An experimental new wing flap, designed and developed by FlexSys Inc., is being jointly tested by NASA and the U.S. Air Force Research Laboratory (AFRL) for the Adaptive Compliant Trailing Edge (ACTE) project. A Gulfstream III business aircraft’s wings are being retrofitted to facilitate the testing of the flaps.
NASA’s first series of tests were recently completed at the Armstrong Flight Research Center located in Edwards, California. Installing the shape-shifting flap is a revolutionary concept designed to reduce operating costs and improve aircraft efficiency.
Both of the Gulfstream III aluminum wing flaps were replaced with 19-foot shape changing ones. These flaps eliminate gaps that normally exist when flaps are lowered during take-off and landing. Made of a composite material, the patented design conforms to the wing by forming a continuous, bendable surface.
Initial testing on Oct. 31, 2014 included a 20-degree flap extension during taxiing as well as in-flight data gathering. Results of the flight information will help determine whether this new, lightweight design can reduce fuel consumption, improve environmental noise concerns and reduce structural weight of the wings.
At NASA’s Armstrong Flight Research Center, the ACTE was tested at a 20-degree deflection angle on Oct.31, 2014. Test results were focused on fuel consumption, effects on environmental noise and aerodynamic efficiencies of the craft. Once test results are analyzed, NASA will also discern whether advanced light-weight materials can be utilized in the flaps’ seamless design to reduce wing weight.
While aerodynamic improvements have been introduced in airplane designs over the years, aircraft wings have remained fundamentally unchanged. They remain clumsy and noisy. Flaps are instrumental in the aircraft’s ability to ascend, descend, bank, change speeds and for landings and take-offs. Mechanical operation of the wing flaps reduces a plane’s efficiency and adds to the noise.
FlexFoil is the name attributed to the shape changing flaps. They can adjust their shape in flight to generate a smooth, seamless wing surface. FlexFoil’s pliability allows it to simulate a flap while still maintaining a continuously smooth surface. What makes the new shape-shifting flaps attractive is that they can be retrofitted onto existing aircraft as well as new ones.
For this first test, the flaps remained stationary in one position. Subsequent tests in a wind tunnel will influence flights over the next few months that will test various flap positions.
According to ACTE Project Manager, Thomas Rigby, the initial flight went just as planned. In addition, important elements of the newly designed trailing edge were validated and he expected the ACTE to impact future aircraft efficiency, ultimately saving the industry millions in just fuel costs alone.
As testing continues on FlexFoil to verify its flight capabilities and potential commercial application beyond airplane wing flaps, Sridhar Kota, FlexSys founder and CEO, hopes that the technology can be tailored for specific purposes that continues to increase efficiency while utilizing lighter materials.
As the testing efforts of NASA and the U.S. Air Force continue, it appears viable that this new airplane wing flap will have a dramatic impact on the commercial airline industry. Future aeronautics is expected to be dramatically impacted by the impending deployment of ACTE technology. Peter Flick, Program Manager for the AFRL, feels that ACTE will have a major impact on the aerospace industry.
By Hans Benes
Image courtesy of NASA/Ken Ulbrich