Session: 32-02 Turbine Tip Flows

Paper Number: 153789

Numerical and Experimental Analysis of the Tip Leakage Flow in a Squealer LPT Blade for Different Operating Conditions 

This study combines experiments and numerical simulations to achieve a deep understanding of the effects induced by varying key parameters affecting tip leakage flow in Low Pressure Turbine (LPT) blades. Specifically, results for flat tip configurations are compared with a squealer tip geometry for different clearance heights, Reynolds numbers, and mass flow ratios simulating coolant flow ejected from the tip.

Experimental results map the effects of these parameters on loss generation, while detailed insights into the interaction between the tip vortex and other vortical structures within the passage are discussed through CFD simulations. Available experimental data include 2D distributions of total pressure and flow angles measured with a five-hole pressure probe downstream of the cascade for different operating conditions, enabling fine tuning of the numerical simulations.

The RANS solver provides visualizations of streamlines developing close to the tip region, offering a clear interpretation of the mechanism by which cross flow motion in the tip region interacts with the pressure gradient to generate the passage vortex. Additionally, the study explores how these processes vary with tip gap height and different mass flow ratios. The flow Reynolds number effect is also invastigated to provide a comprehensive view on the development of secondary flow system.

Presenting Author: Matteo Dellacasagrande University of Genova

Presenting Author Biography: Research Fellow at the University of Genova, Italy

Authors:

Daniele Petronio Università degli Studi di Genova - DIME
Matteo Dellacasagrande University of Genova
Davide Lengani University of Genova
Luca De Vincentiis Morfo Design
Gabriele Cattoli Morfo Design
Simone Paccati Morfo Design
Filippo Rubechini Morfo Design
Monica Gily Avio Aero
Andrea Notaristefano Avio Aero