China's New Stealth Drone May Revolutionize Next-Gen Fighter

[beijingwalker]

China's New Stealth Drone May Revolutionize Next-Gen Fighter​

2/10/2023 1:07:16 AM

China has been testing a new stealth drone design that does away with moving control surfaces and uses bursts of compressed air to maneuver. This testbed drone could influence its upcoming sixth-generation fighter designs.

The new drone features active flow control (AFC) technology, which uses bursts of high-pressure air from actuators embedded in the aircraft's body for maneuvering instead of traditional moving control surfaces such as ailerons, rudders, and elevators.

This week, the south china morning post reported that researchers with the China Aerodynamics Research and Development Center in Sichuan had tested a new flying-wing drone that uses AFC technology.

The SCMP reports that in a paper published on January 19 in the peer-reviewed journal Acta Aeronautica et Astronautica Sinica, Chinese researchers said that during the test flight, the drone climbed, rolled, and adjusted to turbulence imbalances while its ailerons were locked in place.

The source says that feat was accomplished by an actuator harnessing compressed air from the drone's engine and placed under the wing that controlled airstreams in different directions. The actuator generated enough torque for steering by forming a powerful but carefully calibrated layer of air around the drone's wings, enabling it to maneuver as effectively as aircraft with moving control surfaces.

The researchers noted that their drone was able to carry out smooth and quick maneuvers, with a response of less than 0.02 second from order to action, which is well within the capabilities of its flight computer.

The SCMP report says this technology has significant implications for designing stealth aircraft, especially in maintaining stealth shaping.

“The shape of a stealth aircraft has been carefully designed for aerodynamics and low observation,” says Zhang Liu, a scientist who led the research team at the exact center involved in designing China's J-20 fifth-generation stealth fighters, and hypersonic weapons, as quoted by the source.

As reported by the SCMP, the research team found that mechanical control surfaces could disrupt the careful shaping of stealth aircraft by producing gaps, sharp edges, and bumps, bringing additional drag and radar reflection areas.

However, according to the source, the research team noted that drawing too much fresh air from the aircraft's engine could result in a loss of thrust. Despite that, the SCMP reports that the research team's design diverts excess air from the drone engine's compressor, effectively“decoupling” gas collection and thrust generation. It also says the researchers found a way to cool large volumes of hot airflow, but did not disclose how.

Not to be outdone, this month aerospace testing international reported that US researchers had accomplished a similar feat as their Chinese counterparts, successfully testing a jet-powered sub-scale tailless aircraft. The source notes that the US team's drone used a combination of conventional control surfaces and AFC technology to maneuver.

The source reports that the US team launched their drone from Pendleton Unmanned Aircraft System (UAS) Range in Oregon last October for two nine-minute flights.

Aerospace Testing International reports that during each flight, one pilot launched the drone with conventional controls, switched to AFC mid-flight, and handed over control to another pilot.

The source notes that it initially took a lot of work to keep control of the drone. Still, as the pilots gained confidence in their skills, they could execute roll and pitch maneuvers to test their AFC's ability to steer the drone at steep angles and noted that the AFC system generated more power than predicted in wind-tunnel tests.

The source also says AFC has the potential to allow maneuvers that are impossible with traditional moving control surfaces, including high-speed turns and flying at angles that would make conventional control surfaces ineffective. This ability could be helpful in within-visual-range (WVR) aerial engagements and air combat maneuvering.

In addition, asia times has reported on another US AFC-technology project called the Control of Revolutionary Aircraft with Novel Effector (CRANE) X-Plane program. As with China's new flying-wing drone, the X-Plane features no moving control surfaces. But in contrast to China's AFC stealth drone, which has already been tested, the X-Plane is still in development, with a high subsonic demonstration flight planned in 2025.

Active flow control may be one of many new technologies featured in China's future combat aircraft designs, with potentially more advanced versions of AFC in the pipeline. In line with this, China developed plasma AFC technology last August that could be integrated into its upcoming H-20 stealth bomber.

Unlike traditional AFC, which uses high-pressure air to maneuver an aircraft, plasma AFC works by using a thin membrane in front of a flying wing aircraft, which ionizes air molecules. The ionized air molecules generate a plasma shower that accelerates the airflow, which can keep the aircraft from stalling if it goes down a particular airspeed.

For example, China's plasma AFC is claimed to prevent stalls even if the aircraft's speed drops to an unusually low 108km/h.

