Chapter 939
Key Projects in the Secret Base
In a secret base deep in the mountains of Northwest China, the development of plasma engines has been underway for some time.
Zhū Jimin stood in front of the control panel, staring at the data flashing on the screen, his brows furrowed into a deep frown.
The magnetic field gradient problem in the pre-ionization chamber has been solved after Wang Donglai's guidance last time. The thrust oscillation has disappeared, and the continuous thrust stability has reached 99.97%. This data is enough for any aerospace propulsion laboratory in the world to boast about for three years.
But Zhou Jimin couldn't be happy, because new problems had arisen.
Thrust vector control.
Theoretically, plasma should flow in a perfect axial direction when it is ejected from the nozzle.
However, in reality, the interaction between the high-temperature plasma and the inner wall of the nozzle produces a complex boundary layer effect, which causes a slight deflection in the thrust direction.
The deflection angle is extremely small, approximately between 0.3 and 0.5 degrees. For a heavy rocket that is tens of meters tall, this deflection of a few tenths of a degree will be amplified by the length of the rocket body, ultimately resulting in an error of tens or even hundreds of kilometers in orbital accuracy.
A few dozen kilometers is nothing in low Earth orbit, but in the Earth-Moon transfer orbit at 380,000 kilometers, this error will be further amplified, eventually leading to completely opposite results.
"Chief Engineer Zhou, the simulation results for the thirteenth scheme are in."
A young engineer stood up, his voice a little strained: "The deflection angle is stable at 0.42 degrees, which is only 0.03 degrees better than the previous solution, and it's still far from our goal of 0.1 degrees."
Zhou Jimin remained silent.
He took off his glasses and slowly wiped them with his sleeve, a gesture he had made for over thirty years, every time he encountered a truly difficult problem.
Thirteen schemes were tested, including everything from the geometry of the magnetic nozzle to the layout of the additional magnetic field, from the pre-ionization ratio of the working gas to the material coating of the nozzle wall. Every conceivable variable was tried.
The best result is 0.42 degrees, which is still an order of magnitude away from the temporarily acceptable 0.1 degrees.
"Prepare the parameters for the fourteenth plan, and we'll run it tomorrow."
The young engineer hesitated for a moment: "Chief Engineer Zhou, the fourteenth and thirteenth plans only have minor adjustments to the nozzle expansion angle. Theoretically, the improvement will not exceed 0.01 degrees. Can we change our approach?"
Zhou Jimin put his glasses back on and glanced at the young man.
Change your approach? Of course he knew he should change his approach, the question was where to change it to.
Plasma boundary layer effect is a complex problem involving magnetohydrodynamics, plasma physics and materials science. There are no ready-made solutions available globally because no one in the world is working on a plasma engine with such high thrust.
They were the first to eat crabs, and those who ate crabs didn't have a recipe to follow.
"Let's start running."
“Data accumulation itself is also progress.”
The young engineer said nothing more and sat down to continue working.
The only sounds in the domed space were the low-frequency hum of the equipment and the occasional tapping of keyboards.
Zhou Jimin walked out of the main control area and walked deeper into the corridor along the edge of the dome.
He wanted to check on the progress of the anti-gravity device and clear his head.
The explosion-proof door at the end of the corridor opened, and in the hemispherical laboratory, Shen Li was squatting next to the platform recording data.
The fist-sized metal sphere remained quietly suspended about twenty centimeters above the table, as stable as if it were nailed to the void.
"Still the same as before?"
Zhou Jimin walked to her side and said softly.
Shen Li didn't look up, and calmly said, "As usual, the stability is perfect. After the magnetic field compensation system was upgraded, the anti-interference capability has improved by three orders of magnitude. The problem now is that we don't know where the upper limit of this thing is. Last month, the input power was increased by 7%, and the levitation height increased by 4.3 millimeters. This month, it increased by 15%, and the height increased by 9.1 millimeters. The curve is almost linear, without any signs of oscillation or instability. Chief Engineer Zhou, this is not normal. Any physical system will have nonlinear effects when it approaches its limit, but we haven't seen any."
Zhou Jimin stared at the suspended metal sphere for a moment before saying, "So you think its limits are far more than this?"
"I think it may not even have the kind of limits we understand."
Shen Li finally raised her head, her eyes filled with a rare confusion, which was quite unusual for someone who had become a full researcher at the Chinese Academy of Sciences at the age of thirty-two.
