EXPERIMENTAL INVESTIGATION OF IMPELLER DIFFUSER INTERACTION IN A CENTRIFUGAL COMPRESSOR

1. EXPERIMENTAL INVESTIGATION OF IMPELLER DIFFUSER INTERACTION IN A CENTRIFUGAL COMPRESSOR Background Transition from circular to annular cross-section Velocity fields in centrifugal compressors have been mostly analyzed using CFD. However, an experimental study is needed to validate the results from the CFD model. Flow direction 5 impeller blades and passages Stationary Cascade Rig Facility, top view Objective Seeding Ports Experimentally investigate the flow field with the use of LDV and design a novel test facility to model the flow of an impeller using a Stationary Cascade Rig Facility. Seeding ports upstream of impeller blades

2. Research Carried Out 10mm diameter A facility has been designed to validate the use of LDV and to show that optical access and seeding into such a highly confined region is possible. Optical access is gained upstream the impeller and throughout the blade passages. Upon validation the LDV technique will be applied to a full-scale compressor test rig. 15mm diameter Optical access upstream of the impeller blades in the Stationary Cascade Rig Facility Expected Outcomes Validation of the LDV technique in highly-confined complex regions. As well, validation of CFD data and improved understanding of the unsteady interactions between the impeller and diffuser flows. “Hub side” optical access into blade passages “Hub side”