Flow analysis and modeling of centrifugal compressor impellers

Centrifugal compressors performance is heavily affected by impeller design because of the nature of the flow in the impeller. Improvement and modification of a centrifugal impeller is a major task for designers in the turbomachinery field.; A series of impellers' experimental test data was used for the comparison of different configurations and rotational speeds. Four different centrifugal impellers and their modified versions were tested at Solar Turbines. These impellers cover a wide area of specific speeds from 58 to about 135. The comparative study of these test results indicated noticeable compressor stage and impeller performance differences between the original and the modified impellers' configurations. Details are discussed to give a broader understanding for the effect cutting an impeller on its performance as well as the compressor performance.; Comparing the compressor stage and impeller performance of four different rotational speeds has been also done. Since the impellers cover a wide range of the specific speeds, the effect of specific speed on the impeller and stage performance was also another task of this study.; CFX TASCflow, which is a CFD package, was used to simulate the flow. The primary grid generation was done using a FORTRAN code. The CFD and 1-D code results were used to compare with the experimental result. More details will be given throughout this dissertation to help understand the flow in such device in order to improve it.