Low inertia centrifugal compressor wheels: Influence of back disk cavity on aerodynamic losses and axial thrust load

摘要

The influences of back disk cavities on centrifugal compressor aerodynamic losses and axial thrusts are evaluated based on numerical simulations. The influences on compressor performance are found to be negligible. Nevertheless, the consideration of the back disk cavity is necessary for the prediction of axial thrusts and back disk cavity power losses. For this reason, simple analytical equations are proposed for the prediction and the results compared to the numerical simulations. The empirical results show an acceptable agreement concerning pressure prediction at the back disk. To improve the empirical solution, a new approach for the circumferential velocity prediction is introduced.