Following the BWB Example
The Boeing Co. Blended Wing Body X-48B flight research project is a success. A second phase to be undertaken at Dryden, as well as a future, larger-scale vehicle, are high on the priority list for the Subsonic Fixed Wing project, said Fay Collier, the project's principal investigator.
Despite anticipated flat or declining future funding for the project, Collier said, "subsonics is a good place to be right now."
The Subsonic Fixed Wing project is part of the Fundamental Aeronautics program under NASA's Aeronautics Research Mission Directorate.
Research with the X-48B is a partnership among NASA, Boeing and the U.S. Air Force Research Laboratories that will have an impact on noise reduction, emissions and fuel economy in future aircraft. After low-speed flight research is complete in phase 1, Collier said plans for a second phase that will be focused on noise reduction are firming up. In addition to low-speed controls work, the current BWB project also incorporates research in structures and noise reduction and fits into a much bigger picture for future aircraft, he said.
According to Collier, the blended wing body aircraft partnership is seen as a model for maximizing research dollars in future collaborations between NASA and private industry. Boeing provides the test asset and NASA provides the range and housing for flight research with the vehicle.
Collier congratulated Gary Cosentino and Tim Risch for their project leadership at Dryden on the blended wing body and its flight tests, which have added to knowledge databases about structures and controls on such an airframe. It is estimated that in the near term a blended wing body aircraft could see increased fuel conservation of 33 percent as compared to that of currently available aircraft.
"The X-48B activity embodies what we're trying to do in subsonics," Collier said. "A second phase for the X-48B is a no-brainer."
A future blended wing body could incorporate propulsion concepts developed at Glenn Research Center, Cleveland, and technologies developed at Langley Research Center, Hampton, Va., that would drastically reduce emissions and improve fuel economy. Everyday use of the X-48B shape will take time to materialize, however; its genesis will be seen in military, then cargo and in future passenger aircraft, Collier explained.
But the aircraft provides both an excellent platform for examining integrated technologies as well as an important example of how NASA aeronautics centers can work together.
"Flight is a key aspect of achieving our goals," Collier said. "Stakeholders like it when we fly concepts on aircraft and we get a lot of mileage from flight research. It also is easy to articulate what we are gaining from a concept when we do it through flight research."
While Collier acknowledged that funding issues are on the horizon and hard decisions will need to be made as to specific projects to be undertaken, there still is room for exploration of fundamental aeronautics concepts requiring flight research. That is especially true in areas that could have an impact on noise and emissions reduction, two constraints on future aviation, he said.
The content of the subsonics program is strong, Collier said, with a slate of current programs under way that are focused on short takeoff and landing, coordination with the Federal Aviation Administration on mutually important issues, noise and emissions reduction and significant increases in overall aircraft performance. How to use flight research as a means of demonstrating and validating advancements in those areas is where Dryden researchers can help.
"The ultimate goal is to get these technologies on aircraft, to benefit people," he said.
Air-to-air refueling and autonomous formation flight are examples Collier gave of past flight research conducted at Dryden that could produce payoffs in as little as five to 10 years and of what NASA should be working toward. Dryden's work with uninhabited aerial systems also is expected to become even more valuable as the nation grapples with regulations and technologies required to bring those aircraft into the national airspace.
Use of new and emerging technologies alone and in combination is expected to produce benefits such as significant advances in fuel economy and in noise and emissions reductions. Three levels of goals for the present, near-term and future have been mapped out by the Aeronautics Research Mission Directorate in the hope that careful planning will lead to revolutions in technology that should provide answers to key aeronautics questions, Collier said. Examples of ready technologies include:
- Ultra-high-bypass engine integration and installation, which could impact progress in noise reduction. Engine design reduces noise by managing pressure and temperature ratios.
- A geared turbofan engine collaboration with Pratt & Whitney involves a type of ultra-high-bypass engine expected to deliver increases in performance and noise reduction. "Technical results are exciting," Collier said. Another effort ratified this year in a Space Act agreement between NASA and General Electric is an open-rotor engine concept, another type of ultra-high-bypass engine. NASA is contributing $3 million and GE $8 million to develop the concept.
- Laminar flow control - the manipulation of air over wing surfaces to reduce drag, previously researched at Dryden with the F-14, JetStar and F-16XL - might be revisited. When fuel costs spike, laminar flow control becomes a hot topic, Collier said. Fuel cost increases have altered the economics of adding laminar flow, which is estimated to reduce fuel consumption by about 29 percent.
- Short-takeoff-and-landing technologies, aerodynamic additions such as the slotted wing and high wing, the larger-scale X-48B, and third-generation fuels could meet some of the emission and performance challenges that will need to be met in aviation's future, Collier said.
"Each technology offers potentially significant results. We're working with the four [NASA] aeronautics centers to find the right approach. One way to do that might be to form (focused task forces) to develop road maps to get these concepts to flight," Collier said.
The Subsonic Fixed Wing program is in its third year and new ideas for taking program concepts from wind tunnels to flight will be sought. To that end, he said, researchers are encouraged to think about the future and how new technologies could meet those challenges, through demonstration in flight projects, to give future designers more confidence in using technologies capable of radically altering the state of aircraft as we know it.
By Jay Levine