Abstract

In modern gas turbines, endwall contouring (EWC) is employed to modify the static pressure field downstream of the vanes and minimise the growth of secondary flow structures developed in the blade passage. Purge flow (or egress) from the upstream rim-seal interferes with the mainstream flow, adding to the loss generated in the rotor. Despite this, EWC is typically designed without consideration of mainstream-egress interactions. The performance gains offered by EWC can be reduced, or in the limit eliminated, when purge air is considered. In addition, EWC can result in a reduction in sealing effectiveness across the rim seal. Consequently, industry is pursuing a combined design approach that encompasses the rim-seal, seal-clearance profile and EWC on the rotor endwall.
This paper presents the design of, and preliminary results from a new single-stage axial turbine facility developed to investigate the fundamental fluid dynamics of egress-mainstream flow interactions. To the authors’ knowledge this is the only test facility in the world capable of investigating the interaction effects between cavity flows, rim seals and EWC. The design of optical measurement capabilities for future studies, employing volumetric velocimetry and planar laser induced fluorescence are also presented. The fluid-dynamically scaled rig operates at benign pressures and temperatures suited to these techniques and is modular. The facility enables expedient interchange of EWC (integrated into the rotor bling), blade-fillet and rim-seals geometries.
The measurements presented in this paper include: gas concentration effectiveness and swirl measurements on the stator wall and in the wheel-space core; pressure distributions around the nozzle guide vanes at three different spanwise locations; pitchwise static pressure distributions downstream of the nozzle guide vane at four axial locations on the stator platform.
Original languageEnglish
Pages (from-to)1-48
Number of pages48
JournalJournal of Engineering for Gas Turbines and Power: Transactions of the ASME
DOIs
Publication statusPublished - 1 Oct 2019

Cite this

@article{bb7de09a6e56482fb7a88837086d57a3,
title = "An advanced single-stage turbine facility for investigating non-axisymmetric contoured endwalls in the presence of purge flow",
abstract = "In modern gas turbines, endwall contouring (EWC) is employed to modify the static pressure field downstream of the vanes and minimise the growth of secondary flow structures developed in the blade passage. Purge flow (or egress) from the upstream rim-seal interferes with the mainstream flow, adding to the loss generated in the rotor. Despite this, EWC is typically designed without consideration of mainstream-egress interactions. The performance gains offered by EWC can be reduced, or in the limit eliminated, when purge air is considered. In addition, EWC can result in a reduction in sealing effectiveness across the rim seal. Consequently, industry is pursuing a combined design approach that encompasses the rim-seal, seal-clearance profile and EWC on the rotor endwall.This paper presents the design of, and preliminary results from a new single-stage axial turbine facility developed to investigate the fundamental fluid dynamics of egress-mainstream flow interactions. To the authors’ knowledge this is the only test facility in the world capable of investigating the interaction effects between cavity flows, rim seals and EWC. The design of optical measurement capabilities for future studies, employing volumetric velocimetry and planar laser induced fluorescence are also presented. The fluid-dynamically scaled rig operates at benign pressures and temperatures suited to these techniques and is modular. The facility enables expedient interchange of EWC (integrated into the rotor bling), blade-fillet and rim-seals geometries. The measurements presented in this paper include: gas concentration effectiveness and swirl measurements on the stator wall and in the wheel-space core; pressure distributions around the nozzle guide vanes at three different spanwise locations; pitchwise static pressure distributions downstream of the nozzle guide vane at four axial locations on the stator platform.",
author = "Robin Jones and Oliver Pountney and Bjorn Cleton and Liam Wood and Buchan Schreiner and {Carvalho Batista Soares De Figueiredo}, {Artur Joao} and James Scobie and David Cleaver and Gary Lock and Carl Sangan",
year = "2019",
month = "10",
day = "1",
doi = "10.1115/1.4045087",
language = "English",
pages = "1--48",
journal = "Journal of Engineering for Gas Turbines and Power: Transactions of the ASME",
issn = "0742-4795",
publisher = "American Society of Mechanical Engineers (ASME)",

