0
research-article

Surface roughness impact on low-pressure turbine performance due to operational deterioration

[+] Author and Article Information
Andreas Kellersmann

Institute of Jet Propulsion and Turbomachinery Technische Universität Braunschweig Hermann-Blenk-Str. 37 Braunschweig 38108, Germany
a.kellersmann@ifas.tu-braunschweig.de

Sarah Weiler

Institute of Jet Propulsion and Turbomachinery Technische Universität Braunschweig Hermann-Blenk-Str. 37 Braunschweig 38108, Germany
sarah.weiler@airbus.com

Christoph Bode

Institute of Jet Propulsion and Turbomachinery Technische Universität Braunschweig Hermann-Blenk-Str. 37 Braunschweig 38108, Germany
chr.bode@ifas.tu-braunschweig.de

Jens Friedrichs

Institute of Jet Propulsion and Turbomachinery Technische Universität Braunschweig Hermann-Blenk-Str. 37 Braunschweig 38108, Germany
j.friedrichs@ifas.tu-bs.de

Joern Staeding

MTU Maintenance Hannover GmbH Münchner Str. 31 30855 Langenhagen, Germany
joern.staeding@mtu.de

Guenter Ramm

MTU Aero Engines AG Dachauer Str. 665 80995 München, Germany
guenter.ramm@mtu.de

1Corresponding author.

ASME doi:10.1115/1.4038246 History: Received July 06, 2017; Revised August 22, 2017

Abstract

The overall efficiency and operational behavior of aircraft engines are influenced by the surface finish of the airfoils. During operation, the surface roughness significantly increases due to erosion and deposition processes. The aim of this study is to analyze the influence of roughness on the aerodynamics of the low-pressure turbine of a mid-sized high bypass turbofan. In order to gain a better insight into the operational roughness structures, a sample of new, used, cleaned and reworked turbine blades and vanes are measured using the confocal laser scanning microscopy technique. The measurement results show local inhomogeneities. The roughness distributions measured are then converted into their equivalent sand grain roughness $k_{s,eq} $ to permit an evaluation of the impact on aerodynamic losses. The numerical study is performed using the CFD-solver TRACE which was validated before with existing data from Rig experiments. The service-induced roughness structures cause an efficiency drop in the low pressure turbine of $\eta_T = -0.16\%$ compared to new parts. A gas path analysis showed that this results in an increased fuel flow of $\Delta \dot m_f = +0.06\%$ and an exhaust gas temperature rise of $\Delta EGT = +1.2 K $ for fixed engine pressure ratio which is equivalent to roughly 4 percent of the typical EGT margin of a fully refurbished engine. This result stresses the importance of roughness induced loss in low pressure turbines.

Copyright (c) 2017 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In