Experimental and numerical investigation of the performance of a 240 kW centrifugal compressor with different diffusers

Eight low solidity vaned diffusers (LSVD1-LSVD8) were designed for a 240 kW centrifugal compressor. All eight LSVDs and for comprison purposes along with two standard and high performing vaneless diffusers and one conventional vaned diffuser were tested downstream of the same impeller. The objective was to understand the pressure recovery phenomena in each of the three types of diffusers, and the effect of design parameters on performance. Also, the results were compared with the results from numerical simulation. The design parameters include the solidity, turning angle, vane setting angle, and the number of vanes. The experimental investigation was performed at three different rotational speeds (M-u = 0.69, 0.88, 1.02). The experimental results proved the superior merits of the LSVDs relative to the vaneless and vaned diffuser. The LSVDs fulfilled the high expectations, since they seemed to combine the advantages of the conventional diffusers by providing a good pressure recovery over a wide flow range. (C) 2003 Elsevier Inc. All rights reserved.