Effects of reynolds number and heat transfer on scaling of a centrifugal compressor impeller

In this paper, the influence of Reynolds number and heat transfer on scaling of a small scale centrifugal compressor impeller was investigated. The flow solver EURANUS, integrated in the FINE/Turbo interface, was used in the numerical simulation. With the application of the similarity principle, the baseline impeller was scaled with a factor of 1/5 and 5 respectively. Using the baseline impeller as reference, an exponential relation between efficiency loss and Reynolds number was used in this study. By comparing Reynolds exponent n of the scaled-up and the scaled-down impellers under adiabatic wall condition, the effect of Reynolds number on scaling of this small scale impeller was studied. The effect of heat transfer was investigated by comparing the results under two different wall conditions (isothermal and adiabatic). This work provides general guidelines for performing scaling designs for small scale centrifugal impellers.