Numerical investigation of the influence of variable diffuser vane angles on the performance of a centrifugal compressor

In this study, the performance of a turbocharger compressor system for light-duty diesels, encompassing the airflow geometry from impeller inlet to volute exit, has been simulated numerically, and the effects of variable diffuser vane angles on the compressor performance and operating range have been investigated. It is found that the angle of the diffuser vane has significant influence on the compressor operating range, and optimized design of the variable diffuser vane angle can increase the stable operating range and improve the compressor efficiency significantly when compared with fixed diffuser vane angles and vaneless designs. However, changing the diffuser vane angle alone may not achieve the full control of the operating range of a compressor desired. Other technologies (e.g. variable inlet guide vanes, casing treatment, or optimum impeller design) may also be necessary to achieve the widest operating range required.