Dryden Center Innovation Fund Selectees Named
A new Center Innovation Fund seeded through the NASA Office of the Chief Technologist became available when the federal 2011 fiscal year budget passed in April. The goal of the new initiative, funds from which are being offered to agency researchers at each of NASA's field centers, is to stimulate new ideas and encourage pursuit of promising technologies.
Dryden researchers submitted their proposals at the beginning of the fiscal year to David Voracek, Dryden Chief Technologist. So selections could be made from the submissions as soon as funding became available, a group composed of two members from each Dryden directorate ranked the proposals on technical merit, Voracek said.
"The Center Innovation Fund will allow researchers to investigate ideas they would not be able to fund any other way to see if a concept has merit for further study. We hope the research funded by the CIF will lay the groundwork for future NASA investments in developing these emerging technologies, which will leverage Dryden's talents and capabilities," said Voracek.
Four projects were selected to receive funding and are expected to reach established milestones by September. Project researchers are listed alphabetically below with brief descriptions of the projects they will lead.
Two-seat and, soon, six-seat aircraft powered entirely by electricity are closer to becoming reality. The trend is moving toward electrically powered commercial aircraft, and Dryden researcher Jonathan Barraclough wants Dryden to be a driver of this new revolution in technology advancement and integration.
Ideally, an X-plane that integrates all-electric components or a hybrid aircraft with many electric components would be developed and flown at Dryden to validate and verify the concepts and integration, which the commercial sector would then incorporate into new generations of airplanes. Toward that goal, Barraclough earned funding for electric aircraft system technology development that dovetails with Aeronautics Research Mission Directorate visions for less noisy, more fuel efficient and environmentally friendly future aircraft.
Barraclough, an electrical engineer, is specifically interested in electric propulsion, which he said he believes can dramatically increase overall efficiency and reduce environmental impact. Development of new aerodynamic, structural, control and powerplant technologies will be required, but preliminary steps could lead to new breakthroughs to make future visions possible, he said.
His task will be to seek out partners in industry and academia with expertise that can be leveraged in electrical aircraft technologies, combining benefits of related technologies to help surmount technical hurdles in creating all-electric aircraft. A report he will write when his research is complete will focus on partnering possibilities, required test infrastructure for electric aircraft systems development and integration and, potentially, conceptual drawings for test systems.
Algorithms will be needed for moving aeronautics- and physics-based information from sensors to an aircraft's flight control computer in real time and success will open a new frontier in controls and aircraft efficiency.
New aerospace vehicle designs will depend on such an integrated system that can gather information from an aircraft's sensors and feed it into the flight control computer. What's potentially revolutionary is then having the flight control system use new algorithms in harnessing that information to alleviate aerodynamic forces and achieve different system goals, said Dryden researcher Marty Brenner. The research focus will alternately be on handling quality performance, gust-load alleviation and aerostructural stability.
Brenner equates the sensors and their information on an aircraft, feeding back into a fly-by-feel flight control system, to the human nervous system. In the body, signals to the brain from the central nervous system allow a person to react to what is happening, as it's happening. If Brenner is successful, as an aircraft flies, information from the sensors will be fed into the flight controls and allow the aircraft to adapt to flight conditions.
Called Distributive Adaptive Aeroservoelastic Control Utilizing Physics-Based Aerodynamic Sensing, the new technology will be used in pinpointing flow bifurcation points – areas where the airflow characteristics change significantly – to define a relationship between different key parameters.
For example, information on the leading-edge stagnation point, with angle-of-attack or flow separation point and aerodynamic lift coefficient, could be used in the control system for decisions on how to control the aircraft. The system also would help minimize transitions on the aircraft, such as those from laminar-to-turbulent and attached-to-separated airflow, and shock waves.
The capability for flexible motion control will help increase design options for lighter-weight aircraft, which can lead to increased fuel efficiency and reduce noise. Reducing aircraft weight usually means reducing stiffness and increasing flexibility. Increased flexibility translates into an aircraft being more susceptible to aeroelastic phenomena such as flutter, divergence, buzz, buffet and gusts.
For lighter-weight aircraft and spacecraft, use of the new materials and structures, coupled with the new control methodologies, could lead to drastic weight reduction and corresponding cost savings, said Dryden researcher Chan-gi Pak.
In the past, a key way of meeting design challenges with flexible aircraft structures was to design aircraft using ridged materials in areas where designers were worried about aeroservoelastic instabilities. Pak said he wants to change that assumption by seeking to control flexibility motion through an active control system he calls the Active/Adaptive Flexible Motion Controls with Aeroservoelastic System Uncertainties.
He would like to see his control methodology ultimately flown on an aircraft during a flight test. The predicted results of his control laws then would be compared to the actual aircraft measurements and used on a test flight in concert with standard control laws. The capability to turn off the adaptive portion of the system provides a mechanism for comparing the performance of each set of control laws and adding flight safety to early-stage development.
A day may come on which aircraft companies could cooperate to maximize fuel savings and fly aircraft in formation to destinations across the nation. It's a vision Dryden researcher Curt Hanson can see, and he isn't alone.
Gregory Hornby, who has a doctorate in computer science and is a senior scientist at Ames Research Center at Moffett Field, Calif., estimates that if formation flight were applied to just 5 to 10 percent of national airspace traffic, an annual fuel savings of as much as $750 million could be realized.
Dryden research into algorithms that can identify the peak of aerodynamic forces and autonomously reconfigure the airplane to improve efficiency will be key to achieving those levels of savings, Hanson said. Repositioning aircraft surfaces to reduce drag could cut fuel use in half and drastically reduce emissions.
"An aircraft flying in another aircraft's wingtip vortex creates a big rolling moment, and traditional trim schedules deflect the ailerons anti-symmetrically. It turns out that that type of trim scheme is exactly the wrong thing to do when flying in formation for drag reduction.
"CFD [computational fluid dynamics] analysis performed by the flow physics group here at Dryden will determine the optimal control trim configuration scheme, and then I will apply a peak-seeking control algorithm scheme to find that solution in real time," he explained.
The technology is called Wing Morphing for Optimal Drag Reduction in Formation Flight. Futuristic wings may have the capability to alter their own camber and twist to optimize lift distribution in the presence of another aircraft's vortex.
A peak-seeking controller will continually adjust the wing shape and control trim to account for changes in flight condition, aircraft weight and uncertainty in the strength and shape of the leading airplane's vortex.
Eventually, the peak-seeking controller could be tested on a Dryden research aircraft.