THE INFLUENCE OF WAKE-WAKE INTERACTIONS ON LOSS FLUCTUATIONS OF A DOWNSTREAM AXIAL COMPRESSOR BLADE ROW

The interaction between wakes of an adjacent rotor-stator or stator-ro tor blade row pair in an axial turbomachine is known to produce regula r spatial variations in both the time-mean and unsteady flow fields in a frame relative to the upstream member of the pair. This paper exami nes the influence of such changes in the freestream disturbance field on the viscous losses of a following blade row. Hot-wire measurements are carried our downstream of the outlet stator in a 1.5-stage axial c ompressor having equal blade numbers in the inlet guide vane (IGV) and stator rows. Clocking of the IGV row is used to vary the disturbance field experienced by the stator blades; the influence on stator wake p roperties is evaluated. The magnitude of periodic fluctuations in ense mble-averaged stator wake thickness is significantly influenced by IGV wake-rotor wake interaction effects. The changes in time-mean stator losses appear marginal.