“I read the technical outline that Academician Wang gave me no less than fifty times. Every time I read it, I gained a new understanding, but after each understanding, I found new things I didn’t understand. It’s like his writing is layered, you open one layer and think you’ve seen the core, but there’s another layer inside.”
Zhou Jimin remained silent.
In fact, he felt the same way.
The technical outline provided by Wang Donglai appears to be a normal engineering document, with a theoretical framework, parameter ranges, and design principles.
But once you really delve into it, you'll discover that behind those seemingly simple parameter ranges lies a whole set of physical scenarios they've never encountered before.
It's like someone gives you a detailed map, and you follow the map to find the treasure, but you still don't understand how the map was drawn.
"Chief Engineer Zhou, how's the plasma work going?"
"We're stuck on thrust vector control. The deflection is caused by the boundary layer effect. We have thirteen different schemes, and the best result is 0.42 degrees."
Zhou Jimin gave a wry smile and continued, "We'll be running the fourteenth set tomorrow."
Shen Li nodded and didn't ask any more questions.
Unlike Zhou Jimin, she didn't believe in "running data and trying her luck".
Her work style is more like solving a math problem; if she can't solve it, then there must be a problem with some fundamental assumption.
However, the development of anti-gravity devices is still in the theoretical verification stage, and there is still a long way to go before encountering real challenges.
The two stood in silence for a while, then returned to their respective posts.
The next morning, just as Zhou Jimin was about to start the simulation of the fourteenth scheme, the base's secure communication system suddenly lit up.
The staff member stood up and walked to Zhou Jimin's side with a hint of excitement in his voice, saying, "Academician Wang's car will arrive at the base in ten minutes. Notify all experimental areas to prepare."
The atmosphere of the entire dome space changed instantly.
No one spoke loudly, but everyone moved a little faster.
It wasn't nervousness, it was anticipation.
Wang Donglai last came a month ago. That time, he spent three minutes looking at the data, two minutes deriving the results on the whiteboard, and then solved the magnetic field gradient problem that had been troubling them for more than seven months with just one sentence.
Zhou Jimin can still recite that sentence verbatim: "It's not a problem with the constraint structure, it's that the magnetic field gradient of the pre-ionization chamber is designed to be too steep."
That one simple sentence pulled them out of a dead end.
Ten minutes later, Wang Donglai entered the dome space on time.
Zhou Jimin stepped forward, about to report on the preparations for the fourteenth plan, but Wang Donglai spoke first. "Chief Engineer Zhou, after the last problem was solved, did you encounter another problem with thrust vector control?"
Zhou Jimin was taken aback for a moment, and said with some surprise, "Yes, you... how did you know?"
Wang Donglai did not answer the question. He walked straight to the main control panel and instructed the staff member next to him, "Pull up the deflection angle data so I can take a look."
Zhou Jimin quickly followed and gestured for the engineer to retrieve the data.
On the screen, the deflection angle curves of the thirteen schemes unfolded in sequence, like thirteen snakes of different colors, winding in the same coordinate system.
Each curve fluctuates between 0.4 and 0.5 degrees, and none of them can remain stable below 0.3 degrees.
Wang Dong looked at it for about two minutes.
Then he turned around and walked toward the whiteboard next to him.
Everyone in the dome stopped what they were doing and focused their attention on him.
Last time, he stood in front of that whiteboard and rewrote their understanding with five minutes of deduction.
This time, they are all hoping that the miracle from last time will happen again.
Wang Donglai picked up the marker, but did not write immediately.
Standing in front of the whiteboard, before he began to write, he turned to Zhou Jimin and asked, "Chief Engineer Zhou, have you been trying to use an additional magnetic field to correct the deflection?"
"Yes."
Zhou Jimin nodded affirmatively and said, "The boundary layer effect of plasma is essentially a magnetohydrodynamic instability. We tried to arrange a ring-shaped correction magnet around the main nozzle to constrain the plasma flow direction of the boundary layer by adjusting the magnetic field gradient. We tried thirteen schemes, with different magnetic ring arrangements, different magnetic field strength gradients, and different combinations of polar and circumferential directions."
Wang Donglai nodded, a knowing look on his face, and then said something that stunned everyone: "The direction is wrong."
The dome was so quiet that you could hear the hum of the liquid nitrogen cooling system.
You're going in the wrong direction!
If these four words were spoken by someone else, Zhou Jimin might disagree.
