Impact Factor (2025): 6.9
DOI Prefix: 10.47001/IRJIET
Vol 6 No 3 (2022): Volume 6, Issue 3, March 2022 | Pages: 13-23
International Research Journal of Innovations in Engineering and Technology
OPEN ACCESS | Research Article | Published Date: 18-03-2022
Research and development on the supercritical Brayton power cycle has been powered by its higher thermal efficiency, component compactness, lower corrosiveness, and emission. Modeling of the supercritical fluid flow in a centrifugal compressor passage involves difficulties such as complicated domain, high turbulent intensity, viscus, and unsteady operation in a rotating frame of reference. Furthermore, the variation of supercritical thermophysical requires a robust model to account for real gas behavior. In this work, CFD of three-dimensional Reynolds Averaged Navier-Stokes (RANS) equations are solved to reproduce the flow structure, pressure, and temperature evolution in the centrifugal passages. The Menter turbulence model is used to address the RANS closure problem. The fluid properties are modelled by coupling the CFD solver with the REFPROP database. The Sandia impeller is used in this work to validate the CFD results. Twelve cases of different operating conditions are considered in this work to study the performance of supercritical CO2 centrifugal compressor. The validation results conclude that there is good agreement with the experimental data. The CFD results reveal that the flow velocity varies from 17.9 to 138 m/s as the impeller speed changes from 10000 to 64900 rpm. The flow velocity accelerates faster on the suction side than on the pressure side of both splitter and main blade. Vortical flow is seen behind the trailing edge of vaned diffuser blades due to relatively thick blade at the trailing edge. The tip clearance and secondary flow disturbs the flow at span 90% and intensify the turbulence in the flow. The results also reveal the nonlinear variation of the real fluid thermophysical properties. This behavior imposes considerable challenges to CFD analysis of the centrifugal compressor where the SCO2 density approaches 60% of the water density while fluid being compressed to a pressure ratio up to 1.5.
Three Dimensional CFD, CO2, Flow Characterization, Centrifugal Compressor
Firas Khaleel Hussein Alok, Dr. Younis M. Najim, “Three Dimensional CFD of Supercritical CO2 Flow Characterization in a Centrifugal Compressor” Published in International Research Journal of Innovations in Engineering and Technology - IRJIET, Volume 6, Issue 3, pp 13-23, March 2022. Article DOI https://doi.org/10.47001/IRJIET/2022.603003
This work is licensed under Creative common Attribution Non Commercial 4.0 Internation Licence