BBS:      TELESC.NET.BR
Assunto:  Chinese scientists claim to expose B-21 flaws
De:       Mike Powell
Data:     Tue, 5 May 2026 09:12:14 -0500
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'Flaws identified in the B-21 configuration': Chinese scientists claim their 
mysterious PADJ-X stealth design software exposed major weaknesses in the 
USAFs B-21 Raider program using digital twins

Date:
Mon, 04 May 2026 19:05:00 +0000

Description:
A Chinese simulation tool modeled the B-21 using public data, claiming 
aerodynamic gains while raising questions about accuracy and intent.

FULL STORY
A Chinese aerospace simulation tool
called PADJ X has reportedly identified aerodynamic and stability limitations 
in Americas most advanced stealth bomber, the B-21 Raider. 

The software operates as an integrated platform that combines five major 
disciplines: aerodynamics, propulsion, electromagnetics, infrared signature, 
and sonic boom design. According to a peer-reviewed paper published in Acta 
Aeronautica et Astronautica Sinica, the researchers applied 288 parameters to 
simulate a B-21-type layout, using publicly available imagery rather than 
classified specifications.

Claimed capabilities exceed existing Western platforms -- Their analysis
claimed that aerodynamic optimization could increase the aircrafts lift-to-
drag ratio by 15%, while reducing shock wave effects that degrade stealth
and efficiency.

The PADJ X system uses adjoint optimization technology to calculate optimal 
design directions across all parameters simultaneously, reducing 
computational costs compared with traditional trial-and-error methods. 

A Chinese researcher noted that the software boasts full intellectual 
property rights and enables comprehensive optimization of aircraft 
aerodynamic configurations. 

Western platforms such as NASAs FUN3D and Germanys FLOWer solvers do not 
integrate as many physics disciplines into a single environment.

These existing systems often require manual adjustments when moving 
optimization from one discipline to another, making multi-objective tuning 
slower and more fragmented. 

PADJ Xs all-at-once approach suggests a step forward in integrated aircraft 
design, but its practical impact on real-world stealth bombers remains 
unproven. Available data suggests a functional but unverified system The 
leaked 20GB of files associated with PADJ X contain earlier versions of the 
project, including work on the Northrop Grumman X-47B drone and the Chinese 
CHN-F1 benchmark model.

Individual components of the software pipeline have been verified to operate 
correctly, including radar cross-section calculations run in third-party 
tools such as Altair FEKO. 

However, running a full multi-parameter geometry optimization from scratch 
would require more computing power and time than has been publicly 
demonstrated. 

The research papers referenced in the leak  numbers 
10.7527/S1000-6893.2025.32221 and 10.7527/S1000-6893.2025.32816  cannot 
currently be found anywhere, even in Chinese-language repositories. 

Access to these documents appears either to have been tightly restricted from 
the outset or to have been removed after the leak from the National 
Supercomputing Center of China. 

The absence of verifiable access to the final December 2025 software package 
leaves room for doubt, as does the convenient narrative of a mother of all 
leaks that cannot be independently confirmed. 

What remains unclear is whether Chinese scientists genuinely cracked the 
B-21s aerodynamic limits or whether the entire episode serves a different 
strategic purpose. 

The leaks may rely mostly on open-source imagery and publicly known design 
constraints rather than genuine espionage. 

This suggests that the claims could blend real technical capability with a 
carefully managed narrative aimed at influencing perceptions of U.S. stealth 
superiority. 

Via SCMP

Link to news story:
https://www.techradar.com/pro/flaws-identified-in-the-b-21-configuration-chine
se-scientists-claim-their-mysterious-padj-x-stealth-design-software-exposed-ma
jor-weaknesses-in-the-usafs-b-21-raider-programme-using-digital-twins-and-damn
ing-files-in-the-mother-of-all-leaks-from-china-suggest-the-secret-code-has-al
ready-cracked-the-bombers-aerodynamic-limits

$$
--- MultiMail/DOS
 * Origin: Capitol City Hub (1:2320/105)

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