On the aerodynamics and heat transfer of a high-speed turbine with advanced rotor tip geometries
(2020)
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- Authors
- Supervisors
- Arts, Tony
- Abstract
- Modern aeroengines design is driven by the pursuit of maximized performance, reduced fuel consumption and increased lifespan. The achievement of these conflicting objectives depends on the performance and longevity of the high pressure turbine (HPT). The leakage flow generated in the gap between the rotor blades and the shroud is responsible for up to one third of the stage losses and generates critical thermal stresses on the wetted parts. This study targets an in-depth understanding of the flow physics established by two optimized rotor tip designs, one with a contoured shape and one presenting a multi-cavity geometry, against a conventional squealer. The experiments are performed at engine-representative flow conditions in the high-speed turbine rig of the von Karman Institute. The HPT stage is heavily instrumented for high-bandwidth aerodynamic and heat-transfer measurements and operates a rainbow rotor for the simultaneous testing of multiple tip designs. Time-resolved aerothermal measurements are combined with steady and unsteady CFD to evaluate the over-tip flow and turbine outlet flow field. The CFD-tracked rotor vortical structures are validated experimentally and a modal analysis tool is developed to quantify the impact of blade rows interactions on the unsteady HPT flow. The rainbow rotor approach is validated in terms of turbine flow periodicity and operative point. The study validates the aerodynamic and thermal ranking predicted by the tip optimization and demonstrates the impact of the tip geometry on the machine flow physics.
- Affiliations
Citations
Cernat, B. (2020). On the aerodynamics and heat transfer of a high-speed turbine with advanced rotor tip geometries. https://hdl.handle.net/2078.5/121495