Abstract
This 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 directed streamwise 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 in severe alteration depending on the injection position. Downstream of the rotor, the jet spread over the pitch above the midspan and was more concentrated at the hub. Rotor secondary flows were also enhanced by hot streaks.
Highlights
The optimization of a gas turbine engine is crucially influenced by the combination between the combustor and the high pressure turbine (HPT)
These studies suggest that the evolution of the hot streaks within the two cascades involves complex phenomena, which have relevant effects on the aerodynamics of the HPT; they indicate the need of further experimental
This paper presents the results of the first experimental campaign on hot streak migration in the stator and in the rotor of an HPT model, for four different clocking positions between the hot streak and the stator blade, providing a unique dataset for flow analysis and computational model assessment
Summary
The optimization of a gas turbine engine is crucially influenced by the combination between the combustor and the high pressure turbine (HPT). The hot streaks incoming in the turbine stage should be convected throughout the stator channel to be released as high-speed jets, which impinge on the rotor blade pressure side and cause a periodic fluctuation of the rotor incidence angle These features might significantly alter the blade surface temperature, with noteworthy implications on the rotor cooling effectiveness [2]. The residual hot streak entering the rotor induces even more complex features within the rotor blade row, including the generation of further vorticity cores which are pushed towards the endwalls [11], altering the wall temperature in these regions and triggering the development of novel cooling techniques [12] These studies suggest that the evolution of the hot streaks within the two cascades involves complex phenomena, which have relevant effects on the aerodynamics of the HPT; they indicate the need of further experimental. This paper presents the results of the first experimental campaign on hot streak migration in the stator and in the rotor of an HPT model, for four different clocking positions between the hot streak and the stator blade, providing a unique dataset for flow analysis and computational model assessment
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
