I started with a ship full of max-level veterans, and I'm just a complete noob.

Jiang Ming extracted the drawing marked with the asynchronous reset terminal separately, put it into the inner cover according to the Class A document procedure, and then locked the cover into his personal briefcase.

Ren Xinmin retained the cross-page numbering and interface summary, and the original page numbers were recorded by two people separately to avoid any material losing its source evidence before verification.

"Rebuild the triggering conditions using an independent path tomorrow morning, without alerting the Soviet side."

Ren Xinmin closed the acceptance form, his finger still pressing on the column for the core interrupt controller.

"I trace back from the overall input, while you trace forward from the clock and registers. We determine the nature of the result after the two results meet."

Jiang Ming agreed and did not include the hidden loop in the public meeting minutes.

At this stage, they can only confirm that there are dangerous connections in the drawings, but they cannot yet determine whether this is a design flaw, a special protection logic, or a deliberately embedded control measure.

Any conclusion must be independently recalculated and device-level simulated. Premature accusations will only give the Soviet side the opportunity to retract the documents or change the interpretation.

In the afternoon, Jiang Ming took his briefcase and went to the calculation room of the Institute of Mechanics.

Guo Yonghuai had already laid out the temperature field draft of the variable cross-section throat on the long table, with several sets of temperature measurement data arranged along the axial direction, and the ignition and shutdown positions marked separately in red.

"The steady-state heat transfer in the front end has been closed; the problem lies in the reverse heat flow after shutdown."

Guo Yonghuai pushed a curve to Jiang Ming.

When the engine is working, the inner wall of the throat is subjected to a continuous heat flow, and a stable temperature gradient is formed in the material along the thickness direction.

After the machine is shut down, the high-temperature gas disappears quickly, and the cooling rate of the inner wall surface exceeds that of the interior of the structure. The residual heat begins to transfer back to the surface, and a reverse thermal stress wave is generated at the variable cross-section location.

Traditional steady-state formulas can only handle the smooth change of temperature gradient over time, and cannot cover the rapid switching at the boundary between ignition and shutdown.

Guo Yonghuai wrote three sets of partial differential equations on the blackboard: unsteady heat transfer, material expansion, and structural constraints. He also incorporated throat curvature as a spatial variable into the boundary.

When the calculations were performed in the variable cross-section connection region, the theoretical results broke down.

According to the existing model, the peak thermal stress should move continuously along the axial direction. However, the measured material sample showed local accumulation at the curvature change position, and the peak direction also deviated.

"The coefficient of thermal expansion of a material changes with temperature, and the existing linear relationship cannot contain this part. If we directly increase the empirical coefficient, we will have to refit the model when we change to a different material."

Guo Yonghuai put down the chalk and turned to look at the microscopic tissue photos on the table.

Jiang Ming arranged the three sets of photos side by side.

In the high-temperature region, lattice expansion is restricted by the curved surface geometry, radial deformation cannot be released independently, and stresses in the axial, circumferential and thickness directions begin to transform into each other.

His previous access to the academic networks of materials interfaces, device physics, and quantum physics through his network of contacts did not provide answers that could be directly applied, but it allowed him to determine from the microstructure which type of coupling was missing in the macroscopic equations.

Temperature changes not only alter the length of a material but also its local elastic response, and the variable cross-sectional curvature gives this change a directional difference.

Jiang Ming picked up the chalk and added a surface tensor compensation term to the end of Guo Yonghuai's equation.

This compensation incorporates the temperature-dependent coefficient of thermal expansion, curvature variation, and local material stiffness into the same coordinate system, allowing thermal stress to be redistributed among the three directions.

Guo Yonghuai did not immediately comment, but took the calculation paper and started recalculating from the boundary conditions.

On the first pass, he checked the dimensions and symbols.

On the second pass, he substituted the compensation term into the steady-state limit and confirmed that the equation could revert to the original model when the heat flow was smooth.

On the third attempt, he used sample data from the shutdown phase, and the local thermal stress peak finally fell into the measured range, with the deflection direction also consistent with the distribution of microcracks.

"Where did you come up with this idea?"

Guo Yonghuai placed the slide rule next to the surface tensor and focused his gaze on the coupling relationship in three directions.

"When I looked at the material photos, I found that the crack did not run along the direction of the maximum temperature difference. It turned at the location of the variable cross section, which indicates that the local stress is constrained by the curvature."

Jiang Ming only stated his judgments that could be supported by real-world evidence, without mentioning the academic context that unfolded from the depths of his consciousness.

Guo Yonghuai re-examined the photos and accepted this line of reasoning.

"You can judge the microstructure of materials faster than before; your engineering intuition has begun to penetrate to the underlying levels."

