Posted on 01/11/2024 10:52:20 PM PST by Red Badger
Aurora Flight Sciences’ experimental active flow control aircraft is designed around a system that supplies pressurized air to effectors embedded in all flying surfaces, replacing traditional mechanical aerodynamic surfaces such as flaps and rudders. Photo: Aurora Flight Sciences
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The US Defense Advanced Research Projects Agency (DARPA) and Boeing’s Aurora Flight Sciences are working in tandem to produce an aircraft that utilizes pressurized air rather than physical surfaces for control, a revolutionary design with the potential to reshape the future of aviation and military stealth technology.
This month, Breaking Defense reported that the pioneering prototype, known as X-65, weighs 7,000 pounds and is designed to reach a maximum speed of Mach 0.7. The report says the new-fangled plane could take flight as soon as the summer of 2025.
The Control of Revolutionary Aircraft with Novel Effectors, or CRANE, program aims to break the mold of a feature fundamental to aviation’s century-plus existence by using active flow control (AFC) actuators to shape an aircraft’s flight.
The X-65 will be built with traditional control surfaces and the new actuators, with tests progressively “locking down” traditional flight control surfaces and gradually expanding the role of AFC devices, according to the Breaking Defense report.
The report says that the X-65 will be a valuable test asset for DARPA and other agencies long after CRANE concludes. It adds that the X-65 is designed as a “modular platform”, allowing it to be easily swapped out and serve as a test asset for DARPA and other agencies.
In January 2023, Asia Times reported that the X-65 is intended to serve as a testbed for new aircraft technologies with an eye on revolutionizing current stealth technologies. The CRANE program aligns with the evolution of stealth aircraft, as combat aircraft must improve performance and become more affordable and stealthier to maintain their strategic edge and value.
Innovations in inlets and exhausts are needed to conform to flying wing designs of future stealth aircraft. Advances in systems integration, miniaturization, actuators, sensors and computing power have made AFC technology feasible for military aircraft. Moving control surfaces, meanwhile, can impact aircraft radar cross sections (RCS), potentially compromising stealth.
AFC is more desirable than passive measures like traditional hinged flight control surfaces, as it can be turned on and off as required. AFC technology enables multiple opportunities for aircraft performance improvements including the elimination of moving control surfaces, drag reduction, the creation of thicker wings, increased fuel capacity, and simplified high-lift systems.
Future stealth aircraft, like the sixth-generation US Next Generation Air Dominance (NGAD), may use AFC to leverage multiple advantages afforded by the technology.
Concept art of the possible design for the US Air Force’s future Next Generation Air Dominance stealth fighter. Image: Boeing
In a January 2022 article for The National Interest, Alex Hollings notes that AFC can supplement or remove traditional moving control surfaces to improve aircraft flight performance and reduce mass and volume compared to conventional control surfaces, enabling greater payloads, speed and lesser maintenance requirements and leading to higher operational readiness rates.
Hollings notes that in cases where stealth is required, pilots can use AFC technology for broad control of the aircraft when flying in contested or heavily defended airspace, then transition to traditional flight control surfaces for life-or-death situations where maneuverability is needed such as in aerial dogfights.
Next-generation stealth drones may also feature AFC technology to improve their survivability in contested or heavily defended airspace.
In July 2022, Breaking Defense reported that the US Air Force plans to phase out its RQ-4 Global Hawk drones by 2027 to make way for newer drones that are more survivable in contested and defended airspace.
The US Air Force has described the RQ-4 as a “legacy” platform that offers limited capability against near-peer threats. However, the Breaking Defense report notes that divesting the RQ-4 too early might leave a significant intelligence, surveillance and reconnaissance (ISR) capability gap while a replacement is in the works.
The Warzone noted in an April 2021 article that the stealthy RQ-180 may take over the RQ-4’s ISR role and serve as a high-flying information and networking node.
While details are scant on the RQ-180’s specifications, The Warzone describes it as a large, twin-engine flying-wing aircraft with slender laminar-flow optimized wings whose design was mandated by highly advanced, broadband, all-aspect stealth requirements.
The Warzone mentions that the RQ-180 is meant to fly at high altitudes above 70,000 feet for prolonged periods without being detected. Later generations, or even the successor of the RQ-180, may feature AFC to further enhance its already formidable stealth characteristics.
Moreover, AFC may feature in the next generation of armed combat drones designed to penetrate heavily contested airspace and engage in high-tempo combat.
In September 2023, Asia Times reported on General Atomics and DARPA’s so-called “LongShot” program, a wingman drone designed to launch air-to-air missiles for beyond-visual-range (BVR) combat.
While the LongShot drone could use AFC to maintain stealth while moving into contested airspace, it could also switch to using traditional control surfaces for aerial combat maneuvers.
Increasing stealth may have refocused the spotlight on dogfighting skills, which have recently been de-emphasized in favor of BVR engagements. The increasing stealth of both fighters and drones means that opposing sides can end up within visual range (WVR) of each other, inadvertently ending up in a close-quarters fight.
At the same time, AFC technology still faces significant technical challenges, specifically in regard to miniaturization and diverse applications.
Artist’s concept of a drone swarm. Credit: C4ISRNET
In an October 2021 article in the peer-reviewed Annual Review of Fluid Mechanics journal, David Greenblatt and David Williams note that energy efficiency is a significant challenge in applying AFC in flapping-wing micro and nano-drones.
Greenblatt and Williams wrote that AFC systems have no dominant design philosophy or approach due to different control objectives, flight regimes and actuation methods. They state that design approaches vary depending on the specific application and objectives.
Greenblatt and Williams also state that the practical application of AFC involves comprehending the aerodynamics of control effectors and their interaction with flight vehicle dynamics using methods like experimental correlations, dimensional analysis, reduced-order modeling or high-fidelity computational fluid dynamics.
Aviation Ping!.......................
The fact that this is Asia Times reporting is a bit unsettling.
Yes but can they keep the doors on it?
It’s been reported all over the world in different publications..............
Well then... That’s just warm and fuzzy.
This is really interesting actually. They’re using technology to replicate the way a bird soars. If you watch it birds exercise the ultimate variable control surface adjusting their wing tips and twisting the leading edge to compensate for updrafts, wind shifts and turbulence. I had always wondered when the engineers would finally come to try and replicate that technologically.
Orville and Wilbur Wright used wing warping for the Flyer.
And what is the “Skunk Works” up to these days?
We were working on this concept over 30 years ago so it’s not exactly new.
Works well in combination with vectored thrust.
It’ll be interesting to see how well multiple bursts of air at varying temperature pluming around the vehicle compare with the IR signature of moving control signals.
Scotty: “The more they overthink the plumbing, the easier it is to stop up the drain.”
I bet PLA students and professors are present at University research on the subject. We are the world...
Hope Boeing can figure out how to keep the body panels on. Good thing they didn’t have DEI during WW 2/B-17 days. If it’s Boeing, I’m not going
Well, Asia Times is only reporting what the Chicoms are telling them to, and the chicoms are getting the Boeing plans in realtime directly from the pedojoe family, so at least there's a way for Americans to find out what our own government is up to.
“Plugs”
reading comic book?
The Wright Brothers Flyer used that ‘technology’, they called it ‘Wing Warping’. But Flaps and ailerons became the norm................
The Wright Brothers Flyer used that ‘technology’, they called it ‘Wing Warping’. But Flaps and ailerons became the norm................
We live in an age of wonders! Will be these aircraft be powered by batteries or by the new jet fuel derived from manure.
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