Apart from that, AFC technology may feature in China's sixth generation of fighters. The scmp reported last month that the Aviation Industry Corporation of China (AVIC), a leading Chinese state-owned aerospace corporation known for producing fighters such as the J-20, J-16, and J-10, released concept art of a sixth-generation fighter showing a tailless design.

asia times has previously noted that while there is no universally agreed definition of what a sixth-generation fighter is, such designs will likely include emerging technologies such as modular design, machine learning, artificial intelligence, virtual and augmented reality, manned-unmanned teaming, optionally manned capability, and most likely China's take on AFC technology.

As reported by the SCMP, China's sixth-generation concept art shows three aircraft resembling the fifth-generation J-20, but notably lack tails, fins and canards, feature a blended-wing body, and a fixed-wing design featuring no visible joints between the aircraft's body and wings. In addition, China's sixth-generation fighter will likely employ moving control surfaces, thrust vectoring, and AFC for maneuvering.

While the SCMP notes that while China's sixth-generation fighter designs remain highly classified, analysts quoted by the source say these design features will increase the aircraft's stealth compared with previous fighter generations, increase fuel efficiency, and make them competitive to their US counterparts.

China's New Stealth Drone May Revolutionize Next-Gen Fighter

China has been testing a new stealth drone design that does away with moving control surfaces and uses bursts of compressed air to maneuver. This

menafn.com

 

[jhungary]

Active Flow Control is not anything new. DARPA has been researching it since at least 2010, and MIT have actually made the first AFC craft back in 2018.

MIT engineers fly first-ever plane with no moving parts

MIT engineers have flown the first silent, fuel-free “ion plane.” The light aircraft is the first plane to fly with no propellers, turbine blades, or other moving parts.

news.mit.edu

 

[serenity]

AFC is nothing new but also no in service military craft uses AFC until China's GJ-11.

UK, China, and US have all been researching and playing/testing/experimenting with AFC for some time.

GJ-11 is the first active in service aircraft using AFC. GJ-11 reached service as far back as 2019 and that's disclosed service (just like J-10 was in service before official disclose service date and J-20 and so on).

Chinese military commentator speaking on GJ-11 in 2020 mentioned that it is much more useful and capable compared to previous generations of strike drones. The same person also mentioned that the PLA has better stuff than GJ-11. No detail given on whether those things are in service or he means the military industry is working on better stuff than GJ-11.

Even back in 2019 parade the GJ-11 was described as a new generation of strike drones using AFC. A world first in applying the technology and spoke of the UK research programs as an example of what AFC is.

Again the truth is everyone (most major players) have been researching forms of AFC for flight control for a long time. It's just that in every field that China is involved in, its efforts in the field are either totally silent, shroud in secrecy, or only mentioned that it is an ongoing thing. No details, very rarely are milestones and achievements mentioned except in a vague announcement.

 

[jhungary]

AFC is nothing new but also no in service military craft uses AFC until China's GJ-11.

UK, China, and US have all been researching and playing/testing/experimenting with AFC for some time.

GJ-11 is the first active in service aircraft using AFC. GJ-11 reached service as far back as 2019 and that's disclosed service (just like J-10 was in service before official disclose service date and J-20 and so on).

Chinese military commentator speaking on GJ-11 in 2020 mentioned that it is much more useful and capable compared to previous generations of strike drones. The same person also mentioned that the PLA has better stuff than GJ-11. No detail given on whether those things are in service or he means the military industry is working on better stuff than GJ-11.

Even back in 2019 parade the GJ-11 was described as a new generation of strike drones using AFC. A world first in applying the technology and spoke of the UK research programs as an example of what AFC is.

Again the truth is everyone (most major players) have been researching forms of AFC for flight control for a long time. It's just that in every field that China is involved in, its efforts in the field are either totally silent, shroud in secrecy, or only mentioned that it is an ongoing thing. No details, very rarely are milestones and achievements mentioned except in a vague announcement.

Pretty sure GJ-11 is not AFC, the photo shown in 2019 Parade have exhaust port. Maybe in the future version?

 

[serenity]

Pretty sure GJ-11 is not AFC, the photo shown in 2019 Parade have exhaust port. Maybe in the future version?

One form of AFC type control.
Basically I'm defining AFC as any new flight control method that uses gas/thrust instead of aerodynamic control surfaces.

GJ-11's thrust nozzles on the wing replacing all control surfaces. The GJ-11 frame is basically all non moving in that case. Which is what the state media essentially discussed. That a British experimental drone also uses this method. The difference is GJ-11 went into service and was commented on in terms of performance by PLA.

