Turbulence intensity measurements across a NGV cooled cascade with representative Lean Burn combustor outflow

Authors

Tommaso Bacci - University of Florence
Alessio Picchi - University of Florence
Tommaso Lenzi - University of Florence
Bruno Facchini - University of Florence

Abstract

Significant turbulence levels can be achieved at the exit of modern lean-burn aeroenginecombustors, due to the limited interaction between swirling mainflow and liner flows. Inthis study, hot wire anemometry was exploited to assess the turbulence intensity acrossa film-cooled NGV cascade, installed downstream of a non-reactive lean burn combustorsimulator. The interpretation of the turbulence measurements was improved thanks tothe average flow field and pressure results, gathered by five hole probe investigation. Theresults showed that the swirling mainflow was responsible for very high turbulence inten-sities on the combustor exit plane. Important turbulence intensities were also found at theNGV exit, due to the conservation of the residual swirling structure and to its interactionwith the endwall flows. The effect of nozzle film-cooling injection was also assessed: alimited effect was found, with film-cooling injection generally leading to slightly reducedturbulence intensities.