Characteristics of lightly loaded fan rotor blade wakes

Abstract

Low subsonic and incompressible wake flow downstream of lightly loaded rotor was studied. Measurements of mean velocity, turbulence intensity, Reynolds stress, and static variations across the rotor wake at various axial and radial locations were investigated. Wakes were measured at various rotor blade incidences to discern the effect of blade loading on the rotor wake. Mean velocity and turbulence measurements were carried out with a triaxial hot wire probe both rotating with the rotor and stationary behind the rotor. Results indicate that increased loading slows the decay rates of axial and tangential mean velocity defects and radial velocities in the wake. The presence of large radial velocities in the rotor wake indicate the extent of the interactions between one radius and another. Appreciable static pressure variations across the rotor wake were found in the near wake region. Similarity in the profile shape was found for the axial and tangential components of the mean velocity and in the outer layer for axial, tangential, and radial turbulence intensities