NUMERICAL COMPUTATION OF THE PERFORMANCE MAP OF A SUPERCRITICAL CO2 RADIAL COMPRESSOR BY MEANS OF THREE-DIMENSIONAL CFD SIMULATIONS

The performance map of a radial compressor operating with supercritical CO2 is numerically computed by means of three dimensional steady state Reynolds-averaged Navier Stokes simulations. The results concern a 250 kW prototype. An in-house fluid dynamic solver is coupled with a thermodynamic library which ensures the highest accuracy of the thermophysical properties evaluation. Look-up table interpolation is used in order to reduce the computational cost, while keeping the desired level of accuracy in the fluid characterization. The compressor map is calculated considering three different rotational speeds (45 krpm, 50 krpm, and 55 krpm). For each speed-line several mass flow rates are simulated. Numerical results are compared to experimental data to prove the potential of the methodology.