The problem is then they go quite silent about it all while only talking about it in snippets once in a while - "GJ-11 has replaced X and performs better than X because reasons 1,2,3." and then nothing. No images and videos allowed. While Cloud Shadow and the dozen other Chinese flying wing drones of mixed types are allowed to be discussed in somewhat greater detail in terms of speculation but most are development programs and not picked for service at least yet. Hence more secrecy with GJ drones.

American RQ series are also kept in relative high secrecy in this way too. Rarely talked about, known to be active in service but no images or videos allowed.

The PLA guy when he mentioned GJ-11 performing better than the drones it replaced, did mention that "there is better than GJ-11" not saying whether they mean better in development, in trials, or already in service. I would guess in development or trials since GJ-11 is still quite secretive despite mockups showing basically the outward look and its size.

 

[jhungary]

One form of AFC type control.
Basically I'm defining AFC as any new flight control method that uses gas/thrust instead of aerodynamic control surfaces.

GJ-11's thrust nozzles on the wing replacing all control surfaces. The GJ-11 frame is basically all non moving in that case. Which is what the state media essentially discussed. That a British experimental drone also uses this method. The difference is GJ-11 went into service and was commented on in terms of performance by PLA.

The problem is then they go quite silent about it all while only talking about it in snippets once in a while - "GJ-11 has replaced X and performs better than X because reasons 1,2,3." and then nothing. No images and videos allowed. While Cloud Shadow and the dozen other Chinese flying wing drones of mixed types are allowed to be discussed in somewhat greater detail in terms of speculation but most are development programs and not picked for service at least yet. Hence more secrecy with GJ drones.

American RQ series are also kept in relative high secrecy in this way too. Rarely talked about, known to be active in service but no images or videos allowed.

The PLA guy when he mentioned GJ-11 performing better than the drones it replaced, did mention that "there is better than GJ-11" not saying whether they mean better in development, in trials, or already in service. I would guess in development or trials since GJ-11 is still quite secretive despite mockups showing basically the outward look and its size.

Well, I am not @gambit and what I know about Aircraft is how to fly my Cessna, but what you are saying is similar to Propulsion Controlled Aircraft (PCA), which uses engine or engine thrust (and/or nozzle) to control the flight surface, without using traditional flap and rudder.

While this is part of AFC field, but this is a relatively old development. NASA started researching that since 1980s after Sioux United Airlines Flight 232 in 1989. they had developed a software to be used in a F-15 using propulsion to control the F-15 movement

Propulsion Controlled Aircraft (PCA)

With a Propulsion Controlled Aircraft (PCA) the airplane can be landed safely by using throttles only.

www.nasa.gov

And it was unwittingly performed by a crew of DHL Airbus in 2003 over Baghdad when a missile hit their hydrolic fluid storage and thus losing all their flight control other than thrust.

 

[serenity]

Well, I am not @gambit and what I know about Aircraft is how to fly my Cessna, but what you are saying is similar to Propulsion Controlled Aircraft (PCA), which uses engine or engine thrust (and/or nozzle) to control the flight surface, without using traditional flap and rudder.

While this is part of AFC field, but this is a relatively old development. NASA started researching that since 1980s after Sioux United Airlines Flight 232 in 1989. they had developed a software to be used in a F-15 using propulsion to control the F-15 movement

Propulsion Controlled Aircraft (PCA)

With a Propulsion Controlled Aircraft (PCA) the airplane can be landed safely by using throttles only.

www.nasa.gov

And it was unwittingly performed by a crew of DHL Airbus in 2003 over Baghdad when a missile hit their hydrolic fluid storage and thus losing all their flight control other than thrust.

Yes This form of AFC is a subset of it.

The experiments on other aircraft were done using main engines. I think aircraft like Su-57 use some form of it in combination with levcon to control flight. Basically some degree of minimizing control surface use or deflections. In GJ-11's case, it is totally to have zero aerodynamic control surfaces.

The F-15 experiment examples is yet another form where main engine thrust is used to compensate somewhat and experiment with the idea. Where this propulsion control has been taken in the modern era is in aircraft like GJ-11 or UK's BAe MAGMA.

MAGMA and GJ-11 are most comparable. Except only one of those are used for service and a active program rather than experimental program to research this form of propulsion control to get rid of aerodynamic control surfaces.

There are many forms of AFC that will probably be invented and it's just a broad definition.

