose function is one: to prevent the wing from simultaneously stalling; two: to automatically improve during a dive.

The control frame is also an equilateral triangular frame made of three rods, fixed below the keel and crossbeam, used for the pilot to operate direction. Nowadays, generally two wheels are still installed on the lower rod of the control frame.

The mast is fixed above the keel, used to support all landing tension wires, preventing the wing from bending under overload.

Tension wires: the tension wires on the upper surface of the umbrella wing are called landing tension wires, connected from the main mast to the apex, leading edge, and keel; their function is for landing or bearing the wing's weight on the ground.

The tension wires on the upper surface of the umbrella wing are called lift tension wires, connected from both ends of the control frame to the apex, leading edge, and keel; their function is to bear tension during flight; on the upper surface of the umbrella wing there is also a type called anti-camber tension wire, connected from the main mast to the rib of the umbrella cloth; its function is to give the airfoil a slight anti-camber, ensuring the glider can recover from a dive.

Umbrella cloth: the skin of the glider, sewn onto the triangular frame, and on both wings there are also sewn long pockets of a certain length, into which ribs are inserted to maintain wing shape.

Of course...

Later Liu Zheng will also make some flight equipment for pilots, to protect their safety.

But for now, this glider is still in the testing phase; those are matters for later.

"Young master, this this this, can this thing fly?"

Jiang Xuan was extremely excited.

Liu Zheng wore a mischievous smile: "Just try it and you'll know?"

Soon.

He then summoned a few soldiers, lifted the just-built glider onto a horse carriage, and drove to the suburbs. Jiang Xuan, Qin Zhangfeng, and Pei Qianyun—how excited they were needs no mention.

Of course.

Liu Zheng felt they wouldn't be laughing for long.

Although Liangzhou doesn't have as much wind as the Xiongnu grasslands, in winter the winter wind blowing on the face is still painfully cold.

Several people found a flat area not far from a hill; Liu Zheng surveyed the terrain, thought it suitable, and nodded.

The hills here are mostly not high nor low, just right for gliding; based on his grasp of his own mass, even if it overturned... it probably wouldn't cause any life-threatening issues.

For a triangular wing to fly, it must generate upward force. And this upward force is lift. A triangular wing generates lift by having a specific cross-sectional shape on the wing surface, causing air flowing over the upper and lower wing surfaces to have different flow speeds, thus creating a pressure difference that produces lift.

For a glider to sustain flight, the basic rule is to seek rising air currents and fly into them. Rising air currents have various causes; the most common are ridge airflow and thermal airflow.

When horizontal wind hits an obstacle, it is forced upward—this is ridge airflow.

When a patch of ground (or water surface) is heated by the sun and conducts heat to the nearby air, the hot air rises, forming thermal airflow.

Generally, ridge airflow distributes in bands along mountain ridges, with pilots shuttling back and forth within it; whereas thermal airflow originates from a point on the ground, rising in columnar or thermal bubble form, with pilots circling upward within that area.

This is also why Liu Zheng chose the glider to plot against the Xiongnu grasslands.

Because the grasslands are not lacking in ridges!

The unique Xiongnu grassland is even more suitable for glider flight!

Imagine if the glider were truly successfully developed—then the Yinzhou army could achieve a thousand miles a day, and the Xiongnu's mobility advantage would instantly vanish!

Not only can it meet combat needs, but it can also achieve even stronger reconnaissance effects!

"Ah? Young master, just take off from flat ground?"

The three people were a bit puzzled.

They still thought the first attempt should be jumping down from a height...

Liu Zheng rolled his eyes: I'm telling you to fly up, not to act as a parachute.

"Of course. Who goes first?"

"Me me me!"

Jiang Xuan was naturally the first, which made Qin Zhangfeng and Pei Qianyun roll their eyes in unison.

Afterward, Liu Zheng taught Jiang Xuan how to grip, and Liu Zheng chose the Vine-style grip. Because the Vine-style grip offers strong control over the angle of ascent, it is advantageous for adjusting the pitch during takeoff according to various takeoff conditions.

Jiang Xuan quickly mastered it, excitedly asking: "Can it really take off? Really?"

"Remember the movements I just taught you—I'll tell you when to run, and you run!"

Liu Zheng chuckled.

The other two watched Jiang Xuan enviously. If he really takes off, wouldn't he be the first person to fly?

At that moment, a breeze picked up.

Liu Zheng shouted: "Run!"

Jiang Xuan hoisted the Glider and ran straight into the wind.

Everyone stared, wide-eyed.

Can it really take off?