Hot streak evolution in an axial HP turbine stage

The paper presents the results of an experimental study on the evolution of hot streaks generated by gas turbine burners in an un-cooled high-pressure turbine stage. The prescribed hot streaks were streamwise directed and characterized by a 20% over-temperature with respect to the main flow at the stage inlet. The hot streak was injected in four different circumferential positions with respect to the stator blade. Detailed temperature and aerodynamic measurements upstream and downstream of the stage, as well as in-between the blade rows were performed. Measurements showed a severe temperature attenuation of the hot streaks within the stator cascade; some influence on the aerodynamic field was found, especially on the vorticity field, while the temperature pattern resulted severely altered depending on the injection position. Downstream of the rotor, the jet resulted spread over the pitch above midspan and more concentrated at hub. Rotor secondary flows were also enhanced by hot streaks.