Influence of front lean angle on centrifugal compressor performance

The effects of lean angle on compressor performance were investigated using a back swept impeller designed on a computer aided integral design system. Two impellers with 30° and 45° front lean angles were obtained by changing the impeller outlet angle. The flow in a centrifugal compressor with these impellers was then modelled by solving the three-dimension Navier-Stokes equations. The results show that the pressure ratio decreases as the front lean angle increases for the same mass flow. An appropriate front lean angle increases the range of a centrifugal compressor, improves the flow and enhances the isentropic efficiency.