Session: 32-02 Turbine Tip Flows

Paper Number: 151479

Reducing Low-Pressure Turbine Shroud Leakage Loss by Optimizing Leakage-Mainstream Interaction 

In turbomachinery, the mixing that occurs in the blade tip region between the tip leakage and the mainstream flow is associated with an irreversible production of entropy that affects efficiency detrimentally. Despite extensive research efforts in recent years aimed at reducing leakage flows, the mixing process - even at small mass flow rates - still remains a significant source of performance loss. In this context, a promising advance is introduced by Vane Bleed Holes (VBH) (Patent No. EP4123124A1). VBH are bypass channels allowing for the reduction of the mixing losses.

The aim of this paper is to present the numerical design and optimization of a Vane Bleed Hole that will be experimentally integrated and tested in a 1.5-stage low-pressure turbine in future investigations. Within the framework of this study, the VBH geometry is generated, parameterized, and numerically optimized with a genetic algorithm in order to achieve the highest possible increase in isentropic efficiency. The paper particularly focuses on the quantitative assessment of the loss-generating mechanisms using an entropy production-based decomposition of the losses, in order to understand the origin of the integral improvement in the performance. This energetic approach is essential not only for categorizing the loss sources but also for deriving future improvement strategies in the design of VBH.

Presenting Author: Josué-Inocente Camarero Pueyo Institut für Turbomaschinen und Fluid-Dynamik

Presenting Author Biography: 2015 - 2021: Diplôme d'Ingénieur at Institut National des Sciences Appliquées (Lyon, France)
2020 - 2021: M. Sc. at Karlsruher Institut für Technologie (Karlsruhe, Germany)
2021 - current: PhD at Institut für Turbomaschinen and Fluid-Dynamik (Hannover, Germany) under the supervision of Prof. Dr.-Ing. Joerg R. Seume

Authors:

Josué-Inocente Camarero Pueyo Institut für Turbomaschinen und Fluid-Dynamik
Eike Helmsen Institut für Turbomaschinen und Fluid-Dynamik
Marcel Oettinger MTU Aero Engines AG
Stefan Klingl MTU Aero Engines AG
Haris Junghans MTU Aero Engines AG
Kacper Pałkus MTU Aero Engines Polska
Lars Wein Institut für Turbomaschinen und Fluid-Dynamik