Computational fluid-dynamic modelling of two-phase compressible flows of carbon dioxide in supercritical conditions

2021 ◽  
Vol 190 ◽  
pp. 116816
Author(s):  
Alessandro Romei ◽  
Giacomo Persico
Keyword(s):  
Carbon Dioxide ◽  
Computational Fluid Dynamic ◽  
Compressible Flows ◽  
Fluid Dynamic ◽  
Dynamic Modelling ◽  
Two Phase ◽  
Supercritical Conditions

scholarly journals Computational Fluid Dynamic Modelling of Thermal Periodic Stabilized Regime in Passive Buildings

2016 ◽  
Vol 8 (11) ◽  
pp. 1172 ◽  
Author(s):  
Fabio Nardecchia ◽  
Benedetta Mattoni ◽  
Francesca Pagliaro ◽  
Lucia Cellucci ◽  
Fabio Bisegna ◽  
...  
Keyword(s):  
Computational Fluid Dynamic ◽  
Fluid Dynamic ◽  
Dynamic Modelling

scholarly journals Computational fluid dynamic modelling of NOx formation in diesel engine

2020 ◽  
Vol 788 ◽  
pp. 012067
Author(s):  
S S Hoseini ◽  
G Najafi ◽  
B Ghobadian ◽  
H Azimi-Nejadian ◽  
Hossein Ahmadian
Keyword(s):  
Diesel Engine ◽  
Computational Fluid Dynamic ◽  
Fluid Dynamic ◽  
Dynamic Modelling ◽  
Nox Formation

Implications of Phase Change on the Aerodynamics of Centrifugal Compressors for Supercritical Carbon Dioxide Applications

2021 ◽  
Vol 143 (4) ◽  
Author(s):  
Giacomo Persico ◽  
Paolo Gaetani ◽  
Alessandro Romei ◽  
Lorenzo Toni ◽  
Ernani Fulvio Bellobuono ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Power Systems ◽  
Phase Change ◽  
Critical Point ◽  
Compressible Flows ◽  
Fluid Dynamic ◽  
Flow Analysis ◽  
Ideal Gas ◽  
New Challenges ◽  
Line Design

Abstract Closed Joule–Brayton cycles operating with carbon dioxide in supercritical conditions (sCO2) are nowadays collecting a significant scientific interest, due to their high potential efficiency, the compactness of their components, and the flexibility that makes them suitable to exploit diverse energy sources. However, the technical implementation of sCO2 power systems introduces new challenges related to the design and operation of the components. The compressor, in particular, operates in a thermodynamic condition close to the critical point, whereby the fluid exhibits significant non-ideal gas effects and is prone to phase change in the intake region of the machine. These new challenges require novel design concepts and strategies, as well as proper tools to achieve reliable predictions. In this study, we consider an exemplary sCO2 power cycle with the main compressor operating in proximity to the critical point, with an intake entropy level of the fluid lower than the critical value. In this condition, the phase change occurs as evaporation/flashing, thus resembling cavitation phenomena observed in liquid pumps, even though with specific issues associated with compressibility effects occurring in both the phases. The flow configuration is therefore highly nonconventional and demands the development of proper tools for fluid and flow modeling, which are instrumental for the compressor design. The paper discusses the modeling issues from the thermodynamic perspective, then highlighting their implications on compressor aerodynamics. We propose tailored models to account for the effect of the phase change in 0D mean-line design tools as well as in fully three-dimensional (3D) computational fluid-dynamic (CFD) simulations: the former was previously validated for sCO2 compressors, the latter is validated in this paper against experiments of compressible flows of supercritical sCO2 in nozzles. In this way, a strategy of investigation is built-up as a combination of mean-line tools, industrial design experience, and CFD for detailed flow analysis. The investigation reveals that the potential onset of the phase change might alter significantly the performance and operation of the compressor, both in design and in off-design conditions, according to three main mechanisms: incidence effect, front-loading, and channel blockage.

Sign in / Sign up

Export Citation Format

Share Document