Numerical loss investigation of a small scale, low specific speed supercritical CO2 radial inflow turbine
Article
Article Title | Numerical loss investigation of a small scale, low specific speed supercritical CO2 radial inflow turbine |
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ERA Journal ID | 3684 |
Article Category | Article |
Authors | Keep, Joshua A. and Jahn, Ingo H. J. |
Journal Title | Journal of Engineering for Gas Turbines and Power: Transactions of the ASME |
Journal Citation | 141 (9) |
Article Number | 091003 |
Number of Pages | 10 |
Year | 2019 |
Publisher | American Society of Mechanical Engineers (ASME) |
Place of Publication | United States |
ISSN | 0742-4795 |
1528-8919 | |
Digital Object Identifier (DOI) | https://doi.org/10.1115/1.4043430 |
Web Address (URL) | https://asmedigitalcollection.asme.org/gasturbinespower/article-abstract/141/9/091003/726690/Numerical-Loss-Investigation-of-a-Small-Scale-Low |
Abstract | Radial inflow turbines, characterized by a low specific speed, are a candidate architecture for the supercritical CO2 Brayton cycle at small scale, i.e., less than 5 MW. Prior cycle studies have identified the importance of turbine efficiency to cycle performance; hence, well-designed turbines are key in realizing this new cycle. With operation at high Reynolds numbers, and small scales, the relative importance of loss mechanisms in supercritical CO2 turbines is not known. This paper presents a numerical loss investigation of a 300 kW low specific speed radial inflow turbine operating on supercritical CO2. A combination of steady-state and transient calculations is used to determine the source of loss within the turbine stage. Losses are compared with preliminary design approaches, and geometric variations to address high loss regions of stator and rotor are trialed. Analysis shows stage losses to be dominated by endwall viscous losses in the stator. These losses are more significant than predicted using gas turbine derived preliminary design methods. A reduction in stator–rotor interspace and modification of the blade profile showed a significant improvement in stage efficiency. An investigation into rotor blading shows favorable performance gains through the inclusion of splitter blades. Through these, and other modifications, a stage efficiency of 81% is possible, with an improvement of 7.5 points over the baseline design. |
Keywords | Blades; Flow (Dynamics); Turbines; Stators; Rotors; Design |
Contains Sensitive Content | Does not contain sensitive content |
ANZSRC Field of Research 2020 | 4012. Fluid mechanics and thermal engineering |
Public Notes | Files associated with this item cannot be displayed due to copyright restrictions. |
Byline Affiliations | University of Queensland |
https://research.usq.edu.au/item/z2156/numerical-loss-investigation-of-a-small-scale-low-specific-speed-supercritical-co2-radial-inflow-turbine
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