Flowfield Investigation at Propeller Thrust Reverse

The flow phenomena in the slipstream around an eight-bladed propeller at thrust reverse conditions are analyzed using double stereoscopic particle image velocimetry in the Airbus Low-Speed Wind Tunnel Facility in Bremen, Germany. Several planes are scanned using a traversing system, as well as measurements at several phase angles. In the present paper only properties in the propeller symmetry plane will be compared. The fluid mechanical properties for two different propeller blade pitch angle settings are investigated and compared for their ability to deliver a negative thrust. The first setting has identical blade pitch angles for all propeller blades; the second setting has alternating blade pitch angles. It is concluded that the latter setting provides better aerodynamic flow properties.