10:1 PRESSURE RATIO SINGLE-STAGE CENTRIFUGAL COMPRESSOR PROGRAM

摘要

The objective of this program was to design, fabricate and test a 3.1-lb/sec airflow single-stage centrifugal compressor that could be incorporated in a future Army advanced technology gas turbine engine. The design performance goals were to exceed 75% efficiency at 10:1 pressure ratio. Since gas turbine engines for Army aircraft applications operate under part-power conditions a majority of the time, an off-design performance goal of 80% efficiency at 8:1 pressure ratio was established. In the design of the compressor, parametric studies were conducted to select an overall design consistent with optimum compressor performance at both performance goals. These studies defined the compressor inlet corrected flow rate, impeller inlet hub and tip radii, corrected impeller rotational speed, and inlet prewhirl. Airflow selection and the selection of the hub radius were influenced by the decision to design a compressor that could be used in a small turboshaft engine with a concentric shaft front drive. Demonstrated total-to-static performance was as high as 79.6% efficiency at 8.192:1 pressure ratio and 73.8% efficiency at 10.03:1 pressure ratio. Performance adjusted for increased losses from a damaged diffuser (10.15:1 pressure ratio and 75.9% efficiency) indicates that the basic compressor design would surpass the 10:1 pressure ratio program goal. Evaluation of component performance data revealed that excessive losses occurred in the inducer above 95% of design speed and that a redesign of this component could produce an additional performance improvement at 10:1 pressure ratio.