He has worked in aerospace propulsion for over thirty years, led countless projects, and solved numerous problems. Of course, he knows that his direction may not be optimal, but not just anyone has the right to make such a sweeping negative assessment as "the direction is wrong."
But the person who said this was Wang Donglai.
A month ago, he said something similar: "It's not a problem with the constraint structure," and then used a formula to overturn his efforts of more than seven months.
That overturning ultimately brought their thrust stability to 99.97%.
"Please give me your guidance, Academician Wang." Zhou Jimin's voice was calm, but there was a hint of excitement in his tone.
Wang Donglai picked up a marker and drew a simple diagram on the whiteboard.
It's not a complex magnetohydrodynamic equation, nor a partial differential derivation, but an extremely simple schematic diagram: a cross-section of a plasma nozzle, with the jet entering from the left and exiting from the right.
He drew a small bump on the central axis of the nozzle.
"The deflection of the thrust vector is essentially due to the asymmetry of the plasma density distribution within the nozzle. You are trying to use an external magnetic field to correct an internal density distribution problem, which is like a person who is walking off course. Instead of addressing their center of gravity, you tie a rope around their waist and pull them in the opposite direction. Can you pull them back? Yes, but it is extremely inefficient and unstable."
He drew a circle on that little bump.
"At the front end of the nozzle's central axis, a tiny physical protrusion is placed. No additional magnetic field is needed; only the internal geometry of the nozzle needs to be altered. The purpose of this protrusion is to actively create a controllable density perturbation before the plasma enters the nozzle. This perturbation propagates downstream along the nozzle axis, pre-compensating for asymmetry before the boundary layer forms. In other words, it's not about correcting the deflection after it occurs, but about eliminating the cause of the deflection before it happens."
Zhou Jimin stared at the simple diagram, his eyebrows furrowed slightly, his mind racing, and soon his breathing became rapid.
He understood!
Instead of using a magnetic field to correct it, the fluid's own properties are used to counteract it.
This is like changing the flow of a river upstream, rather than desperately building dams downstream.
The former is about using minimal effort to achieve maximum results, while the latter is about achieving twice the result with half the effort.
"You can actually do that?!"
"Just run it a couple more times on the Tiangong platform."
Wang Donglai put down his marker and continued, "The geometric parameters of the protrusion need to be calculated precisely. Height, curvature, and position—each variable will affect the final density distribution. A quantum computer can run through all the parameter combinations and find the optimal solution in a few hours."
Zhou Jimin turned around and called out to the young engineer in charge of magnetohydrodynamic modeling.
The young engineers were already typing on their keyboards, the Tiangong platform interface unfolded on the screen, and the 3D model began to be built.
Wang Donglai did not leave. He stood next to the main control panel, watching the young engineer input parameters.
Occasionally, he would offer a few reminders: "Expand the scanning range of the radius of curvature to three times the original size," "Move the starting position of the protrusion forward by five millimeters," and "Add the initial turbulence intensity of the working gas as a variable as well."
Every instruction was as precise as a surgical operation, without the slightest hesitation.
The parameters were quickly entered, and the Tiangong platform immediately began calculations.
As a domestic quantum computing platform, the Tiangong platform is actually divided into two versions: a commercial version and a version specifically provided to key departments.
Undoubtedly, the latter has greater computing power and stronger capabilities.
Therefore, it only took half an hour to run all the parameter combinations.
On the screen, the simulation result of the optimal solution immediately appeared: deflection angle, 0.08 degrees.
There was a three-second silence in the base, then someone started clapping. The applause started sparsely, then grew louder and louder, until it finally thundered.
Zhou Jimin did not applaud.
He simply stood in front of the control panel, staring intently at the near-perfect simulation curve.
The curve was as smooth as a taut string, stretching from the nozzle inlet to the outlet without the slightest fluctuation or deflection.
His eyes were filled with infatuation, as if he were looking at an unparalleled beauty.
Plasma engines are not a novel concept, but it was Wang Donglai who proposed this project. Behind this engine lies the aerospace fighter jet and the Nantianmen Project.
Although Zhou Jimin did not know everything, what he did know was already shocking enough.
At first, he didn't think it was possible, but after seeing the technical outline that Wang Donglai took out, and with Wang Donglai's several technical guidances, Zhou Jimin's confidence grew stronger.
Now, Zhou Jimin felt he had probably been too conservative; this project was no longer just unlikely to succeed, but was destined to succeed. (End of Chapter)