Effects of initial and operating conditions on the closed supercritical carbon dioxide Brayton cycle DOI
Senthil Kumar Raman, Jae Sung Park, Simon Song

et al.

Physics of Fluids, Journal Year: 2025, Volume and Issue: 37(3)

Published: March 1, 2025

The supercritical carbon dioxide (s-CO2) power cycle is a potential candidate for efficient thermal energy conversion from various heat sources because of its real gas properties. It necessary to investigate the effects initial thermodynamic conditions they can significantly affect s-CO2 due substantial variation in properties near critical point. In present study, one-dimensional analytical model was developed analyze processes piston engine with as working fluid. Transient computational simulations were performed piston–cylinder dynamic mesh. non-ideal CO2 then estimated using equation state and coupled both calculations. T1 P1 along locus minima Z are found be ideal minimum work input, which could potentially reduce input up 20% compared gaseous CO2. also that increasing slightly above pressure (Pc=73.773 bar) reduces compression work. addition conditions, temperature after introducing regeneration enhanced thermal-to-mechanical conversion, leading higher output, increased efficiency by 105%. requirement state.

Language: Английский

Performance implications of backswept angle in supercritical CO2 centrifugal compressors DOI

Rohith Ambadi S,

Purushothaman Nandagopalan, Senthil Kumar Raman

et al.

Physics of Fluids, Journal Year: 2025, Volume and Issue: 37(3)

Published: March 1, 2025

The performance of a supercritical CO2 centrifugal compressor is critically influenced by the backswept angle blades. This study investigates aerodynamic and thermodynamic impacts varying angles, on parameters such as pressure ratio, isentropic efficiency, flow characteristics, shaft power requirements. Three-dimensional viscous compressible through at steady state numerically simulated with real gas effects mass rate. After essential grid independency test, numerical methodology validated experimental data. At all rates, efficiency ratio decrease an increase in backsweep angle, particularly from 90°. Higher configurations exhibit severe separation energy loss. Due to larger loading, smaller values require relatively higher than configuration angle.

Language: Английский

Citations

1
Direct numerical simulation of the supersonic turbulent boundary layer of supercritical carbon dioxide DOI Creative Commons
Jinhong Wang, Bijie Yang,

Ricardo Martinez-Botas

et al.

Physics of Fluids, Journal Year: 2025, Volume and Issue: 37(2)

Published: Feb. 1, 2025

This paper presents a study of the turbulent boundary layer supercritical carbon dioxide (sCO2) over an adiabatic flat plate using direct numerical simulation (DNS). As non-ideal fluid, sCO2's behaviors in are studied by comparing it with perfect gas air case. Both mean flow and investigated. In addition, skin friction coefficient (Cf) dissipation (Cd) analyzed due to their significance engineering applications. The results reveal that sCO2 has lower temperature variation within than its large Eckert number. By revising Walz's equation, was found equation classic form (using ratios) fails predict profile for sCO2, but enthalpy can accurately distribution. viscosity displays liquid-like behavior inside layer. From fluctuation view, exhibits fluctuations air. Higher velocity intensities introduced local Reynolds number variation. Morkovin's hypothesis is still valid no major differences observed kinetic energy budget between Additionally, van Driest II transformation Cf relations inapplicable compressible fluids, property ratio method suggested as promising alternative. Although Cd at similar level both this study, components behave differently variations.

Language: Английский

Citations

0
Effects of initial and operating conditions on the closed supercritical carbon dioxide Brayton cycle DOI
Senthil Kumar Raman, Jae Sung Park, Simon Song

et al.

Physics of Fluids, Journal Year: 2025, Volume and Issue: 37(3)

Published: March 1, 2025

The supercritical carbon dioxide (s-CO2) power cycle is a potential candidate for efficient thermal energy conversion from various heat sources because of its real gas properties. It necessary to investigate the effects initial thermodynamic conditions they can significantly affect s-CO2 due substantial variation in properties near critical point. In present study, one-dimensional analytical model was developed analyze processes piston engine with as working fluid. Transient computational simulations were performed piston–cylinder dynamic mesh. non-ideal CO2 then estimated using equation state and coupled both calculations. T1 P1 along locus minima Z are found be ideal minimum work input, which could potentially reduce input up 20% compared gaseous CO2. also that increasing slightly above pressure (Pc=73.773 bar) reduces compression work. addition conditions, temperature after introducing regeneration enhanced thermal-to-mechanical conversion, leading higher output, increased efficiency by 105%. requirement state.

Language: Английский

Citations

0