Abstract

The ingress of hot annulus gas into stator-rotor cavities is an important topic to engine designers. Rim-seals reduce the pressurised purge required to protect highly-stressed components. This paper describes an experimental and computational study of flow through a turbine chute seal. The computations – which include a 360º domain - were undertaken using DLR TRACE’s time-marching solver. The experiments used a low Reynolds number turbine rig operating with an engine-representative flow structure. The simulations provide an excellent prediction of cavity pressure and swirl, and good overall agreement of sealing effectiveness when compared to experiment.
Computation of flow within the chute seal showed strong shear gradients which influence the pressure distribution and secondary-flow field near the blade leading edge. High levels of shear across the rim-seal promote the formation of large-scale structures at the wheel-space periphery; the number and speed of which were measured experimentally and captured, qualitatively and quantitatively, by computations.
A comparison of computational domains ranging from 30º to 360º indicate that steady features of the flow are largely unaffected by sector size. However, differences in large-scale flow structures were pronounced with a 60º sector and suggest that modelling an even number of blades in small sector simulations should be avoided.
Original languageEnglish
JournalJournal of Engineering for Gas Turbines and Power: Transactions of the ASME
Publication statusAccepted/In press - 3 Jul 2019

Cite this

@article{84eac9141d8b4734a07c179223487eff,
title = "Flow Instabilities in Gas Turbine Chute Seals",
abstract = "The ingress of hot annulus gas into stator-rotor cavities is an important topic to engine designers. Rim-seals reduce the pressurised purge required to protect highly-stressed components. This paper describes an experimental and computational study of flow through a turbine chute seal. The computations – which include a 360º domain - were undertaken using DLR TRACE’s time-marching solver. The experiments used a low Reynolds number turbine rig operating with an engine-representative flow structure. The simulations provide an excellent prediction of cavity pressure and swirl, and good overall agreement of sealing effectiveness when compared to experiment. Computation of flow within the chute seal showed strong shear gradients which influence the pressure distribution and secondary-flow field near the blade leading edge. High levels of shear across the rim-seal promote the formation of large-scale structures at the wheel-space periphery; the number and speed of which were measured experimentally and captured, qualitatively and quantitatively, by computations. A comparison of computational domains ranging from 30º to 360º indicate that steady features of the flow are largely unaffected by sector size. However, differences in large-scale flow structures were pronounced with a 60º sector and suggest that modelling an even number of blades in small sector simulations should be avoided.",
author = "Joshua Horwood and {Hualca Tigsilema}, {Fabian Patricio} and Michael Wilson and James Scobie and Carl Sangan and Gary Lock and Johan Dahlqvist and Jens Fridh",
year = "2019",
month = "7",
day = "3",
language = "English",
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 - Flow Instabilities in Gas Turbine Chute Seals

AU - Horwood, Joshua

AU - Hualca Tigsilema, Fabian Patricio

AU - Wilson, Michael

AU - Scobie, James

AU - Sangan, Carl

AU - Lock, Gary

AU - Dahlqvist, Johan

AU - Fridh, Jens

PY - 2019/7/3

Y1 - 2019/7/3

N2 - The ingress of hot annulus gas into stator-rotor cavities is an important topic to engine designers. Rim-seals reduce the pressurised purge required to protect highly-stressed components. This paper describes an experimental and computational study of flow through a turbine chute seal. The computations – which include a 360º domain - were undertaken using DLR TRACE’s time-marching solver. The experiments used a low Reynolds number turbine rig operating with an engine-representative flow structure. The simulations provide an excellent prediction of cavity pressure and swirl, and good overall agreement of sealing effectiveness when compared to experiment. Computation of flow within the chute seal showed strong shear gradients which influence the pressure distribution and secondary-flow field near the blade leading edge. High levels of shear across the rim-seal promote the formation of large-scale structures at the wheel-space periphery; the number and speed of which were measured experimentally and captured, qualitatively and quantitatively, by computations. A comparison of computational domains ranging from 30º to 360º indicate that steady features of the flow are largely unaffected by sector size. However, differences in large-scale flow structures were pronounced with a 60º sector and suggest that modelling an even number of blades in small sector simulations should be avoided.

AB - The ingress of hot annulus gas into stator-rotor cavities is an important topic to engine designers. Rim-seals reduce the pressurised purge required to protect highly-stressed components. This paper describes an experimental and computational study of flow through a turbine chute seal. The computations – which include a 360º domain - were undertaken using DLR TRACE’s time-marching solver. The experiments used a low Reynolds number turbine rig operating with an engine-representative flow structure. The simulations provide an excellent prediction of cavity pressure and swirl, and good overall agreement of sealing effectiveness when compared to experiment. Computation of flow within the chute seal showed strong shear gradients which influence the pressure distribution and secondary-flow field near the blade leading edge. High levels of shear across the rim-seal promote the formation of large-scale structures at the wheel-space periphery; the number and speed of which were measured experimentally and captured, qualitatively and quantitatively, by computations. A comparison of computational domains ranging from 30º to 360º indicate that steady features of the flow are largely unaffected by sector size. However, differences in large-scale flow structures were pronounced with a 60º sector and suggest that modelling an even number of blades in small sector simulations should be avoided.

M3 - Article

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 -