High-speed LPT; Transonic cascade; Aerodynamic mechanism; Blade aerodynamic; Experimental test; High Speed; High-speed low-pressure turbine; Loss mechanisms; Low-pressure turbines; Test case; Unsteady wake; Engineering (all)
Abstract :
[en] The ultra-high bypass ratio geared turbofan is a key concept to reduce the environmental impact of the next generation aircrafts. The increase in rotational speed of the low-pressure turbine (LPT) enabled by the geared architecture offers potential benefits in efficiency and considerable savings in engine weight, overall dimension, and cost. High-speed LPTs operate at transonic exit Mach numbers and low Reynolds numbers. For this combination of operating conditions, where compressibility influences the blade aerodynamics and loss mechanisms, there is a critical lack of openly available detailed experimental data concerning the combined effects of unsteady wakes, purge streams, leakages, and secondary flows for CFD models validation. The current research project focuses on the full characterization of an experimental test case concerning the impact of unsteady wakes and purge flows on the blade aerodynamics and loss mechanisms in a high-speed LPT cascade tested at engine-scaled conditions. The extensive experimental dataset is collected in an open-access database, providing novel validation material for comparison with numerical computations. In this two-part paper, a comprehensive study on the design, commissioning and testing of a transonic low-pressure turbine blade at on and off-design is presented. Part I describes the design of components and accurate instrumentation required to investigate steady quasi-3D flows in a linear cascade environment at low-Reynolds and transonic exit Mach numbers. A novel concept to perform blade radial traverses to obtain spanwise distributions of high-resolution blade measurements is presented. The repeatability and periodicity of the rig flow conditions are demonstrated. This work critically evaluates the methodology used for the design and adaptation of the existing rig for testing of unsteady three-dimensional flows in linear cascade experiments.
Disciplines :
Aerospace & aeronautics engineering
Author, co-author :
Simonassi, Loris; Turbomachinery and Propulsion Department, Von Karman Institute for Fluid Dynamics, Sint-Genesius-Rode, Belgium
Gendebien, Samuel ; Université de Liège - ULiège > Aérospatiale et Mécanique (A&M) ; Turbomachinery and Propulsion Department, Von Karman Institute for Fluid Dynamics, Sint-Genesius-Rode, Belgium
The authors thankfully acknowledge the Clean Sky 2 Joint Undertaking for funding of the SPLEEN project (grant agreement 820883) under the European Union's Horizon 2020 research and innovation program. The presented test case will be soon made openly available on an open source online repository.The authors thankfully acknowledge the Clean Sky 2 Joint Undertaking for funding of the SPLEEN project (grant agreement 820883) under the European Union՚s Horizon 2020 research and innovation program. The presented test case will be soon made openly available on an open source online repository.
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