What this article in OP deals with is quite old stuff. That's all. And seems to hype it too much when it is just at least in application on GJ-11 another way to make the aircraft a little more stealthy than it would be if it used aerodynamic control surfaces and their movements and gaps will spike RCS vs using this form of propulsion control with thrust coming out of six or more dedicated parts where it control output and vector according to what flight control system wants aircraft to do.

Mockup illustrating the propulsion control format.

I'm not even a Cessna pilot just adding what is known and vetted information that's publicly disclosed and available on the subject with regards to the OP.

 

[jhungary]

Yes This form of AFC is a subset of it.

The experiments on other aircraft were done using main engines. I think aircraft like Su-57 use some form of it in combination with levcon to control flight. Basically some degree of minimizing control surface use or deflections. In GJ-11's case, it is totally to have zero aerodynamic control surfaces.

The F-15 experiment examples is yet another form where main engine thrust is used to compensate somewhat and experiment with the idea. Where this propulsion control has been taken in the modern era is in aircraft like GJ-11 or UK's BAe MAGMA.

MAGMA and GJ-11 are most comparable. Except only one of those are used for service and a active program rather than experimental program to research this form of propulsion control to get rid of aerodynamic control surfaces.

There are many forms of AFC that will probably be invented and it's just a broad definition.

What this article in OP deals with is quite old stuff. That's all. And seems to hype it too much when it is just at least in application on GJ-11 another way to make the aircraft a little more stealthy than it would be if it used aerodynamic control surfaces and their movements and gaps will spike RCS vs using this form of propulsion control with thrust coming out of six or more dedicated parts where it control output and vector according to what flight control system wants aircraft to do.

View attachment 916207



Mockup illustrating the propulsion control format.

I'm not even a Cessna pilot just adding what is known and vetted information that's publicly disclosed and available on the subject with regards to the OP.

Well, I don't know, I mean, if OP really mean AFC as in the Zepher drone (like the one MIT made) then yes, this would be revolutionise drone and aviation, but if we are just talking about PCA, then this is a very old concept and have been used and dubbed all over, I believe all US Air Force aircraft have PCA system loaded, while the Air Force did not say they were being used, but when you see F-15 flying without a wing or A-10 got shot to bits and still able to come back alive, you know they are aboard.

The US Air Force probably won't do solid wing design even PCA has been in used since 80s because they don't do that kind of risk, I mean they invented PCA back then to help with situation when your craft is damaged and as a backup mode. The safety people in the Air Force probably will not approve solid flying wing design even with drone.

 

[serenity]

Well, I don't know, I mean, if OP really mean AFC as in the Zepher drone (like the one MIT made) then yes, this would be revolutionise drone and aviation, but if we are just talking about PCA, then this is a very old concept and have been used and dubbed all over, I believe all US Air Force aircraft have PCA system loaded, while the Air Force did not say they were being used, but when you see F-15 flying without a wing or A-10 got shot to bits and still able to come back alive, you know they are aboard.

The US Air Force probably won't do solid wing design even PCA has been in used since 80s because they don't do that kind of risk, I mean they invented PCA back then to help with situation when your craft is damaged and as a backup mode. The safety people in the Air Force probably will not approve solid flying wing design even with drone.

The use application is dfiferent. The US systems used PCA as a backup like you said. The application desire in GJ-11 is to maximize its stealth by using exactly solid wing design which the US in its application of PCA avoids since that isn't the point. But yes forms of PCA have existed for a long time.

I think the OP article means PCA applied in this way (solid wing and removing moving parts and gaps for stealth). I can't imagine how AFC as the MIT experiment can be applied to flying wing bombers drones or next generation fighters. It probably means the no moving parts, solid wing and increased stealth for those types of aircraft.

 

[jhungary]

The use application is dfiferent. The US systems used PCA as a backup like you said. The application desire in GJ-11 is to maximize its stealth by using exactly solid wing design which the US in its application of PCA avoids since that isn't the point. But yes forms of PCA have existed for a long time.

I think the OP article means PCA applied in this way (solid wing and removing moving parts and gaps for stealth). I can't imagine how AFC as the MIT experiment can be applied to flying wing bombers drones or next generation fighters. It probably means the no moving parts, solid wing and increased stealth for those types of aircraft.

Well, thrust vectoring and solid wing (or winglet) design has already been feature many times with Missile Technology. On the other hand, we wouldn't know what DARPA would come up with knowing how we already know the application with PCA. DARPA won't tell anyone anything

But as I said, US manned platform probably will not see solid wing design, whether or not PCA technology is being mastered, or whether or not stealth is considered it's like we will still put a driver seat and steering column on a fully automated car. But drones? Who knows,