Propeller Unsteady Thrust due to Operation in Turbulent Inflows

Abstract

In order to better understand the broadband radiated sound and vibrations due to a propulsor blade row operating in a turbulent inflow, an experimental and analytical investigation of the unsteady thrust response of a series of propellers due to operation in turbulent inflows having various characteristic parameters was conducted. The propeller variable considered was blade spacing. The turbulence variables considered were characteristic length scale and intensity. Homogeneous, isotropic turbulence was considered. The propeller unsteady thrust spectra were measured for each propeller over a range of turbulent inflow conditions. Comparisions of experimental spectra with those due to two different analytical methods are made. Conclusions are drawn regarding the accuracy of the two analytical methods.