223: Chapter 223 A twelve-ton assassin, there can't be a single flaw in his bones!

sentry ship arrival countdown, day 54.

Pangu Laboratory, Level B2, morning.

Academician Zhang Weide spent the last two days completing the second round of refinement on the structural nodes for the semi-embedded installation of the two engines.

From the bolt preload distribution on the mounting base to the thickness of the adhesive layer between the fuselage main beam and the skin, every item underwent at least two simulations.

This morning, he pushed the results of the second round to the public large screen.

"Chief Engineer Su, there is a new problem."

Su Che walked over from the main console.

On the large screen was the cross-sectional stress cloud map of the Mingdi Interceptor's mid-fuselage. Between the mounting bases of the two engines, there was a stress transmission belt running through the longitudinal axis of the fuselage.

"When both engines output asymmetric thrust simultaneously—for example, during a sharp left turn where the left engine reduces thrust and the right engine increases thrust—a torque is generated between the two mounting bases."

Academician Zhang Weide pointed to that belt on the cloud map with his engineering calculator.

"This torque is transmitted through the fuselage main beam, forming a shear stress concentration in the mid-section."

"The White Emperor and the Xuan Nu do not have this problem because they have multiple engines distributed symmetrically, so the contribution of a single engine's thrust change to the overall torque is shared by the other engines."

"The Mingdi Interceptor only has two, and there is no one to help share it."

Su Che looked at the peak shear stress numbers.

"Seventy-four percent. A margin of twenty-six percent, enough."

"It is enough for conventional operating conditions, but the Mingdi Interceptor is an interceptor. Its maneuver envelope includes a maneuver that neither the Xuan Nu nor the White Emperor has: a sudden stop and change of direction at top speed."

Academician Zhang Weide switched the simulation scenario to the next set.

"A sudden ninety-degree turn while cruising at 720 kilometers per second, with the thrust difference between the two engines pushed to the maximum, plus the superposition of inertial loads, brings the peak shear stress to eighty-seven percent."

"A margin of thirteen percent."

"Too thin."

Su Che stared at that set of data.

A thirteen percent margin is enough in the laboratory, but not on the battlefield.

Anything can happen on the battlefield; a micro-meteorite hitting the fuselage could weaken the local structural strength, and that thirteen percent margin would vanish in an instant.

"Thicken the mid-fuselage main beam."

"How much should it be thickened?"

"You calculate it; the target margin is over twenty-five percent."

Academician Zhang Weide returned to the supercomputer terminal, changed the parameters, and re-ran it.

Fifteen minutes later, the results came out.

"The main beam wall thickness increased from 4.2 millimeters to 5.8 millimeters, the mid-section weight increased by thirty-seven kilograms, the peak shear stress dropped to seventy-one percent, and the margin is twenty-nine percent."

"Impact on thrust-to-weight ratio?"

"Adding thirty-seven kilograms to a twelve-ton aircraft is three-thousandths; it is negligible."

"Approved."

Academician Zhang Weide locked the thickened main beam cross-section parameters into the blueprint and conveniently re-checked the adhesive layers of the three adjacent cross-sections as well.

Academician Sun Qiwen walked out of the U-shaped array area carrying a stainless steel thermos cup.

The enamel mug had been replaced at some point, and a handwritten label was stuck to the outer wall of the thermos, reading "Goji Berries and Red Dates."

"Chief Engineer Su, after thickening the main beam, the mounting base for the heat dissipation fins must be modified accordingly; the welding position at the root of the fins has shifted by 1.4 millimeters."

Su Che glanced at him.

"You are tracking even 1.4 millimeters?"

"A 1.4-millimeter shift in the weld at the root of the heat dissipation fins will reduce the fatigue life of the weld by twenty-three percent after 100,000 cycles under the thermal cycling stress of high-speed flight."

Academician Sun Qiwen placed the thermos on top of the cabinet. "The number of thermal cycles within the Mingdi Interceptor's design life far exceeds 100,000."

Su Che had Academician Zhang Weide correct the position of the heat dissipation fin mounting base.

...

sentry ship arrival countdown, day 53.

Level B2, afternoon.

Wen Bo came in with the second refined version of the stealth configuration plan.

The previous round had set the boundary conditions: giving up nozzle tail-end stealth within the atmosphere and applying a coating to the inner wall of the nozzle under closed-cycle operating conditions. This round of refinement focused on edge diffraction treatment for other parts of the fuselage.

"The biggest difference between the Mingdi Interceptor and the Xuan Nu or White Emperor is the wingspan." Wen Bo spread the plan drawings on the test bench.

"The Xuan Nu has a wingspan of twenty-five meters, the White Emperor thirty-two meters, and the Mingdi Interceptor eleven meters."

"A short wingspan means a short wingtip diffraction path, so the frontal RCS is naturally small, but the proportion of the side exposure area has actually increased."

Su Che stood in front of the test bench.

"The Mingdi Interceptor's combat mode is frontal entry, high-speed traversal, and withdrawal. The side exposure time is extremely short."

"Short does not mean non-existent."

Wen Bo flipped out a polar coordinate map of the radar cross-section.

"The frontal RCS is only 0.003 square meters, an order of magnitude smaller than the Xuan Nu, but in the thirty to sixty-degree side sector, the RCS jumps to 0.04, which is thirteen times larger than the front."

"Reason?"

"The lips of the two engine intakes on the side of the fuselage; the semi-embedded installation causes the lips to form a shallow groove with the fuselage, and this groove is a highly efficient reflector at side incident angles."

