Multimethod aerodynamic research of engine-realistic turbine rear structures
Doktorsavhandling, 2024

Despite the significant advancements in aircraft engine technology over the past years, the aerodynamics of engine-realistic turbine rear structures (TRS) remain largely unexplored. The TRS, a structural and aerodynamic component situated downstream of the low-pressure turbine (LPT), plays a pivotal role in engine aerodynamic performance, deswirling the LPT flow to maximize the engine thrust. However, there is a significant gap in available experimental aerodynamic data on state-of-the-art TRS configurations under engine-relevant conditions.

The thesis closes this critical knowledge gap and provides the first comprehensive aerodynamic analysis of the latest and most advanced TRS configurations. Prior studies on the TRS were limited to simplified models. In contrast, this thesis is focused on two TRS types used in all state-of-the-art turbofan engines: with radial and leaned outlet guide vanes (OGVs). For the first time, aerodynamic tests of engine-realistic TRSs have been carried out under engine-relevant Reynolds numbers and flow coefficients, facilitated by a unique annular 1.5 stage LPT-OGV facility at Chalmers University of Technology, established in 2015.

For the experimental investigation of the TRS flow, a multimethod approach was applied and involved an array of advanced measurement techniques to provide insights into various aspects of TRS flow. This included the use of pressure probes and static pressure taps for acquiring total and static pressure distributions, crucial for estimating pressure losses. The oil-film method was employed to capture flow-visualization patterns, serving to indicate laminar-turbulent transition and loss-generating structures. Moreover, for the first time in the context of TRS flow, hot-wire anemometry (HWA) and PIV techniques were employed to provide time-resolved and instantaneous velocity field data, effectively capturing the unsteady phenomena.

The central focus of this thesis is detailed examination of pressure loss mechanisms within TRS, focusing on the impact of different OGV designs and operating conditions on TRS aerodynamics. This involves an in-depth aerodynamic evaluation of multiple OGV types commonly found in real engines, such as regular OGVs, those with increased thickness, and OGVs with integrated engine mount recesses (bumps). For the first time, this study aerodynamically evaluated and compared two engine-realistic TRSs with simultaneously mounted OGVs of different types. The experimental data for the radial TRS was compared with preliminary CFD results, obtained using current industrial tools. The insights obtained from the PIV and HWA campaign were instrumental, allowing for a thorough examination of the structure and propagation of LPT rotor and stator wakes into TRS.

particle image velocimetry

vane lean

pressure taps

enginerealistic

engine-mount recess

European Union (EU)

hot-wire anemometry

outlet guide vanes

oil-film visualization

multi-hole probe

turbine exhaust case

bump

turbine rear frame

computational fluid dynamics.

Clean Sky 2

experimental multimethod approach

Horizon 2020

EATEEM

turbine rear structure

low-pressure turbine

HA4, Hörsalsvägen 4, Campus Johanneberg, Chalmers.
Opponent: Dr. Lars Ellbrant, Technology Demonstrator Director, GKN Aerospace

Författare

Valentin Vikhorev

Chalmers, Mekanik och maritima vetenskaper, Strömningslära

The Influence of the Vane Lean on the Flow In a Turbine Rear Structure

33rd Congress of the International Council of the Aeronautical Sciences, ICAS 2022,;Vol. 7(2022)p. 4819-4825

Paper i proceeding

Experimental and Numerical Flow Analysis of an Engine-Realistic State-of-the-Art Turbine Rear Structure

Journal of Engineering for Gas Turbines and Power,;Vol. 144(2022)

Artikel i vetenskaplig tidskrift

Experimental Flow Analysis in a Modern Turbine Rear Structure with 3D Polygonal Shroud Under Realistic Flow Conditions

European Conference on Turbomachinery Fluid Dynamics and Thermodynamics, ETC,;(2021)

Paper i proceeding

Detailed Experimental Study of the Flow in a Turbine Rear Structure at Engine-Realistic Flow Conditions

Journal of Turbomachinery,;Vol. 143(2021)

Artikel i vetenskaplig tidskrift

Experimental study on the low-pressure turbine wake interaction and development in the turbine rear structure

9TH EUROPEAN CONFERENCE FOR AERONAUTICS AND SPACE SCIENCES,;(2022)

Paper i proceeding

Detailed Experimental Study of the Flow in a Turbine Rear Structure at Engine Realistic Flow Conditions

Proceedings of the ASME Turbo Expo,;Vol. 2B(2020)

Paper i proceeding

Experimental and numerical flow analysis of an engine-realistic state-of-the-art turbine rear structure

Proceedings of the ASME Turbo Expo,;Vol. 2B-2021(2021)

Paper i proceeding

Experimental investigation of waste heat recovery concept in turbine rear structure for a Liquid Hydrogen Gas-Turbine

Proceedings of the International Symposium on Turbulence, Heat and Mass Transfer,;Vol. 1(2023)p. 725-728

Paper i proceeding

The integration of innovative technologies into aircraft engines is a critical and meticulous process, vital for ensuring exceptional performance, reliability, and safety. One of the most crucial stages of this process is the testing and validation of these technologies in a controlled laboratory setting. Therefore, continuous improvement of engine components requires ongoing experimental investigations conducted under engine-relevant conditions.

In support of this, Chalmers University of Technology offers a state-of-the-art facility specifically designed for testing one of the internal engine structures, known as the Turbine Rear Structure (TRS). TRS is a structural component positioned at the aft end of the engine, which transfers mechanical loads from the engine to the aircraft. Moreover, it has aerodynamic function: to deswirl the flow from the last stage of turbine. Such flow management significantly enhances aerodynamic efficiency and engine thrust.

Concerning TRS research, many studies have reached up astage involving laboratory studies to physically validate the analytical predictionsof TRS separate elements. However, these studies were often constrained either bythe lack of engine relevant conditions or relied on simplified models. This reflects alimited experimental database on TRS and highlights the need for comprehensiveTRS validation.

The thesis closes the critical knowledge gap and provides the first comprehensive aerodynamic analysis of the latest and most advanced TRS configurations. This thesis is focused on two TRS types used in all state-of-the-art turbofan engines: with radial and leaned outlet guide vanes (OGVs). For the experimental investigation of the TRS, a multimethod approach was applied and involved an array of advanced measurement techniques to provide insights into various aspects of TRS flow. The experimental results from this work not only offer a valuable database for future CFD simulations but also underscore the need for continued refinement of current industrial CFD tools essential for development of aerodynamically efficient TRS designs.

Aerotermoutveckling för effektiva jetmotorutlopp (AT3E)

VINNOVA (2023-01203), 2023-07-01 -- 2024-06-30.

VINNOVA (2017-04861), 2017-11-10 -- 2022-06-30.

Experimentell aerotermisk studie av nästa generations flygmotorkomponenter

Europeiska kommissionen (EU) (EC/H2020/821398), 2018-10-01 -- 2021-03-31.

Ämneskategorier

Rymd- och flygteknik

Strömningsmekanik och akustik

Infrastruktur

Chalmers strömningslaboratorium

ISBN

978-91-7905-988-0

Doktorsavhandlingar vid Chalmers tekniska högskola. Ny serie: 2024:5454

Utgivare

Chalmers

HA4, Hörsalsvägen 4, Campus Johanneberg, Chalmers.

Online

Opponent: Dr. Lars Ellbrant, Technology Demonstrator Director, GKN Aerospace

Mer information

Senast uppdaterat

2024-02-26