How do China's supercomputers and wind tunnels function in the design of its aircraft?


Tianhe-2. (Wikimedia Commons photo)

TAIPEI (Taiwan News) — The West has been very concerned about its technologies being used by Beijing's security apparatus for the surveillance of Chinese citizens.

While the Trump administration took positive steps to curtail the export of Western technologies to China for fear of enhancing its competitiveness, we still need to assess China’s technological capabilities lest we lose sight of the bigger picture.

China’s supercomputers

Among the world's 500 fastest supercomputers in 2020, 227 were Chinese. China's Sunway TaihuLight and Tianhe-2 are ranked the world's third and fourth-fastest, respectively.

This article is meant to argue that this superficial phenomenon could be misleading.

Building supercomputers is no longer out of reach for ordinary researchers with ample funding. They can simply stack up powerful commercially available processors and fast memory cards to integrate such an energy-hungry beast.

Though China claims Sunway TaihuLight is comprised of indigenous processors (Sunway SW26010), it's nevertheless based on the DEC Alpha architecture from the U.S.

Tianhe-2 uses nothing but Intel processors. Moreover, both computers' operating system is Linux. Compilers on all Chinese supercomputers — the software that translates and optimizes human logic instructions into a machine-readable format — all come from U.S.-invented GNU or Intel.

That means the foundation of China's supercomputers is based on Western technology, not their own innovative research.

Most importantly, it's the application software that determines the utility of parallel supercomputers. More often than not, such software has to be crafted carefully to make full use of the underlying parallel architecture.

From publicly available information, it seems both the Chinese supercomputers mentioned above have mostly non-military applications, such as meteorological and chemical reaction modeling. However, if we look at the accuracy of China's weather forecasts, one can reasonably doubt how innovative and proficient the China Meteorological Administration (CMA) has been in developing weather models and software.

In fact, most of CMA’s weather applications are still being executed on older IBM Flex networked servers. It's true that CMA also has two indigenous Sugon TC4600 supercomputers built upon Intel technologies, though it remains dubious how much of the parallelism potential has been exploited in the machines.

For operating systems, the system software that manages computer hardware, software resources, and provides common services for computer programs, China lags far behind the U.S.

Security and the risk of backdoors in devices from Western vendors are some of the main motivations for China to develop its own operating system. The results have been dismal at best.

For example, China embarked on the path to develop its indigenous versions, such as China Operating System (COS) and Unity Operating System (UOS), both of which are based on Linux-variant architecture. While UOS claims to support China’s own CPUs, COS has been accused of copying from Android.

It remains to be seen if any of China’s indigenous operating systems can take off.

The role of supercomputers in aircraft design

Another important application area for supercomputers is aerospace. China in the past has been known to import, legally or otherwise, computational fluid dynamics (CFD) software from various Western institutions, including NASA.

However, the fact that China's aircraft development still heavily relies on very expensive, power-hungry wind tunnels may be an indicator that the CFD software running on supercomputers may not serve the purpose of designing aircraft.

Huawei delivered its first supercomputer using its own Kunpeng 920 processor to the AVIC Aerodynamics Research Institute (AVIC ARI) in October 2019. Established in 1955, the AVIC ARI is China’s preeminent research arm in aerodynamics and has a campus in Shenyang (626 Institute) and another in Harbin (627 Institute).

Wind tunnels in aircraft design

AVIC ARI has 13 wind tunnels altogether and supports the design and development of J-11 (Russian Su-27SK), J-15 (Su-27K), J-16 (Su-30MKK), and J-31 aircraft (China’s second stealth fighter) as well as various missiles by the Shenyang Aircraft Corporation, which is under the Aviation Industry Corporation of China (AVIC).

The peak performance of Huawei’s supercomputer is 1.3 PFLOPS, about 100 times slower than the world’s fastest supercomputer — IBM AC922. It’s unclear what applications AVIC ARI runs on the machine, though given its status as a new installation, its full potential may have yet to be exploited.

Located in Mianyang, Sichuan, the China Aerodynamics Research and Development Center (CARDC) has been under the PLA’s Strategic Support Force (PLA Unit 63820) since 2016. With 2,000 researchers, four wind tunnels, and a supercomputer to aid aircraft design, CARDC is believed to have supported the Chengdu Aircraft Industry Group’s development of the J-10 and J-20.

It’s unclear what CFD software CARDC and AVIC ARI employ to design aircraft. The few papers published by their researchers in the public domain do not seem to be of superior quality.

