Experimental Results of a Propeller/Wing Interaction Study

The aerodynamic interaction between a propeller and a wing is a source of noise and cyclic loading. Swirl and increased axial velocity in a propeller slipstream can lead to improvement in wing performance, conversely wing performance can be degraded by flow separations caused by the propeller slipstream.

Steady state measurements were done on a propeller and a wing in a tractor configuration, to investigate the consequences of mutual interference on overall performance. These measurements revealed that for certain geometries wing lift is enhanced, and wing drag is decreased. A straight forward physical explanation for this wing behavior is offered.

The unsteady nature of the propeller-wing aerodynamic interaction has been studied using flow visualization. Studying the motion of the propeller tip vortex across the wing revealed that: the tip vortex was severed at the wing leading edge, the severed tip vortex filaments shear in a spanwise direction relative to one another, and these displaced filaments deform to reconnect at the trailing edge. Not only is this information of vortex motion over a wing of interest from a basic hydrodynamic view, but will aid in the interpretation of future unsteady pressure measurements.