Chapter 1182: Explosion Membrane Breaking Test

The JF-X mentioned by Jiang Zongli is just a miniature wind tunnel that is 22 meters long, 0.2 meters thick, and has an effective volume of 1200 liters.

It can even be placed in an ordinary room.

Obviously, a JF-X of this size is basically incapable of undertaking any applied scientific research tasks, but it has been designed with an extremely complete wind tunnel structure that includes a hydrogen/oxygen inflation system, a large vacuum unit in the test section, an ignition and detonation system, a data acquisition system, etc.

Moreover, only a very small number of parts need to be replaced to flexibly adjust between the two working modes of forward detonation and reverse detonation, and it can adapt to scaled wind tunnel tests under most basic conditions.

At the same time, thanks to the relatively small size of the JF-X, the difficulty of conducting experiments on it is much lower.

Therefore, in less than two months, Jiang Zongli and his team completed a set of forward detonation driver, as well as the corresponding shock tube and critical nozzle according to the previously determined design method.

So much so that when Chang Haonan, who had just returned to Beijing from Gaojing, received a call saying that the Institute of Mechanics was ready for the first test and invited him to participate on site, he almost thought that he had made a mistake in the date because he was too involved in his work...

Fortunately, the actual situation was explained quickly.

The purpose of this test is to verify the accuracy of the design method, not to actually land the JF14 ahead of schedule.

Originally, for each subsystem of the entire Gaochao project, Chang Haonan adopted a task-driven management model that was more able to give full play to the subjective initiative of each unit.

That is, set phased goals and provide necessary support, but do not interfere too much in the specific work processes and methods.

But now he happened to be returning to the capital, and the other party took the initiative to invite him, so he was happy to be a witness.

……

In a laboratory in the corner of the first floor of the Institute of Mechanics, Chang Haonan saw up close the JF-X wind tunnel that was about to be used for testing.

"This wind tunnel was developed jointly by us and North China University. We ordered two in total, one in Beijing and one in Bingzhou..."

Jiang Zonglin took Chang Haonan around to visit and introduced the basic situation of JF-X:

“In fact, given the situation at the time, our institute could not really use this kind of small-scale wind tunnel. Several colleagues and I were against spending the money…Looking back now, it was a bit short-sighted.”

"Academician Chang, please take a look."

He took two steps forward and pointed to a section of metal pipe at the front of the wind tunnel's main structure that was obviously different in shape and material:

"This is the detonation drive section we designed. Because it is a forward drive, there is no need for a venting section... The total length, including the shock wave reflection chamber and the auxiliary detonation section, is 6.44 meters. It uses PCrNi3MoV gun steel, the inner diameter of the tube is Φ126mm, the wall thickness is 57mm, the design pressure is 75MPa, and the maximum operating temperature it can withstand is 5000-5500K..."

"..."

While he was explaining the details to Chang Haonan, the other two technicians had already bolted a circular diaphragm with pre-fabricated cross grooves on the surface between the shock wave reflection chamber and the auxiliary detonation section.

"Don't underestimate this cross-grooved diaphragm."

When Jiang Zongli said this, his tone was full of pride.

But before he could continue, Chang Haonan continued:

"I know that the outlet of the detonation drive section will be strongly impacted by the detonation wave, so this metal diaphragm must withstand the initial pressure and ensure that it can be fully opened after ignition and detonation, but it cannot be completely sheared off to produce fragments... This is the result of our... the Institute of Mechanics, including Mr. Guo Yonghuai, Academician Yu, and Researcher Jiang, who have been working together for several generations. The cost is extremely low and the effect is better than similar technologies abroad..."

Although he had never seen the JF-X wind tunnel itself before, the detonation-driven diaphragm was extremely familiar to Chang Haonan.

It can be said that I know them like the back of my hand.

He could even directly report that the one that had just been installed was an A8.40 diaphragm with a total thickness of 1.85mm, a groove depth of 15.364mm, and a rupture pressure of 5MPa.

He was just worried that his behavior might be too outrageous, so he swallowed back the words that were about to come out of his mouth.

However, even so, it was enough to leave the other party stunned.

"I was negligent."

After maintaining a dumbfounded expression for a while, Jiang Zonglin patted his forehead:

"Academician Chang must have known about the relevant situation before he came..."

Chang Haonan smiled and did not comment.

Maintaining such a high level of mystery obviously helps him do his job.

"Let's continue with the preparations for the test."

