A Numerical Investigation of Blade Lean Angle Effects on Flow in a Centrifugal Impeller

An established 3-D viscous code (TASCflow3d) for compressible turbulent flow has been used to numerically investigate the effects of lean angle modifications to an existing high performance centrifugal compressor. Numerical results show that an appropriate compound lean can reduce the leakage flow, unload the blade tip and increase the total pressure ratio at a given flow rate while keeping its efficiency at a constant level. They also indicate that a simple lean can marginally improve the impeller efficiency while it lowers the impeller head versus flow curve.