Show simple item record

dc.contributor.author
Iranidokht, Vahid
dc.contributor.author
Papagiannis, Ilias
dc.contributor.author
Kalfas, Anestis I.
dc.contributor.author
Abhari, Reza S.
dc.contributor.author
Senoo, Shigeki
dc.contributor.author
Momma, Kazuhiro
dc.date.accessioned
2021-06-18T08:50:23Z
dc.date.available
2021-06-18T03:47:05Z
dc.date.available
2021-06-18T08:50:23Z
dc.date.issued
2021-09
dc.identifier.issn
0889-504X
dc.identifier.issn
1528-8900
dc.identifier.other
10.1115/1.4050441
en_US
dc.identifier.uri
http://hdl.handle.net/20.500.11850/490248
dc.description.abstract
This paper presents the computational methodology and experimental investigations accomplished to enhance the efficiency of a turbine stage by applying non-axisymmetric profiling on the rotor hub wall. The experimental setup was a two-stage axial turbine, which was tested at "LISA"test facility at ETH Zurich. The first stage was considered to create the flow history for the second stage, which was the target of the optimization. The hub cavity of the second stage was designed with large dimensions as a requirement of a steam turbine. The goal was to optimize the interaction of the cavity leakage flow with the rotor passage flow to reduce the losses and increase efficiency. The computational optimization was completed using a genetic algorithm coupled with an artificial neural network on the second stage of the test turbine. Unsteady time-accurate simulations were performed using in-house developed "MULTI3"solver. Besides implementing all geometrical details (such as hub and tip cavities and fully 3D blade geometries) from the experimental setup into the computational model, it was learned that the unsteady upstream effect could not be neglected. A novel approach was introduced using unsteady inlet boundary conditions to consider the multistage effect while reducing the computational cost to half. The importance of this implementation was tested by performing a steady simulation on the optimized geometry. The predicted efficiency gain from steady simulations was 4.5 times smaller (and negligible) compared to the unsteady approach. Excluding the cavity geometry was also assessed in a different simulation setup showing 3.9% over-prediction in the absolute efficiency value. Comprehensive steady and unsteady measurements were performed utilizing pneumatic, fast response aerodynamic probe (FRAP), and fast response entropy probe (FENT) on the baseline and profiled test cases. The end wall profiling was found to be successful in weakening the strength of the hub passage vortex by a 19% reduction in the under-over turning. As a result, the blockage was reduced near the hub region leading to more uniform mass flow distribution along the span. The flow angle deviations at the higher span position were also corrected due to better control of the flow angles. Furthermore, the improvements were confirmed by reductions in entropy, secondary kinetic energy, and pressure unsteadiness. The accurate computational implementations led to an excellent agreement between the predicted and measured efficiency gain
en_US
dc.language.iso
en
en_US
dc.publisher
American Society of Mechanical Engineers
en_US
dc.subject
Steam turbine
en_US
dc.subject
Uunsteady optimization
en_US
dc.subject
Efficiency
en_US
dc.subject
Endwall profiling
en_US
dc.title
Unsteady steam turbine optimization using high-fidelity computational fluid dynamics
en_US
dc.type
Journal Article
dc.date.published
2021-05-05
ethz.journal.title
Journal of Turbomachinery
ethz.journal.volume
143
en_US
ethz.journal.issue
9
en_US
ethz.journal.abbreviated
J. Turbomach
ethz.pages.start
091006
en_US
ethz.size
12 p.
en_US
ethz.identifier.wos
ethz.identifier.scopus
ethz.publication.place
New York, NY
en_US
ethz.publication.status
published
en_US
ethz.leitzahl
ETH Zürich::00002 - ETH Zürich::00012 - Lehre und Forschung::00007 - Departemente::02130 - Dep. Maschinenbau und Verfahrenstechnik / Dep. of Mechanical and Process Eng.::02668 - Inst. f. Energie- und Verfahrenstechnik / Inst. Energy and Process Engineering::03548 - Abhari, Reza S. / Abhari, Reza S.
ethz.leitzahl.certified
ETH Zürich::00002 - ETH Zürich::00012 - Lehre und Forschung::00007 - Departemente::02130 - Dep. Maschinenbau und Verfahrenstechnik / Dep. of Mechanical and Process Eng.::02668 - Inst. f. Energie- und Verfahrenstechnik / Inst. Energy and Process Engineering::03548 - Abhari, Reza S. / Abhari, Reza S.
ethz.date.deposited
2021-06-18T03:47:10Z
ethz.source
SCOPUS
ethz.eth
yes
en_US
ethz.availability
Metadata only
en_US
ethz.rosetta.installDate
2021-06-18T08:50:29Z
ethz.rosetta.lastUpdated
2021-06-18T08:50:29Z
ethz.rosetta.exportRequired
true
ethz.rosetta.versionExported
true
ethz.COinS
ctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.atitle=Unsteady%20steam%20turbine%20optimization%20using%20high-fidelity%20computational%20fluid%20dynamics&rft.jtitle=Journal%20of%20Turbomachinery&rft.date=2021-09&rft.volume=143&rft.issue=9&rft.spage=091006&rft.issn=0889-504X&1528-8900&rft.au=Iranidokht,%20Vahid&Papagiannis,%20Ilias&Kalfas,%20Anestis%20I.&Abhari,%20Reza%20S.&Senoo,%20Shigeki&rft.genre=article&rft_id=info:doi/10.1115/1.4050441&
 Search print copy at ETH Library

Files in this item

FilesSizeFormatOpen in viewer

There are no files associated with this item.

Publication type

Show simple item record