INVESTIGATION OF A HIGH-PRESSURE-RATIO EIGHT-STAGE AXIAL-FLOW RESEARCH COMPRESSOR WITH TWO III - TRANSONIC INLET STAGES INDIVIDUAL STAGE PERFORMANCE CHARACTERISTICS

摘要

The individual, stage performance was determined for an eight-stage axial-flow compressor from circumferential1y fixed radial rake measure¬ments of total temperature and total pressure at the discharge of each stage. The performance of stages 1, 3, 4, 5, and 6 was as anticipated in design and produced a peak pressure ratio considerably above the de¬sign pressure ratio. Stages 2, 7, and 8 produced a peak pressure ratio approximately equal to design. The stages of this compressor were mis¬matched at design speed because of an excessive design boundary-layer al¬lowance in the latter stages, which caused stages 7 and 8 to stall before the design over-all pressure ratio could be obtained. Between 80 and. 90 percent of design speed, the stages were well matched and a peak efficien¬cy of approximately 0-87 resulted. The excessive design boundary-layer allowance in the latter stages affected the low-speed performance favor¬ably, and a relatively high part-speed efficiency was obtained. The knee in the surge line at 63 percent of design speed corresponded to the point at which the first stage came out of stall. It appears that the stall of the first stage at low speeds adversely affected the. Performance of stages 2 to 5.