Details
| Original language | English |
|---|---|
| Pages (from-to) | 1-14 |
| Number of pages | 14 |
| Journal | Journal of the Global Power and Propulsion Society |
| Volume | 5 |
| Publication status | Published - 26 Jan 2021 |
Abstract
The aim of this work is the decomposition, quantification, and analysis of losses related to the axial-gap size effect in a 1.5-stage low-pressure turbine. Both experimental data and unsteady RANS calculations are investigated for axial gaps equal to 20%, 50% and 80% of the stator axial chord. A framework for identifying sources of loss typically encountered in turbomachinery is derived and utilized for the low-pressure turbine presented. The analysis focuses on the dependency between these losses and the axial-gap vari-ation. It is found that two-dimensional profile losses increase for smaller gaps due to higher wake-mixing losses and unsteady wake-blade interaction. Losses in the end-wall regions, however, decrease for smaller gaps. The total system efficiency can be described by a superposition of individual loss con-tributions, the optimum of which is found for the smallest gap investigated. It is concluded that these loss contributions are characteristic for the medium aspect-ratio airfoils and operating conditions investigated. This establishes a deeper physical understanding for future investigations into the axial-gap size effect and its interdependency with other design parameters.
Keywords
- Axial gap, Axial turbines, CFD, Loss breakdown, Turbine efficiency
ASJC Scopus subject areas
- Engineering(all)
- Aerospace Engineering
- Engineering(all)
- Industrial and Manufacturing Engineering
- Engineering(all)
- Mechanical Engineering
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In: Journal of the Global Power and Propulsion Society, Vol. 5, 26.01.2021, p. 1-14.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Loss assessment of the axial-gap size effect in a low-pressure turbine
AU - Oettinger, Marcel
AU - Mimic, Dajan
AU - Henke, Michael
AU - Schmunk, Oleg
AU - Seume, Joerg R.
N1 - Funding Information: MTU Aero Engines AG.
PY - 2021/1/26
Y1 - 2021/1/26
N2 - The aim of this work is the decomposition, quantification, and analysis of losses related to the axial-gap size effect in a 1.5-stage low-pressure turbine. Both experimental data and unsteady RANS calculations are investigated for axial gaps equal to 20%, 50% and 80% of the stator axial chord. A framework for identifying sources of loss typically encountered in turbomachinery is derived and utilized for the low-pressure turbine presented. The analysis focuses on the dependency between these losses and the axial-gap vari-ation. It is found that two-dimensional profile losses increase for smaller gaps due to higher wake-mixing losses and unsteady wake-blade interaction. Losses in the end-wall regions, however, decrease for smaller gaps. The total system efficiency can be described by a superposition of individual loss con-tributions, the optimum of which is found for the smallest gap investigated. It is concluded that these loss contributions are characteristic for the medium aspect-ratio airfoils and operating conditions investigated. This establishes a deeper physical understanding for future investigations into the axial-gap size effect and its interdependency with other design parameters.
AB - The aim of this work is the decomposition, quantification, and analysis of losses related to the axial-gap size effect in a 1.5-stage low-pressure turbine. Both experimental data and unsteady RANS calculations are investigated for axial gaps equal to 20%, 50% and 80% of the stator axial chord. A framework for identifying sources of loss typically encountered in turbomachinery is derived and utilized for the low-pressure turbine presented. The analysis focuses on the dependency between these losses and the axial-gap vari-ation. It is found that two-dimensional profile losses increase for smaller gaps due to higher wake-mixing losses and unsteady wake-blade interaction. Losses in the end-wall regions, however, decrease for smaller gaps. The total system efficiency can be described by a superposition of individual loss con-tributions, the optimum of which is found for the smallest gap investigated. It is concluded that these loss contributions are characteristic for the medium aspect-ratio airfoils and operating conditions investigated. This establishes a deeper physical understanding for future investigations into the axial-gap size effect and its interdependency with other design parameters.
KW - Axial gap
KW - Axial turbines
KW - CFD
KW - Loss breakdown
KW - Turbine efficiency
UR - http://www.scopus.com/inward/record.url?scp=85116783129&partnerID=8YFLogxK
U2 - 10.33737/jgpps/127834
DO - 10.33737/jgpps/127834
M3 - Article
AN - SCOPUS:85116783129
VL - 5
SP - 1
EP - 14
JO - Journal of the Global Power and Propulsion Society
JF - Journal of the Global Power and Propulsion Society
ER -