TY - GEN
T1 - Effects of purge flow configuration on sealing effectiveness in a rotor-stator cavity
AU - Clark, Kenneth
AU - Barringer, Michael
AU - Johnson, David
AU - Thole, Karen
AU - Grover, Eric
AU - Robak, Christopher
N1 - Publisher Copyright:
Copyright © 2017 ASME.
PY - 2017
Y1 - 2017
N2 - Secondary air is bled from the compressor in a gas turbine engine to cool turbine components and seal the cavities between stages. Unsealed cavities can lead to hot gas ingestion, which can degrade critical components or, in extreme cases, can be catastrophic to engines. For this study, a 1.5 stage turbine with an engine-realistic rim seal was operated at an engine-relevant axial Reynolds number, rotational Reynolds number, and Mach number. Purge flow was introduced into the inter-stage cavity through distinct purge holes for two different configurations. This paper compares the two configurations over a range of purge flow rates. Sealing effectiveness measurements, deduced from the use of CO2 as a flow tracer, indicated that the sealing characteristics were improved by increasing the number of uniformly distributed purge holes and improved by increasing levels of purge flow. For the larger number of purge holes, a fully sealed cavity was possible while for the smaller number of purge holes, a fully sealed cavity was not possible. For this representative cavity model, sealing effectiveness measurements were compared with a well-Accepted orifice model derived from simplified cavity models. Sealing effectiveness levels at some locations within the cavity were well-predicted by the orifice model, but due to the complexity of the realistic rim seal and the purge flow delivery, the effectiveness levels at other locations were not well-predicted.
AB - Secondary air is bled from the compressor in a gas turbine engine to cool turbine components and seal the cavities between stages. Unsealed cavities can lead to hot gas ingestion, which can degrade critical components or, in extreme cases, can be catastrophic to engines. For this study, a 1.5 stage turbine with an engine-realistic rim seal was operated at an engine-relevant axial Reynolds number, rotational Reynolds number, and Mach number. Purge flow was introduced into the inter-stage cavity through distinct purge holes for two different configurations. This paper compares the two configurations over a range of purge flow rates. Sealing effectiveness measurements, deduced from the use of CO2 as a flow tracer, indicated that the sealing characteristics were improved by increasing the number of uniformly distributed purge holes and improved by increasing levels of purge flow. For the larger number of purge holes, a fully sealed cavity was possible while for the smaller number of purge holes, a fully sealed cavity was not possible. For this representative cavity model, sealing effectiveness measurements were compared with a well-Accepted orifice model derived from simplified cavity models. Sealing effectiveness levels at some locations within the cavity were well-predicted by the orifice model, but due to the complexity of the realistic rim seal and the purge flow delivery, the effectiveness levels at other locations were not well-predicted.
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U2 - 10.1115/GT2017-63910
DO - 10.1115/GT2017-63910
M3 - Conference contribution
AN - SCOPUS:85029090508
T3 - Proceedings of the ASME Turbo Expo
BT - Heat Transfer
PB - American Society of Mechanical Engineers (ASME)
T2 - ASME Turbo Expo 2017: Turbomachinery Technical Conference and Exposition, GT 2017
Y2 - 26 June 2017 through 30 June 2017
ER -