Aerodynamic Performance of a Centrifugal Compressor With Vaned Diffusers

An experimental investigation to improve the stage efficiency through the use of vaned diffusers is presented. Sixteen different vaned diffusers were tested on a model compressor rig. The results showed that the pressure recovery of the vaned diffuser increased up to the critical diffusion ratio, which was shown to be approximately 0.5. The measured pressure distribution around vanes of the well-designed diffusers which had the fair diffusion ratios, were found to agree well with the potential flow solutions. Finally, the importance of the diffuser inlet configuration to the improvement of the stage efficiency is discussed.