PRANDTL-D Sub-Scale Glider

PRANDTL-D Sub-Scale Glider

Armstrong researchers are experimenting with a new wing shape that could significantly increase aircraft efficiency. The team has built upon the research of the German engineer Ludwig Prandtl to design and validate a scale model of a non-elliptical wing that reduces drag and increases efficiency. The approach to handling adverse yaw

employs fine wing adjustments rather than an aircraft's vertical tail. The Preliminary Research Aerodynamic Design To Lower Drag (PRANDTL-D) wing addresses integrated bending moments and lift to achieve an

11 percent drag reduction. In a propeller application, efficiency could increase by 13 percent.

Work to date: In 2013, the team developed, demonstrated, and validated a scale model of an improved PRANDTL-D wing. Initial results from a 4-month, small-scale flight experiment unequivocally established proverse yaw. Additionally, preliminary results of the parameter estimation show the correct sign and comparable magnitude to the analysis.

Looking ahead: Next steps are to build and test a propeller with the PRANDTL-D configuration.

Benefits

 Highly efficient: Increases total aircraft efficiency by as much as 62 percent, including efficiency increases in the areas of wing (12.5 percent), drag reduction (25 percent), and use in propulsion systems (13 percent)

 Quieter: Decreases noise

 Faster: Allows aircraft to fly faster

Applications

 Aircraft

 Turbines

 Energy delivery systems

Efficient Aerospace Vehicle Technologies

Increasing efficiency in aerospace systems is a key goal across the spectrum of NASA operations.

Armstrong researchers are constantly striving to build efficiency into all phases of flight projects, through development, fabrication, and operations processes.

From a new wing design that could exponentially increase total aircraft efficiency to a novel test stand for single-engine electric aircraft, our researchers are finding unique solutions that increase efficiency.