Measurements of vortex shedding and wake decay downstream of a turbine inlet guide vane

The flow in the second stage stator of a gas turbine with contoured end-wal l is measured in a low speed wind tunnel. The investigation is focused on t he flow in proximity to the blade trailing edge and in the wake. The measur ements include mean velocity, total and static pressure at the cascade exit together with the analysis of intensity and spectral characteristic of tur bulence. Measurements have been carried out using a miniaturized five-hole pneumatic probe developed inhouse and a single hot wire anemometer on a mea surement grid covering different distances from the blade trailing edge. Th e very fine measurement grids tallow a detailed description of secondary fl ows and the possibility to trace the development of the vortex structures i n the trailing edge region. The combined use of the pneumatic probe and of the hot-wire measurements allow to get a wide set of information on mean an d turbulent characteristics of the three-dimensional flow at the exit of th e cascade and identify the changes in the flow at different blade spans.