Chapter 1182 Explosion Membrane Breaking Test
The JF-X mentioned by Jiang Zonglin is just a miniature wind tunnel with a length of 22 meters, a thickness of 0.2 meters, and an effective volume of 1,200 liters.
It can even be placed in an ordinary room.
Obviously, a JF-X of this size can basically not undertake any applied scientific research tasks, but it has designed a very complete wind tunnel structure including hydrogen/oxygen charging system, large vacuum unit of test section, ignition and detonation system, data acquisition system, etc.
And 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, which can adapt to the scaled wind tunnel test under most basic conditions.
At the same time, thanks to the relatively small size of JF-X, the difficulty of conducting experiments on it is also much lower.
Therefore, in less than two months, Jiang Zonglin and his team completed a set of forward detonation drivers, as well as the corresponding shock tubes and critical nozzles 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 quickly explained-
The purpose of this test was to verify the accuracy of the design method, not to really land the JF14 in advance.
Originally, for each subsystem of the entire Gaochao project, Chang Haonan adopted a task-driven management model that could better give play to the subjective initiative of each unit.
That is, setting phased goals and providing necessary support, but not too much dictating on specific work processes and methods.
But now he was just about to return to Beijing, 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 the JF-X wind tunnel that was about to be used for testing up close.
"This wind tunnel was developed jointly by us and North China University. We ordered two in total, which were deployed in Beijing and Bingzhou..."
Jiang Zonglin took Chang Haonan around to visit and introduced the basic situation of JF-X:
"In fact, given the situation at that time, we could not use this small-scale wind tunnel. Several comrades and I opposed spending this money...Looking back now, it was a bit short-sighted."
"Academician Chang, look."
He took two steps forward and pointed to a metal pipe section in the front of the main structure of the wind tunnel, which was obviously different in appearance 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 6.44m. It uses PCrNi3MoV gun steel, the inner diameter of the tube is Φ12, the design pressure is 75MPa, and the maximum operating temperature it can withstand is 5000-5500K..."
"..."
Just as he explained the details to Chang Haonan, the other two technicians had already bolted a circular diaphragm with a cross groove on the surface between the shock wave reflection chamber and the auxiliary detonation section.
"Don't underestimate this cross-grooved diaphragm."
When Jiang Zonglin 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 not only withstand the initial pressure, but also ensure that it can be fully opened after ignition and detonation, but it cannot be completely sheared off to produce fragments... It is the result of the research of several generations of people in the Institute of Mechanics, including Mr. Guo Yonghuai, Academician Yu, and Researcher Jiang. The cost is extremely low and the effect is better than similar foreign technologies..."
Although he had never seen the JF-X wind tunnel itself before, the detonation drive diaphragm was familiar to Chang Haonan.
It can be said that he knew it like the back of his hand.
He could even directly report that the one he had just installed was an A5 diaphragm with a total thickness of 8.40mm, a groove depth of 1.85mm, and a rupture pressure of 15.364MPa.
He just swallowed back the words that were on his lips because he was worried that his performance was too outrageous.
However, even so, it was enough to make the other party stunned.
"I neglected it."
After maintaining a dumbfounded expression for a while, Jiang Zonglin patted his forehead:
"Academician Chang must have known about the relevant situation before coming here..."
Chang Haonan smiled and did not comment on this.
Maintaining such a profound sense of mystery obviously helps him to carry out his work.
"Let's continue to introduce the preparations for the test."
Jiang Zonglin nodded:
"However, in our test today, this diaphragm only plays the role of cross-verifying the pressure of the outlet section 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 the A2-A4 diaphragms, and can only produce partial membrane breaking effects on the A5 and A6 diaphragms, and it is completely impossible to break through the diaphragms above..."
At this time, several staff members dragged two green and sky blue gas cylinders from the next room with a cart, and connected a rubber hose to each side of the laboratory.
Immediately afterwards, the sound of the air pump rang 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 in the hydrogen throat was 5.5MPa, while the inflation pressure set in the oxygen throat was 4.1MPa.
Considering the diameter difference between the two, the volume ratio is exactly about 2:1.
A few minutes later, the three red lights on the operating table turned green at the same time, indicating that the wind tunnel was ready to start ignition.
"Academician Chang, why don't you come?"
Jiang Zonglin gestured towards the button labeled "Start" on the console.
Chang Haonan hesitated for a moment, but did not shirk.
Since his rebirth, he has not done similar work for almost ten years. It’s also good to recall...
With this thought in mind, Chang Haonan stepped 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 an obvious intake of breath.
He turned around and took a look, only to find that Jiang Zonglin had a determined expression on his face as he was about to go to the examination room.
This made him almost laugh:
"Researcher Jiang, I'm not even nervous. Why are you nervous?"
Jiang Zonglin, who was a little unable to hold himself back, rolled his eyes secretly and said to himself, "You have never seen big winds and waves, so of course you are not nervous about this small scene."
But this is the first time that I use the algorithm I derived and analyzed to guide the design work. The psychological burden is of course different...
However, he felt a lot more relieved 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 drive section, a wisp of light blue arc light burst out from the tip of the electrode at the ignition point, touching the already fused gas in the container.
The hydrogen and oxygen mixed together in the most perfect proportion bloomed with dazzling light, like a fanatical flame elf, turning the entire space into an extremely gorgeous fireball.
The temperature of nearly 4000K and the shock wave exceeding ten times the speed of sound caused the air pressure to instantly reach hundreds of times its original level.
Originally, this process should only last a few microseconds.
But just when the peak pressure caused by the gas detonation was about to decrease, the peak of the shock wave happened to reach the inside of the shock wave reflection cavity, 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.
After 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.
Equilibrium pressure 8.753Mpa, peak pressure 15.8474MPa, steady state duration 5.631s...
The difference with his previous calculation was very small.
It fluctuates around 10%.
For an act powered by explosions, this is an incredible amount of precision.
About twenty minutes later, the technicians who returned to the wind tunnel laboratory removed the metal diaphragm at the exit of the shock wave reflector cavity.
The cross groove has been broken open by air pressure, but it has not been completely broken.
The data recorded on the computer just now was completely verified.
Jiang Zonglin's expression finally relaxed completely.
Sparse applause sounded in the control room.
But then, it became like a tidal wave.
There were even a few cheers mixed in.
Although for rigorous considerations, a series of supplementary experiments under different conditions will be needed later, this good start at least means that the entire design method is correct.
For Chang Haonan, he felt more satisfied than happy at this time.
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.
However, everything is left unsaid.