Large Eddy Simulation of Externally Induced Ingress about an Axial Seal by Stator Vanes

Turbine inlet temperatures in advanced gas turbines could be as high as 2000 °C. To prevent ingress of this hot gas into the wheelspace between the stator and rotor disks, whose metals can only handle temperatures up to 850 °C, rim seals and sealing flows are used. This study examines the abilities...

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Main Authors: Sabina Nketia, Kenneth Mark Bryden, Richard Dalton, Tom I-P. Shih
Format: Article
Language:English
Published: MDPI AG 2023-08-01
Series:Energies
Subjects:
Online Access:https://www.mdpi.com/1996-1073/16/16/5985
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author Sabina Nketia
Kenneth Mark Bryden
Richard Dalton
Tom I-P. Shih
author_facet Sabina Nketia
Kenneth Mark Bryden
Richard Dalton
Tom I-P. Shih
author_sort Sabina Nketia
collection DOAJ
description Turbine inlet temperatures in advanced gas turbines could be as high as 2000 °C. To prevent ingress of this hot gas into the wheelspace between the stator and rotor disks, whose metals can only handle temperatures up to 850 °C, rim seals and sealing flows are used. This study examines the abilities of large eddy simulation (LES) based on the WALE subgrid model and Reynolds-averaged Navier–Stokes (RANS) based on the SST model in predicting ingress in a rotor–stator configuration with vanes but no blades, a configuration with experimental data for validation. Results were obtained for an operating condition, where the ratio of the external Reynolds number to the rotational Reynolds number is 0.538. At this operating condition, both LES and RANS were found to correctly predict the coefficient of pressure, C<sub>p</sub>, located downstream of the vanes and upstream of the seal, but only LES was able to correctly predict the sealing effectiveness. This shows C<sub>p</sub> by itself is inadequate in quantifying externally induced ingress. RANS was unable to predict the sealing effectiveness because it significantly under predicted the pressure drop in the hot gas path along the axial direction, especially about the seal region. This affected the pressure difference across the seal in the radial direction, which ultimately drives ingress.
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spelling doaj.art-e792dd4ed59b4bcaacd340ec2656339d2023-11-19T00:57:03ZengMDPI AGEnergies1996-10732023-08-011616598510.3390/en16165985Large Eddy Simulation of Externally Induced Ingress about an Axial Seal by Stator VanesSabina Nketia0Kenneth Mark Bryden1Richard Dalton2Tom I-P. Shih3School of Aeronautics and Astronautics, Purdue University, West Lafayette, IN 47907, USAAmes National Laboratory, United States Department of Energy, Ames, IA 50011, USANational Energy Technology Laboratory, United States Department of Energy, Morgantown, WV 26505, USASchool of Aeronautics and Astronautics, Purdue University, West Lafayette, IN 47907, USATurbine inlet temperatures in advanced gas turbines could be as high as 2000 °C. To prevent ingress of this hot gas into the wheelspace between the stator and rotor disks, whose metals can only handle temperatures up to 850 °C, rim seals and sealing flows are used. This study examines the abilities of large eddy simulation (LES) based on the WALE subgrid model and Reynolds-averaged Navier–Stokes (RANS) based on the SST model in predicting ingress in a rotor–stator configuration with vanes but no blades, a configuration with experimental data for validation. Results were obtained for an operating condition, where the ratio of the external Reynolds number to the rotational Reynolds number is 0.538. At this operating condition, both LES and RANS were found to correctly predict the coefficient of pressure, C<sub>p</sub>, located downstream of the vanes and upstream of the seal, but only LES was able to correctly predict the sealing effectiveness. This shows C<sub>p</sub> by itself is inadequate in quantifying externally induced ingress. RANS was unable to predict the sealing effectiveness because it significantly under predicted the pressure drop in the hot gas path along the axial direction, especially about the seal region. This affected the pressure difference across the seal in the radial direction, which ultimately drives ingress.https://www.mdpi.com/1996-1073/16/16/5985rim sealsexternally induced ingressgas turbines
spellingShingle Sabina Nketia
Kenneth Mark Bryden
Richard Dalton
Tom I-P. Shih
Large Eddy Simulation of Externally Induced Ingress about an Axial Seal by Stator Vanes
Energies
rim seals
externally induced ingress
gas turbines
title Large Eddy Simulation of Externally Induced Ingress about an Axial Seal by Stator Vanes
title_full Large Eddy Simulation of Externally Induced Ingress about an Axial Seal by Stator Vanes
title_fullStr Large Eddy Simulation of Externally Induced Ingress about an Axial Seal by Stator Vanes
title_full_unstemmed Large Eddy Simulation of Externally Induced Ingress about an Axial Seal by Stator Vanes
title_short Large Eddy Simulation of Externally Induced Ingress about an Axial Seal by Stator Vanes
title_sort large eddy simulation of externally induced ingress about an axial seal by stator vanes
topic rim seals
externally induced ingress
gas turbines
url https://www.mdpi.com/1996-1073/16/16/5985
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AT richarddalton largeeddysimulationofexternallyinducedingressaboutanaxialsealbystatorvanes
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