Numerical simulation of unsteady flow in centrifugal compressor

Numerical simulation of unsteady flow in a transonic centrifugal compressor using commercial software NUMECA is presented, in which the 3-D viscous unsteady flow due to the interaction of rotor/stator is mainly focused on. According to the simulation results, the static pressure coefficients on the surface of the blades are given varied with time. Also the velocity distribution at different time and different sections along the flow direction are illustrated. The study shows that the flow characteristics change with time a lot near the impeller outlet and in the whole diffuser. Due to the transonic flow, the flow at the upstream of the impeller does not change obviously at different time. The simulation shows that the unsteady viscous flow structure in the compressor is more likely to be the actual flow.