Jiang Zonglin nodded:

"However, in our test today, this diaphragm only plays the role of cross-verifying the outlet pressure together with the pressure sensor. According to our calculation results, the shock wave generated by the last hydrogen-oxygen explosion of JF-X can completely break through diaphragms A2-A4, and can only produce partial membrane-breaking effects on diaphragms A5 and A6. It is completely impossible to break through diaphragms above..."

At this time, several staff members dragged two gas cylinders, one green and one sky blue, from the next room with a cart, and connected a rubber hose to each side of the laboratory.

Then, the sound of an air pump was heard in the room.

Jiang Zonglin's introduction was also interrupted at the same time.

"Academician Chang, the drive section has begun to be inflated. Let's go to the control room to observe the situation..."

When the two changed into lab coats and came to the control room separated by a wall, the inflation process on the screen had entered a stable stage.

Chang Haonan glanced at the online monitoring instrument next to him and found that the gas source pressure set for the hydrogen throat was 5.5MPa, while the inflation pressure set for the oxygen throat was 4.1MPa.

Taking into account the difference in diameter between the two, the volume ratio is exactly about 2:1.

A few minutes later, the three red lights on the console turned green at the same time, indicating that the wind tunnel was ready to be ignited.

"Academician Chang, how about you come?"

Jiang Zonglin gestured to the button marked "Start" on the console.

Chang Haonan hesitated for a moment, but did not refuse.

Since his rebirth, he hasn't done anything like this for nearly ten years. It's good to recall...

With this thought in mind, Chang Haonan walked forward, pressed his right index finger on the surface of the button, and waited for the operator next to him to start counting down.

However, before someone read out the first number, he heard a noticeable inhalation.

When I turned my head and took a look, I found that Jiang Zongli had a determined expression on his face, as if he was about to enter the examination room.

This almost made him laugh:

"Researcher Jiang, I'm not nervous at all, why are you nervous?"

Jiang Zongli, who was a little overwhelmed, rolled his eyes secretly, thinking that you have seen all kinds of storms and waves, so of course you are not nervous about this small scene.

But this is the first time I use the algorithm I derived and analyzed to guide the design work, so the psychological burden is certainly different...

However, even though he was complaining in his heart, he felt a lot more relaxed after being interrupted by Chang Haonan.

"3..."

Jiang Zonglin began to count down in a deep voice:

"2...1..."

"start up!"

Following his order, Chang Haonan pressed the button that was familiar yet unfamiliar to him.

The next moment, inside the driving section, a ray of light blue arc light burst out from the tip of the electrode at the ignition point and came into contact with the gas in the container that had already merged.

The hydrogen and oxygen mixed together in the most perfect proportion emitted dazzling light, like a fanatical fire elf, turning the entire space into an incomparably gorgeous fireball.

The temperature of nearly 4000K and the shock wave that was ten times faster than the speed of sound caused the air pressure to instantly reach hundreds of times the original level.

Originally, this process should only last a few microseconds.

But just when the peak pressure caused by the gas explosion was about to drop, the crest of the shock wave just reached the inside of the shock wave reflection chamber, spreading the pressure relatively smoothly over the next few tens of milliseconds...

"puff--"

For everyone in the control room, they could only hear the faint sound of the gas being ignited.

However, although no one can observe the situation inside the wind tunnel, the pre-set sensors have faithfully fed back the data to the computer screen next door.

In less than 0.1 seconds, everything returned to calm.

"call--"

Looking at the room pressure curve in front of him, Jiang Zonglin breathed a sigh of relief.

Balance pressure 8.753Mpa, peak pressure 15.8474MPa, steady-state duration 5.631s...

The difference between this and his previous calculations was very small.

It fluctuates around 10%.

For an act powered by explosions, that's pretty incredible precision.

About twenty minutes later, the technicians returned to the wind tunnel laboratory and removed the metal diaphragm at the exit of the shock wave reflection cavity.

The cross groove has been opened by the air pressure, but it has not been completely broken.

This completely verifies the data just recorded on the computer.

Jiang Zonglin's expression finally relaxed completely.

Sparse applause broke out in the control room.

But then, it became like a tide.

There were even a few cheers mixed in.

Although for the sake of rigor, a series of supplementary experiments under different conditions need to be carried out later, this successful start at least means that the entire design approach is correct.

As for Chang Haonan, compared with joy, he felt more satisfied at this moment.

A kind of satisfaction after eliminating obsession.

"Congratulations, Researcher Jiang."

He smiled and held out his hand.

Although Jiang Zonglin was still immersed in excitement, he still held Chang Haonan tightly with both hands:

"..."

No words were spoken.

But, everything is self-evident.