Academician Qian Zhenhua did not look up from his workstation on the east side, but his voice came over.

"Add serrations to the intake lips."

Wen Bo turned around.

Academician Qian Zhenhua still did not look up, speaking to his own draft paper.

"Make the lip edges serrated to break up the single specular reflection into small reflections in multiple directions, with the energy in each direction falling below the detection threshold. The luan bird's intake was handled this way."

Wen Bo thought for two seconds.

"The luan bird's intake diameter is over two meters, so the serrations are made on a centimeter scale. The Mingdi Interceptor's intake diameter is forty centimeters, so the serration size must be shrunk to the millimeter scale, requiring an order of magnitude higher machining precision."

"Use Zhu Long for the parts."

Zhou Dehai's voice came from the communication area; he was staying on Level B2 today and did not go to Kaitian Base.

"Using sub-nanometer equipment to cut millimeter-scale serrations is like using a sledgehammer to crack a nut; the precision is more than enough."

Su Che made a note on the plan drawing.

"Serrate the lips, process with Zhu Long, and re-calculate the side RCS."

Wen Bo collected the plan drawings and went back to make changes.

...

sentry ship arrival countdown, day 51.

Level B2, morning.

Two days had passed.

After Wen Bo's serrated lip plan was implemented, the side RCS dropped from 0.04 to 0.008, the same order of magnitude as the front.

Academician Zhang Weide's structure caught two more small problems in the third round of verification; one was that the fatigue life of the tail wing connecting pin was insufficient, which was solved by changing the material.

The other was the cockpit; the Mingdi Interceptor has no cockpit.

Purely unmanned.

While organizing the structural drawings, Academician Zhang Weide habitually left a space in the nose section, labeling it "Reserved."

Su Che saw it and didn't say anything.

Zhao Mingyuan appeared on the Mingdi Interceptor's R&D line for the first time today.

He had been working on the final optimizations for the White Emperor's swarm command module. Today, he handed the work over to two of his researchers and rolled his swivel chair to the front of the public large screen.

"Chief Engineer Su, I looked at the configuration table for the Mingdi Interceptor's main god ai airborne unit, and it uses the same model as the one used by the Xuan Nu."

"Correct."

"But the Mingdi Interceptor's mission characteristics are completely different from the Xuan Nu's. The Xuan Nu is a swarm node and needs coordination capabilities; the Mingdi Interceptor is a lone wolf and needs independent judgment capabilities. For the same AI unit, the weight distribution at the software layer should be different."

Su Che turned to look at him.

Zhao Mingyuan pushed the swivel chair half a step forward.

"For the Xuan Nu's AI unit, forty percent of the computing power is allocated to swarm coordination, thirty percent to tactical maneuvering, and thirty percent to fire control. The Mingdi Interceptor does not need swarm coordination; this forty percent of computing power should be poured entirely into situational awareness and autonomous avoidance."

"Why situational awareness and autonomous avoidance, and not fire control?"

"The Mingdi Interceptor's weapons are sniper cannons and torpedoes, which have a low firing frequency and low computing power requirements per shot. However, it needs to perform single-ship infiltration in deep space without wingman cover; if it encounters a threat, it can only run on its own."

"The computing power requirement for autonomous avoidance is even higher than for swarm coordination; swarm coordination is about communicating with teammates, while autonomous avoidance is about gaming against the entire battlefield."

Su Che confirmed this change.

"Write it into the AI unit's configuration document: reallocate weights: situational awareness forty-five percent, autonomous avoidance twenty-five percent, fire control thirty percent."

Zhao Mingyuan wrote the parameters on the inside of his sleeve.

He didn't know when he had developed this habit; the inside of his work uniform cuffs was covered with numbers and arrows.

...

sentry ship arrival countdown, day 50.

Level B2, afternoon.

Su Che summarized the progress of all subsystems at the core of the Mingdi Interceptor.

The third round of structural verification was completed, the second round of thermal management verification was passed, the stealth configuration including the serrated lip plan was locked, the communication deep space infiltration plan was locked, and the AI unit weight reallocation was completed.

The entire airframe skeleton was basically completed.

The remaining progress was focused on interface alignment between modules and the first round of cross-impact testing, which could be finished tonight.

He locked the progress schedule in the encrypted storage and stood up to stretch his waist.

Liu Huaqiang came out of the communication area, opened his notebook to the Mingdi Interceptor page, wrote a line of small text in the blank space with a pencil, and closed it.

"Chief Engineer Su, Zhou Dehai from Kaitian Base sent a message saying he is urging for the production schedule drawings for the first batch of trial-manufactured components for the White Emperor."

Su Che picked up his handheld device and glanced at the message sent by Zhou Dehai.

The White Emperor's design had been finalized for several days, and the drawings had been pushed over long ago. However, the White Emperor's components were much more complex than the Xuan Nu's, and the processing parameter requirements for Zhu Long required Su Che to provide a detailed manufacturing tolerance table.

"I will produce it tonight."

He placed the handheld device back on the desk and sat back down in front of the main console.

The Mingdi Interceptor's full-machine blueprint was rotating quietly on the main screen.

Twenty-two meters in length, eleven meters in wingspan, with two engines semi-embedded on both sides of the narrow, long fuselage.

Like a knife whittled down to nothing but the blade.

In the corner of the main screen, the sentry ship arrival countdown.

Fifty days.