Book Description

In view of the importance to contemporary turbocompressor design of increasing the efficiency of low-capacity, high-pressure, centrifugal compressors, and the difficulties engendered by the small discharge volumes, the paper summarizes and evaluates the results obtained in tests of such compressor stages. Tests were carried out on 9 configurations of intermediate stages (impeller-diffuser-return bend and channel) and 3 configurations of terminal stages (impeller-diffuser). All the impellers had a relative width b2/D2 of approximately 0.02; the intermediate stage impellers had a diameter D2 of 352 mm and were tested at tip speeds of 300-315 m/sec., while the terminal stage impellers were 220-256 mm in diameter and were tested at 196-229 m/sec. Three types of diffusers (channeled, vaned and vaneless) were used for the intermediate stages, while the terminal stages were tested only with vaned diffusers. The effectiveness of a particular stage was evaluated on the basis of the stage efficiency, impeller efficiency, diffuser efficiency, stage pressure coefficient, stage pressure ratio, impeller pressure ratio, drag coefficient of the stationary parts, relative loss coefficient of the stagnation pressure, degree of reaction, Mach number, Reynolds number, flow coefficient, discharge rate and the angles of incidence of flow. (Author).