Aerodynamic Performance of a Wingtip-Mounted Tractor Propeller Configuration in Windmilling and Energy-Harvesting Conditions

Research output: Chapter in Book/Conference proceedings/Edited volumeConference contributionScientificpeer-review

11 Citations (Scopus)
785 Downloads (Pure)


Wingtip-mounted tractor propellers enhance aerodynamic performance by attenuating the wingtip vortex with the propeller slipstream and inducing a favorable upwash on the wing. However, the close coupling between propeller and wing means that wing performance may be degraded when the propeller produces negative thrust. This paper analyzes the aerodynamic interaction effects due to the wingtip-mounted propeller under such conditions, that occur when the propeller is windmilling or used for energy harvesting. Experiments in a low-speed wind tunnel and simulations with a RANS solver highlighted the drop in wing performance at negative thrust for the case with inboard-up rotation. The interaction phenomena are reversed compared to the beneficial propulsive case, since the inflow velocity and angle of attack are now reduced on the part of the wing washed by the slipstream. Because of the reversal of the swirl in the slipstream at negative thrust, the interaction is then favorable with outboard-up rotation. For the considered propeller, that was not optimized for operation at negative thrust, the energy-harvesting efficiency was about 10%. This can be improved for future designs by optimizing the blade geometry and pitch setting of the propeller.

Original languageEnglish
Title of host publicationAIAA Aviation 2019 Forum
PublisherAmerican Institute of Aeronautics and Astronautics Inc. (AIAA)
Number of pages17
ISBN (Electronic)978-1-62410-589-0
ISBN (Print)9781624105890
Publication statusPublished - 2019
EventAIAA Aviation 2019 Forum - Dallas, United States
Duration: 17 Jun 201921 Jun 2019

Publication series

NameAIAA Aviation 2019 Forum


ConferenceAIAA Aviation 2019 Forum
Country/TerritoryUnited States
Internet address


Dive into the research topics of 'Aerodynamic Performance of a Wingtip-Mounted Tractor Propeller Configuration in Windmilling and Energy-Harvesting Conditions'. Together they form a unique fingerprint.

Cite this