The propeller turbulence ingestion problem has been the subject of prior experimental work at the University of Notre Dame. These prior tests focused onthe aeroacoustic response of a four-bladed propeller to grid-generated turbulence. A new project has recently begun, in which the aeroacoustic response characteristics of a ten-bladed propeller ingesting turbulence will be investigated. The initial phase of this project is to characterize the spectral content of the turbulent inflow. Turbulence characterize the spectral content of the turbulent inflow. Turbulence characterization is being performed in three stages. In the first stage, single degree-of-freedom statistical parameters are measured, such as the atuocorrelation and temporal autospectrum of the axial turbulence component, from which estimates of the nominal turbulence intensity and integral scale can by derived. The next task is to determine the spectral content in both the temporal frequency and tangential wave number domains. These data are derived from a series of two-point velocity correlation measurements made along arcs in the tangential direction of the propeller plane. The final turbulence characterization task is to extend the spectral analysis to include the radial wave number domain. The subject of this paper is the data collected during the first two stages of the turbulence characterization. These data demonstrate the expected roll-off characteristics at higher frequencies and wave numbers. In addition to the expected turbulence behavior, a surprising degree of cross-stream spatial structure is demonstrated by the tangential distribution of streamwise velocity.
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