Session
2023 session 1
Location
Weber State University
Start Date
5-8-2023 9:25 AM
Description
Emerging advances in electric-propulsion technology are enabling aircraft to use distributed electric propulsion (DEP) to increase performance and maneuverability. Distributed electric propulsion can also provide unique take-off and landing abilities which are not commonly found on traditional aircraft. The implementation of DEP effectively decreases the spacing between propellers, introducing complex aerodynamic interactions that are not well understood. This study aims to present the findings of the effects of phase offset on the flow fields of synchronized propellers at close-proximity using a particle image velocimetry system. The tip vortex locations and peak vorticities were tracked and plotted for various phase offset cases. The tip vortices of the dual propeller cases were found to decay more rapidly than the single propeller case. The momentum flux was integrated across the steroscopic velocity field and compared between the phase offset tests. When compared to the single propeller test, fluctuations of up to 5% were found for the dual propeller cases. Traditional thrust measurements were used to validate this method. When compared to the thrust measurements, the momentum flux was consistently 6-8% lower than the thrust measurements, which is hypothesized to be due to not accounting for pressure acting on the control surface. The results of this work suggests that the potential benefits of controlling propeller phase offset can be realized with negligible effects on propeller flow features and thrust fluctuations.
Aerodynamic Effects of Phase Offset Between Synchronized Propellers in Hover
Weber State University
Emerging advances in electric-propulsion technology are enabling aircraft to use distributed electric propulsion (DEP) to increase performance and maneuverability. Distributed electric propulsion can also provide unique take-off and landing abilities which are not commonly found on traditional aircraft. The implementation of DEP effectively decreases the spacing between propellers, introducing complex aerodynamic interactions that are not well understood. This study aims to present the findings of the effects of phase offset on the flow fields of synchronized propellers at close-proximity using a particle image velocimetry system. The tip vortex locations and peak vorticities were tracked and plotted for various phase offset cases. The tip vortices of the dual propeller cases were found to decay more rapidly than the single propeller case. The momentum flux was integrated across the steroscopic velocity field and compared between the phase offset tests. When compared to the single propeller test, fluctuations of up to 5% were found for the dual propeller cases. Traditional thrust measurements were used to validate this method. When compared to the thrust measurements, the momentum flux was consistently 6-8% lower than the thrust measurements, which is hypothesized to be due to not accounting for pressure acting on the control surface. The results of this work suggests that the potential benefits of controlling propeller phase offset can be realized with negligible effects on propeller flow features and thrust fluctuations.