"What the hell is this plane?"

Tang Rui's eyes widened, looking at the screen a little confused.

He hadn't seen the plane.

But he's sure it's Eagle Sauce's latest supersonic stealth reconnaissance aircraft.

"This appearance is different from the revealed Goddess of Dawn."

The drone chased behind.

Using the optical system, the aerodynamic shape and body structure of the entire supersonic stealth reconnaissance plane were photographed.

Tang Rui looked at the three-dimensional model on the screen, and his brain was calculating rapidly.

"Integrated forging technology."

"Scramjet engine."

"Long fuselage and short wings."

According to the condition of the body, he thought about it for a long time, and suddenly thought of a verification machine for eagle sauce.

HTV-3X Black Swift.

It is said that this verification machine is a technical reserve and technical verification for the purpose of developing the SR-72.

In the outside world, this verification machine is not well-known, and compared with the Goddess of Dawn, it is far behind.

But who would have thought.

This thing has even begun to fly secretly.

"it!"

Just as Tang Rui was thinking, this dog thing actually began to speed up.

He glanced at the map.

The discovery has returned to domestic airspace.

No wonder you have to speed up, if you fly a little slower, it is easy to be knocked down.

Tang Rui also pushed the throttle valve, so that the drone chased after it closely.

But soon he found out.

The drone couldn't catch up.

Even if he has pushed the speed to the maximum, reaching Mach 4.2.

But compared with the supersonic stealth reconnaissance aircraft in front of him, which reached more than Mach 6, it is still too far behind.

Less than five minutes.

The reconnaissance plane completely disappeared from Tang Rui's sight.

Radar can't scan.

The optical system tracks and can only see a blurry point of light.

Tang Rui pulled down the throttle valve, exited the afterburner state, and let the drone enter the subsonic cruise state.

Very unpleasant.

It's not that he doesn't work hard.

The main thing is the engine.

Turbojet engines and scramjet engines are not on the same level.

The engine had to be upgraded.

Tang Rui has decided that when he comes back this time, he will strengthen the engine of the drone.

Three o'clock in the morning.

He fought hard and controlled the drone to land.

Run in front of the drone.

Look at the system panel.

The experience value of the drone has long been overflowing.

[Item: Perfect Recon Aircraft Drone +4]

[Experience: 87363/26000 (Upgradeable)]

[Enhancement: Airframe, Avionics, Engine, Energy]

[Feature: High-precision scanning]

[Source point: 5.64 (can be enhanced)]

Tang Rui didn't say a word, and directly clicked upgrade.

A flash of blue light flashed.

The drone upgrade is complete.

However, in this upgrade, the body of the drone has not changed much, but there is one more feature.

Strong stealth performance.

Tang Rui looked at the experience bar and found that he could continue to upgrade.

Click Upgrade.

Another blue glimmer flashed.

The drone upgrade is complete.

[Item: High-Performance Stealth Unmanned Reconnaissance Aircraft +6]

[Experience: 3363/?] (Non-upgradeable)】

[Enhancement: Airframe, Avionics, Engine, Energy]

[Features: high-precision scanning, strong stealth performance, weak radiation signal]

[Source point: 5.64 (can be enhanced)]

Upgraded two levels in a row.

Prefixes and entries have changed.

Two more features.

And it enters the non-upgradeable state again.

Looking at the drone's brand-new system panel, Tang Rui entered deep thought.

Follow the previous upgrade experience.

If you want to upgrade your drone to level 7, you'll need to harden your equipment.

And you can only upgrade after all the equipment has been strengthened.

A drone is not a fascia gun.

The equipment and systems that make up the UAV, there are too many.

If it is comprehensively strengthened, the source points required are estimated to be dozens, or even hundreds.

Come to think of it.

He was a little speechless.

There are also too many source points that are required.

"Strengthen the engine first and see how it goes."

Tang Rui decided to ignore so much and strengthen the engine first.

Select the Harden Engine.

Moment.

Several options appear.

Structural strengthening, material strengthening, turbine strengthening, combustion chamber strengthening, compressor reinforcement and nozzle reinforcement.

Among them, structural reinforcement and material reinforcement require 5 source points, while the rest of the reinforcement only needs 2 source points.

Tang Rui thought about it and chose structural strengthening.

In fact, material reinforcement is also very important.

But the problem is that even if he strengthens the material, he needs to start over.

It's hard to say whether it can be done or not.

The structure is different.

Once enhanced, he can 3D scan it and use it directly.

So for him.

The benefits of strengthening the structure are relatively high.

Swish.

With a glimmer of light, the reinforcement was complete.

The structure of the engine is strengthened, which is not visible from the outside.

He towed the drone to the car and drove home.

By the time I got home, it was almost four o'clock.

The original sleepiness has disappeared.

"Staying up late is bad for your body, so let's stay up all night."

After muttering a sentence.

He dragged the drone into the basement.

"Let's go!"

Place the drone on the workbench, pick up the tools, and start disassembling the engine.

He wanted to know.

What is the situation with the strengthened engine structure?

Half an hour later.

One engine was taken apart by him.

Tang Rui took the 3D laser scanning equipment and began to scan the engine in all directions.

On the computer screen next to him, a three-dimensional model of the engine slowly appeared as he scanned it.

Wait until he's done scanning.

I took the computer and looked at the engine structure on it.

A problem was discovered at the first time.

The overall structure of the engine at the moment is too complex.

"This is a variable bypass ratio structure combining a single duct (turbojet) with a double duct (turbofan)."

Tang Rui took a closer look and found that the overall structure of the engine had changed a lot.

Especially variable bypass ratios.

This thing can also be regarded as a kind of black technology that goes off the rails.

What is a bypass ratio?

To put it simply, it is the ratio of the air flow rate of the engine duct to the inner duct.

Current aircraft engines, bypass ratios are fixed.

For example, the engine of the F-22 has a bypass ratio of 0.29.

And our J-10 and J-15, the bypass ratio is in the range of 0.6-0.8, I don't know how much.

So here's the problem.

Is it better to have a larger or smaller duct?

The answer just depends on the situation.

For aircraft that do not need supersonic cruise, a duct is better than a larger one.

For aircraft that require supersonic cruise, a duct is better than a small dot.

That's just the approximate meaning.

Ordinary people understand this, and that's it.

So what is the situation with the black technology of variable duct ratio?

It is when cruising at subsonic speed, the engine is in a state of large bypass ratio, and additional air enters the combustion chamber, which makes the fuel burn more fully, increases thrust and reduces fuel consumption.

When entering supersonic mode, the valve closes and only a small part of the air enters the outer duct, which is responsible for cooling and afterburner.

This change increases the thrust-to-weight ratio of the engine and is also more fuel-efficient.