He copied the compensation item into the official draft and noted next to it that the measured heat flow in Jiuquan and the batch data of the materials needed to be further verified.

Jiang Ming compiled the discussion results into an English draft, with the core content revolving around the thermal shock of the variable cross-section throat, structural damping, and curvature constraints.

The first two letters to von Kármán had established a discussion on reentry thermal protection and nonlinear boundaries; the third reply needed to provide Jiang Ming's true technical perspective.

The newly added surface tensor term can precisely answer the question in the letter regarding the coupling between thermal shock and structural damping, and also demonstrates how the Chinese side constructs a verifiable model from limited measured data.

After he finished writing the core paragraphs, he didn't rush to seal the letter. Instead, he handed it over to Guo Yonghuai for review of the English terminology and physical boundaries.

Conversation could be heard outside the corridor as Vasily passed by the calculator room with his Soviet assistant.

He saw the table full of equations and photos of materials through the glass, and stopped to ask the translator to relay his message.

"The Soviet Union had already provided complete blueprints, but the Chinese side wasted its time on theoretical models that could not be manufactured. Such derivation would not allow the missile to take off sooner."

Guo Yonghuai was reviewing the compensation items and did not look up.

Jiang Ming neatly stacked the completed calculation sheets according to their numbers, but did not respond.

If the blueprints contain unverified hidden loops, the sooner they are installed into the equipment, the faster the risks will materialize.

If the thermal protection model leaves a gap in the shutdown impact phase, even if the projectile takes off on time, it may lose its structural integrity in the most dangerous position.

These judgments can only be confirmed through experimentation and recalculation; verbal disputes cannot replace any data.

Jiang Ming and Guo Yonghuai sealed the calculation paper and finalized the schedule for verifying the heat flow data after it arrived in Jiuquan.

The third draft reply was placed in a separate folder, awaiting review by Qian Xuesen and the security department before being sent out.

When they returned to 502 in the evening, Lao Sun was squatting next to the spare diesel engine, his hands covered in engine oil, while Fang Xudong was measuring the clearance of the nut of the speed regulating mechanism with a feeler gauge.

When a diesel engine is under low load, it will oscillate periodically, and the power supply voltage will fluctuate accordingly. If the high-frequency test bench is powered directly, even small fluctuations will be included in the pulse measurement results.

"The nut has been tightened, but the spring is still returning slowly."

When Lao Sun pushed the speed control lever back to its original position, there was a slight drag in the middle section when the spring pulled the mechanism back.

Jiang Ming put down his briefcase and took the feeler gauge to check the connection.

The nut clearance was not out of tolerance; the real problem lay with the spring preload. During the previous maintenance, the fixing point was loosened to reduce wear, resulting in insufficient tension on the return stroke of the speed control lever.

"Move the fixing point back one hole to increase the preload. Don't tighten the nut any further, or the return stroke will get stuck if the gap is too small."

Old Sun adjusted the spring as required and then had Fang Xudong connect the voltage recorder.

After the diesel engine restarted, the swing range of the speed control lever gradually narrowed, and the fluctuation of the test power supply was also brought back to the allowable range.

Liu came in from outside carrying a wooden box containing freshly cut silicon wafers. Each wafer was separated by a dust-free paper sheet, and the edges were marked with crystal orientation and batch number.

"The second round of seed crystal slicing is complete. The Institute of Physics just delivered it, and the quantity matches the handover form."

Jiang Ming counted each box and then randomly checked the edges and numbers of the slices.

"We will complete the cleaning and surface pretreatment tonight and start the next round of diffusion tomorrow morning. The furnace temperature profile will use the verified version, and the gas path feedforward parameters will be verified separately."

Fang Xudong took the handover form and arranged the diesel engine test and silicon wafer diffusion into two separate duty schedules.

The office intercom rang at that moment.

Jiang Ming wiped his fingers clean and picked up the receiver.

Director Wang's voice came from the other end of the line.

"The name Gu Shaowen has appeared. The railway investigation team has just found a ticket purchase record. The departure station is in the south, the destination is Beijing, and the date is two days before the note was sent."

Jiang Ming looked at the highest secure cabinet.

"Have you confirmed the train number, seats, and travel companions?"

"A temporary certificate was used, the name matches the file, and the destination after arriving in Beijing is still under investigation. An old suitcase was left at the train station's storage area."

Director Wang did not use the ticket purchase record as evidence for the arrest, but only ordered 502 to continue to maintain covert sentries. Gu Shaowen's photo had been sent to the three observation points.

"Don't set up surveillance openly at the station. If he really is the deliveryman, he might look for a second opportunity to make contact."

Jiang Ming put down the phone and returned to the confidential cubicle.