Drag Reduction Through Distributed Electric PropulsionOne promising application of recent advances in electric aircraft propulsion technologies is a blown wing realized through the placement of a number of electric motors driving individual tractor propellers spaced along each wing. This configuration increases the maximum lift coefficient by providing substantially increased dynamic pressure across the wing at low speeds. This allows for a wing sized near the ideal area for maximum range at cruise conditions, imparting the cruise drag and ride quality benefits of this smaller wing size without decreasing takeoff and landing performance. A reference four-seat general aviation aircraft was chosen as an exemplary application case. Idealized momentum theory relations were derived to investigate tradeoffs in various design variables. Navier-Stokes aeropropulsive simulations were performed with various wing and propeller configurations at takeoff and landing conditions to provide insight into the effect of different wing and propeller designs on the realizable effective maximum lift coefficient. Similar analyses were performed at the cruise condition to ensure that drag targets are attainable. Results indicate that this configuration shows great promise to drastically improve the efficiency of small aircraft.
Document ID
20140011507
Acquisition Source
Langley Research Center
Document Type
Conference Paper
Authors
Stoll, Alex M. (Joby Aviation, Inc. Santa Cruz, CA, United States)
Bevirt, JoeBen (Joby Aviation, Inc. Santa Cruz, CA, United States)
Moore, Mark D. (NASA Langley Research Center Hampton, VA, United States)
Fredericks, William J. (NASA Langley Research Center Hampton, VA, United States)
Borer, Nicholas K. (NASA Langley Research Center Hampton, VA, United States)
Date Acquired
September 10, 2014
Publication Date
June 16, 2014
Subject Category
Aircraft Design, Testing And Performance
Report/Patent Number
AIAA Paper 2014-2851NF1676L-19130
Meeting Information
Meeting: AIAA Aviation Technology, Integration, and Operations Conference
Location: Atlanta, GA
Country: United States
Start Date: June 16, 2014
End Date: June 20, 2014
Sponsors: American Inst. of Aeronautics and Astronautics