In the early days of aviation, wind tunnels were used to see how new aircraft designs would fly. Nowadays, they are more likely to be used for verification and certification purposes.

Aerodynamics is an engineering problem that has been solved by the development of high-performance computers able to perform complex CFD simulations. This software enables engineers to show how “flows” of wind will dynamically interact with 3D digital models.

Today, wind tunnels are used to verify computer simulations at different stages of aircraft R&D. Therefore, CFD is only as good as the people’s knowledge of the physics of fluid dynamics and related aircraft design issues.

As for the development of the J-20, we still do not know how well it performs. Intellectual property theft from the West is one possibility, though outside help seems likely as well.

Given the fact that former DLR employees from Germany have helped China develop its LM-5 rocket engine, it’s highly likely that China has sought external help to design the J-20. Through this model, some advanced technical information regarding stealth fighters may have been transferred similarly.

Peeking into energy consumption

In any case, to peek into exactly how China is using its wind tunnels and/or supercomputers to aid in military aircraft design, one could dig into the electricity bills of the institutes mentioned above.

Depending on what “flying on the ground” tests are conducted, a wind tunnel could consume up to 250 megawatts of electricity per hour. Supercomputers also consume a lot of energy, but nowhere near that of the wind tunnel on an hourly basis.

For example, China’s Tianhe-2 could consume up to 18 megawatts per hour, enough to support a town of 35,000 residents. But the way the tools are used is different. Supercomputers tend to stay on all the time, while wind tunnels are powered up only when they are needed for a short period.

Examining the energy bills could yield insight into how and when supercomputers and wind tunnels are being used in China’s aircraft design. Such insight could help the outside world understand China’s technological prowess.

U.S. assistance to develop China's aircraft avionics

Many American aerospace companies, some of them global giants, have established joint ventures (JV) with China under the auspices of the Commercial Aircraft Corporation of China (COMAC) C919 commercial aircraft program. For example, Honeywell partnered with COMAC and transferred technologies spanning flight management systems, cockpit systems and displays, turbine engines, inertial navigation systems, and air data sensors.

Rockwell Collins, another U.S. aerospace giant, established a joint venture with the Aviation Industry Corporation of China (AVIC), a Chinese state-owned aerospace and defense conglomerate. The purpose of the joint venture is for Rockwell to teach AVIC systems engineering, software development, avionics testing, systems integration, and integrated surveillance.

Another of Rockwell’s JVs in China is for transferring expertise on how to design and manufacture full-motion flight simulators to the Chinese. The simulators can be used to train both commercial and military pilots.

Rockwell has been working with the Chinese aviation industry for more than 30 years. The company’s electronics are found in many airplanes manufactured in China, including the Shaanxi Y-8 (运-8) and Harbin Y-12 (运-12) military transport aircraft, both of which can be used to transport troops and weapons systems. Airplanes of both models have been outfitted with electronic surveillance measurement equipment to spy on China’s neighbors, such as Taiwan and Japan.

General Electric also established a joint venture with AVIC to teach the Chinese how to build avionics, displays, flight recorders, and flight management systems, among others technologies, under the COMAC C919 program.

Some Western aerospace companies have teamed up with the China Electronics Technology Group Corporation (CETC), a state-owned enterprise administered by the State Council. Constituted by 47 institutes, CETC has over half a million scientists and engineers tasked with developing China’s aerospace and defense capabilities. With assistance from the West, CETC and its subsidiaries have participated in many Chinese aircraft programs, including for fixed-wing and rotary-wing aircraft, some of which are military.

Most of the above-mentioned technologies are dual-use in nature. Since everything is under state control in China, it is a foregone conclusion that there is no firewall between civilian and military technological programs to prevent dual-use technologies from migrating to the military.

This is a dangerous trend, especially since the U.S. aerospace industry has done so much business with China that Beijing can now have a say in merger and acquisition activities in the industry. In 2017, United Technologies Corp.’s takeover of Rockwell Collins could not have been completed without the approval of Chinese regulators.

Why so many advanced aerospace technologies are allowed to be transferred to China is beyond the imagination of any sensible observer. The U.S. government must enact a functional legal framework to stem the outflow of such transfers before it’s too late.

Holmes Liao has more than 30 years of professional experience in the U.S. aerospace industry and served as an adjunct distinguished lecturer at Taiwan’s War College from 1999 to 2002.

Updated : 2021-04-10 20:39 GMT+08:00