Abdeldayem2021_TurboExpo.pdf (1.62 MB)
Comparison of CFD predictions of supercritical carbon dioxide axial flow turbines using a number of turbulence models
conference contribution
posted on 2023-06-10, 06:54 authored by AbdElRahman AbdElDayem, Martin WhiteMartin White, Abdulnaser I SaymaA detailed loss assessment of an axial turbine stage operating with a supercritical carbon dioxide (sCO2) based mixture, namely titanium tetrachloride (CO2-TiCl4 85-15%), is presented. To assess aerodynamic losses, computational fluid dynamics (CFD) simulations are conducted using a geometry generated using mean-line design equations which is part of the work delivered to the SCARABEUS project [1]. The CFD simulations are 3D steady state and employ a number of turbulence models to investigate various aerodynamic loss mechanisms. Two categories of turbulence models are used: Eddy Viscosity and Reynold's Stress models (RSM). The Eddy Viscosity models are the k-?, k-? RNG, k-?, k-? SST and k-? Generalized while the RSM models are BSL, LRR, w-RSM and k-? EARSM. The comparison between different turbulence models showed minor deviations in mass-flow rate, power output and blade loading while significant deviations appear in the loss coefficients and the degree of reaction. It is noted that the k-? model gives the highest loss coefficients and the lowest isentropic efficiencies while most of the RSM models indicate higher efficiencies and lower loss coefficients. At off-design conditions a sensitivity study revealed that the k-? RNG model records the sharpest drop in the isentropic efficiency of 8.24% at low mass flowrate reaching 30% off-design. The efficiency sensitivity is found to be less for the other tested models getting 3.1% drop in efficiency for the LRR RSM model.
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Publication status
- Published
File Version
- Published version
Journal
Proceedings of the ASME Turbo ExpoPublisher
American Society of Mechanical EngineersExternal DOI
Volume
10Page range
1-15Event name
ASME Turbo Expo 2021: Turbomachinery Technical Conference and ExpositionEvent location
OnlineEvent type
conferenceEvent date
7 Jun 2021 - 11 Jun 2021ISBN
9780791885048Department affiliated with
- Engineering and Design Publications
Full text available
- Yes
Peer reviewed?
- Yes
Legacy Posted Date
2023-04-26First Open Access (FOA) Date
2023-04-26First Compliant Deposit (FCD) Date
2023-04-26Usage metrics
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