Photo credit: www.nasa.gov

NASA Tests Innovative Aircraft Wing Concept for Sustainable Aviation

NASA researchers have discovered that an inverted position can lead to significant insights in aerodynamics. This conclusion emerged from their tests on a unique wing design aimed at enhancing the sustainability of future air travel.

The Advanced Air Transport Technology project at NASA is centered around a 10-foot model, reinforcing the validity of the Transonic Truss-Braced Wing (TTBW) concept. This innovative aircraft design features elongated, slender wings supported by diagonal struts which contribute to increased lift and potential reductions in fuel consumption and emissions for next-generation single-aisle commercial airplanes. Researchers at the Flight Loads Laboratory located within NASA’s Armstrong Flight Research Center in Edwards, California, are utilizing this model, referred to as the Mock Truss-Braced Wing, to confirm the concept and the effectiveness of their testing methodologies.

The Mock Truss-Braced Wing and strut are equipped with instrumentation to record strain and are affixed to a sturdy vertical testing frame. To stabilize the wing during evaluations, wires are hung from an overhead structure. Interestingly, the model has been positioned upside down for these tests, allowing weights to be applied for stress testing. This unconventional setup enables gravity to replicate the lift force that a wing encounters while in flight.

“Utilizing a strut enables us to minimize the structural components needed on the primary wing, reducing overall weight and allowing for a thinner design,” stated Frank Pena, director of the mock wing tests at NASA. “The experiments measure the reaction forces at both the main wing’s base and the strut’s base, providing insights into load distribution between the two components.”

To obtain accurate measurements, the team methodically added weights to the wing and strut. In another series of trials, researchers applied impacts to the wing at designated points using a specialized hammer and monitored the vibrations with integrated sensors.

“Every structure has inherent frequencies influenced by its stiffness and mass,” explained Ben Park, who oversees the mock wing’s ground vibration tests. “Recognizing these frequencies is crucial for predicting how the wing will behave during actual flight conditions.”

This multifaceted approach—applying weights, striking the structure, and observing the resulting vibrations—adds a layer of complexity to the testing process. Nevertheless, Park emphasized that the additional effort is justified if it yields useful data for the engineers. The testing is also notable as it was entirely executed by the NASA Armstrong team, which designed, built, and assembled both the wing and associated testing apparatus.

Having nearly finalized the load calibration and vibration assessments for the 10-foot wing, the team is now focusing on developing a system for testing a larger 15-foot model crafted from a graphite-epoxy composite. This next iteration, known as the Structural Wing Experiment Evaluating Truss-bracing, is being designed and constructed by the Advanced Air Transport Technology TTBW team at NASA’s Langley Research Center in Hampton, Virginia.

The new model will be constructed with a structural design that closely mirrors what could be employed in future commercial aircraft. The objectives of these evaluations include aligning predictions with measured data on strain as well as enhancing testing approaches for innovative aircraft structural designs like the TTBW concept.

Nasa’s Advanced Air Transport Technology initiative is part of the broader Advanced Air Vehicles Program, which focuses on developing and assessing new technologies for aircraft systems while investigating promising concepts in air travel.

Source
www.nasa.gov