}

TY - JOUR

T1 - An advanced single-stage turbine facility for investigating non-axisymmetric contoured endwalls in the presence of purge flow

AU - Jones, Robin

AU - Pountney, Oliver

AU - Cleton, Bjorn

AU - Wood, Liam

AU - Schreiner, Buchan

AU - Carvalho Batista Soares De Figueiredo, Artur Joao

AU - Scobie, James

AU - Cleaver, David

AU - Lock, Gary

AU - Sangan, Carl

PY - 2019/10/1

Y1 - 2019/10/1

N2 - In modern gas turbines, endwall contouring (EWC) is employed to modify the static pressure field downstream of the vanes and minimise the growth of secondary flow structures developed in the blade passage. Purge flow (or egress) from the upstream rim-seal interferes with the mainstream flow, adding to the loss generated in the rotor. Despite this, EWC is typically designed without consideration of mainstream-egress interactions. The performance gains offered by EWC can be reduced, or in the limit eliminated, when purge air is considered. In addition, EWC can result in a reduction in sealing effectiveness across the rim seal. Consequently, industry is pursuing a combined design approach that encompasses the rim-seal, seal-clearance profile and EWC on the rotor endwall.This paper presents the design of, and preliminary results from a new single-stage axial turbine facility developed to investigate the fundamental fluid dynamics of egress-mainstream flow interactions. To the authors’ knowledge this is the only test facility in the world capable of investigating the interaction effects between cavity flows, rim seals and EWC. The design of optical measurement capabilities for future studies, employing volumetric velocimetry and planar laser induced fluorescence are also presented. The fluid-dynamically scaled rig operates at benign pressures and temperatures suited to these techniques and is modular. The facility enables expedient interchange of EWC (integrated into the rotor bling), blade-fillet and rim-seals geometries. The measurements presented in this paper include: gas concentration effectiveness and swirl measurements on the stator wall and in the wheel-space core; pressure distributions around the nozzle guide vanes at three different spanwise locations; pitchwise static pressure distributions downstream of the nozzle guide vane at four axial locations on the stator platform.

AB - In modern gas turbines, endwall contouring (EWC) is employed to modify the static pressure field downstream of the vanes and minimise the growth of secondary flow structures developed in the blade passage. Purge flow (or egress) from the upstream rim-seal interferes with the mainstream flow, adding to the loss generated in the rotor. Despite this, EWC is typically designed without consideration of mainstream-egress interactions. The performance gains offered by EWC can be reduced, or in the limit eliminated, when purge air is considered. In addition, EWC can result in a reduction in sealing effectiveness across the rim seal. Consequently, industry is pursuing a combined design approach that encompasses the rim-seal, seal-clearance profile and EWC on the rotor endwall.This paper presents the design of, and preliminary results from a new single-stage axial turbine facility developed to investigate the fundamental fluid dynamics of egress-mainstream flow interactions. To the authors’ knowledge this is the only test facility in the world capable of investigating the interaction effects between cavity flows, rim seals and EWC. The design of optical measurement capabilities for future studies, employing volumetric velocimetry and planar laser induced fluorescence are also presented. The fluid-dynamically scaled rig operates at benign pressures and temperatures suited to these techniques and is modular. The facility enables expedient interchange of EWC (integrated into the rotor bling), blade-fillet and rim-seals geometries. The measurements presented in this paper include: gas concentration effectiveness and swirl measurements on the stator wall and in the wheel-space core; pressure distributions around the nozzle guide vanes at three different spanwise locations; pitchwise static pressure distributions downstream of the nozzle guide vane at four axial locations on the stator platform.

U2 - 10.1115/1.4045087

DO - 10.1115/1.4045087

M3 - Article

SP - 1

EP - 48

JO - Journal of Engineering for Gas Turbines and Power: Transactions of the ASME

JF - Journal of Engineering for Gas Turbines and Power: Transactions of the ASME

SN - 0742-4795

ER -