Performance enhancement of a centrifugal compressor stage using profiled end wall (PEW) treatments in the radial vaned diffuser

Profiled End Wall (PEW) is an effective method that has been employed in recent years in the field of axial flow turbines as a means to reduce secondary flows and associated losses leading to improved efficiency. However, the application of end wall contouring to control the flow field in the radial vaned diffuser of a centrifugal compressor is new and no previous research has been found for this topic. The centrifugal compressor is the most extensively produced type of high-speed turbomachine and is therefore very important for power and propulsion applications. In order to reveal the impact of PEW on the performance and working range of centrifugal compressors, this study reports the outcomes of numerical simulations that were conducted for different PEW treatments and benchmarked against experimental data from the exemplar open test case known as ‘Radiver’. The results show the potential for the compressor operating range to be significantly extended by up to 39% in PEW cases with no significant decrease in efficiency or pressure ratio.