SOME VORTICAL PHENOMENA IN FLOWS OVER TRANSONIC TURBINE NOZZLE VANES HAVING BLUNT TRAILING EDGES

摘要

Results are presented from cascade testing on the nozzle blading of a highly loaded turbine stage. This blading had imparted an unusual redistribution of total temperature to the downstream flow field. The vanes had a blunt trailing edge, causing strong vortex shedding; this was found to be the cause of the temperature anomalies. At transonic speeds unusual vortex configurations were also observed; base pressure measurements revealed a stronger base pressure deficit throughout the Mach number range than existing correlations. Flow visualization studies aided theunderstanding of the secondary flows. In this paper ten different vortical phenomena arising in the one nozzle flow passage are identified.